6/2009

© AUFWIND-media, Germany 

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AUFWIND-english 

6/2009 

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Editor: Philipp Gardemin 

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Translation: Dieter Mahlein 

(www.shredair.com) 

AUFWIND-english is a trademark of AUFWIND. 

www.AUFWIND-magazine.net 

September/October


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Back issues, plans and more is 

available at 

www.AUFWIND‐media.de 

September/October

Contents 

New Items page 3 

One of the Biggest – “Austria Elefant” (Part 2) page 5 

Pictorials page 7 

Wood soars great – „Climaxx Compact“ von Höllein page 8 

Electro-Eagle – „F3B_Eagle“ by Jiri Tuma page 11 

Electric Duo – „Twin Otter“ by Lindinger page 13 

Retroplane 2009 – Vintage Gliders over Ireland page 15 

SAL-RC-HLG – Or: What might the future look like? page 18 

Scale-Glider News – News from the Scale-Glider Scene page 20 

A worthy successor – „Espadita” von Euromodell page 22 

High-Tech from Swabia – The 2,4-GHz-System by Weatronic page 26 

The 16-Year Project – A scratch-built „ „Grunau-Baby IIb“ page 29 

Tradition meets modern ways – „Premiant II“ by Aeronaut page 31 

A double-meter – „FireworXtend“ by PCM page 33 

Philosophers’ School – A Visit at the RC-Flight-Academy page 35 

Aerobatic Monster – „MDM-1 Fox“ in 1:2 Scale by Paritech page 37 

One Step Further – Step Four introduces a new version of its Milling Software page 40 

Summer-Highlight – 14 years “Flying Circus” page 41 

F3B-WC 2009 – Germany wins ahead of Switzerland and Austria page 43 

A wolf in sheep’s clothes – The „Elektro Trainer S“ by Graupner page 47 

Training Unit – „Epsilon“ by Staufenbiel page 49 

A perfect inaugural event – German Championship for motor-gliders page 52 

Made in Germany – Kontronik celevrates ist 15th anniversary page 53 

Grand Finale – F5B/F5F Eurotour in Austria and Switzerland page 54 

AUFWIND-english is a complete and legible translation 

of the German version, and will be published as an 

supplement together with the German version. The 

printed and bound copy includes all translated text, but 

not the photos and charts accompanying the articles. 

AUFWIND-english will not be issued as a PDF file. 

AUFWIND-english is issued six times per year, always 

during the last week of February, April, June, 

August, October, and December. 

A subscription to AUFWIND-english includes a subscription 

for the German edition. The annual subscription 

including the German issue costs 69.50 € (including 

shipping world-wide). 

The German version of AUFWIND is the leading 

magazine for RC soaring and electric-powered flight. 

It's been issued for more than 20 years now, always at 


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the end of even months (February, April, June, August, 

October, and December). AUFWIND specializes 

in soaring and electric-powered flight. We also 

cover the FAI classes F3B, F3J, F3K, F5B, F5D 

along with glider aerobatics and large-scale gliders. 

AUFWIND addresses the interested and modernthinking 

model pilot and builder. AUFWIND features 

ARFs and foam models less than most other model 

magazines, but instead covers more of building with 

wood and fiber-reinforced resins. Thus, we regularly 

publish articles about building methods using modern 

techniques such as CNC and CAD technologies. 

In addition, we regularly publish articles on 

aerodynamics and the mechanics of flight and reports 

on important events. 

The German issue of AUFWIND is in the internet at 

www.AUFWIND-magazin.de. 

September/October

New Items 

All-Molded Scale 

Wildflug introduces two new all-molded gliders: a “DG- 

600” with the “SD-3021” airfoil and either 2,700 or 

3,200 mm wing spans. The plug-in tips for thermaling 

are white, the shorter slope tips blue or red. The model 

also has built-in spoilers, retract, a finished canopy, 

and a molded pilot’s seat and instrument pod. Price: 

489 Euro. The other model is an ASW-24 with 4 meters 

wing span and all servos installed and wired. Airfoil 

is a HQ 3/15,12,10, and flying weight is between 

5.4 and 8.2 kg. Price: 1,629 Euros. Available from 

Wildflug, tel. +49/172/9003946, www.marioweichelt.de. 

Small Bi-Plane 

Horizon Hobby is offering an attractive ARF-model of 

the “PT-17 Stearman” by E-Flight. The plane has 1,120 

mm wing span and weighs about 1,600 grams. Horizon 

Hobby recommends the “E-Flight Power 15” motor with 

a 3s LiPo 3,200 mAh pack and an APC 12x6 propeller. 

The plane is built-up balsa and plywood and covered in 

Ultracote. Cowl and landing gear are painted fiberglass, 

and a dummy radial engine is included. the 

plane has plug-in wings. The “PT-17 Stearman” is reported 

to look scale in the air and to have excellent 

flying characteristics. Price: 199.90 Euros. Available 

at dealers, www.horizonhobby.de. 

Happy Birthday, Steigeisen 

The Logo-Team notes that the F3K model “Steigeisen” 

has been on sale for a year through Stratair. After 16 

of the 17 Eurotour contests, Raoul Gorka is in first 

place with his “Steigeisen.” The model won four of the 

16 international contests in 2009. Six different wing 

lay-ups are offered now, resulting in different flying 

weights: “Basis” (247g), “Disser” (255g), “Disser 

Space” (245g), “Carbon D-box + Disser” (260g), “Full- 

Carbon” (272g), and “Aramid Space” (255g). According 

to the Logo-Team spars are now made from UMS carbon 

which makes the wing 30% stiffer. Also new is a 

very fine and light Disser fabric called “Space,” which 

has a “gigantic E-modulus,” says the Logo-Team. To 

respond to demands for 2.4 GHz friendly lay-ups, pure 

aramid lay-ups of the fuselage nose now are available 

also. All new aramid fuselages are tested with 8 kg in 

front and 4 kg at the tail. The Logo-Team wants to 

assure reduced delivery times and fast spare parts 

availability: each “Steigeisen” customer will be guaranteed 

to get the parts he needs within 3 weeks, including 

a complete model replacement. Available at 

www.logo-team.biz, www.stratair.com. 


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To be found in AUFWIND at page 6 

2.4-GHz Micro-Receiver 

The new Spektrum receiver “AR-6110” by Horizon 

Hobby was specifically developed for indoor models 

and park flyers. The tiny mite has 6 channels, 

weighs only 3.5 grams and measures 18.8x25x11.6 

and 21x28.7x10 mm, depending on servo pin configuration 

(upright or flat). The antennas are offset 

90 degrees to improve reception. The receivers 

have a red LED which shows the number of holds 

during flight. Price: 49.90 Euros. Available at dealers, 

www.horizonhobby.de. 

New Digital Servos 

Hype is now offering two new IQ-digital servos with 

JR/Hitec connectors by GWS: The “IQ-160DMG” 

and “IQ-180DMG” have metal gears and ball bearings. 

Hype also emphasizes excellent centering, a 

potentiometer with anti-fade coating, and a dustproof, 

fiberglass reinforced case. Four orange servo 

arms and fasteners are included. The “IQ-160DMG” 

has a speed of 0.06 seconds (60 degrees, 4.8 V) 

and 24.46 Ncm of torque; it weighs 19 grams and is 

27x13x27 mm in size. The “IQ-180DMG” uses the 

same case and has a speed of 0.1 seconds (60 

degrees, 4.8 V) and 44.1 Ncm torque. Price for 

either: 31.90 Euros. 

Also in the program are digital servos with plastic 

gear: the “IQ-110DBB” (0.08 seconds to 60 degrees 

at 4.8 V and 11.75 Ncm torque) weighs 8.8 grams 

and is 22x11x21 mm in size. The same goes for the 

“IQ-120DBB, but it weighs 10 grams and is 

22x11x25 mm in size. One size up is the “IQ- 

140DBB” (0.11 seconds to 60 degrees at 4.8V with 

17.64 Ncm torque). It weighs 13 grams and is 

27x13x25 mm in size. Price: 21.90 Euro. Available 

at dealers, www.hype-rc.de. 

Nifty Little Wing 

Hempel Modellflugwelt introduces “Alula,” a bird-like 

design developed specifically for side-arm launches 

(SAL). Wing span is 900 mm, and flying weight is 

170 grams. Wings and fuselage are molded Arcel 

foam which is very light but still strong. Also available 

is the magnet kit known from the “Weasel,” 

with which the wings can be secured. Price: 79 

Euros. Available at Modellflugwelt, tel. 

+49/531/24245-0, www.modellflugwelt.de. 

September/October

Large Receiver 

The “S3D-12+4” is ACT Europe’s 12-channel receiver 

with 16 outlets. It consists of the “S3D-8” receiver, the 

8-channel expander, and an eight centimeter long 

“DSLplus” cable. This way, channels 1 through 12 are 

automatically available without programming, and 

channels 5 though 8 even are doubled up. Servos get 

their power directly through the DSQ plug. This way, 

up to 16 free programmable channels are available. 

Advantages, says ACT, are optimal power distribution 

for the servos and minimizing cables. The system is 

particularly useful when several servos are used for 

one control function. Channel assignment, servo travel, 

and all other attributes can be programmed by computer 

or PDA with a USB or Irda interface. Price: 199 

Euros. Available at ACT Europe, tel. 

+49/7082/93174, www.acteurope.de. 

Master Motor 

F3A top pilot Bernd Beschorner has just become German 

champion using Plettenberg’s “Xtra 30-10 Evo” 

motor. This outrunner is also flown by world champ 

Quique Somenzini, US champ Jason Shulman, and 

Canadian champ Chad Northeast. Plettenberg points 

out that mounting the motor in the spinner offers optimal 

cooling and reduces the transfer of motor torque to 

the air frame. Combined with its vector control, the 

motor delivers more performance and offers optimal 

adaptation to the model and the pilot’s flying style. 

Other features of the “Xtra 30-10 Evo” motor are the 

integrated coupling system, minimal heating, high 

torque, and the ability to withstand high current loads. 

Price: 460 Euros. Available at Plettenberg Elektromotoren, 

tel. +49/5601/97960, www.plettenbergmotoren.com. 

Little Speedster 

Multiplex is now shipping the small e-glider “Merlin.” It 

spans 783 mm, is 598 mm long, and weighs 290 

grams. The little “Merlin” has elevator, rudder, ailerons 

and motor control. The model shines with many clever 

details and a small packing size (11 x 18 x 61 cm). The 

model is made from Elapor and is a real fun-flyer. The 

kit contains molded Elapor parts, small parts, carbon 

spars, decal sheet, and assembly instructions with 

photos. Price is 74.90 Euros. An optional carry bag 

costs 19.90 Euros. Specific power sets for this model 

are “Merlin Tuning,“ which consists of a “Himax C 

2212-1180” motor, a “Multicont BL-20 S-BEC” controller, 

two folding props (7x4 and 8x5), and a 33-mm 

spinner assembly. Price 99.80 Euros. The other set is 

“Merlin Tuning Li-Batt Powered,” which adds a 450 

mAh 3S LiPo battery. Price: 119.80 Euros. Available 

at dealers, www.multiplexrc.de. 


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Flying Transporter 

Bormatec, manufacturer of unmanned cargo aircraft, 

introduces its new model “Maja.” The model is 

designed for aerial photography, surveying, surveillance, 

etc., and is claimed to be an economic and 

universal platform. The model spans 1,800 mm, can 

haul a payload of up to 1.5 kg, and can stay aloft for 

over an hour. The tail-mounted drive train is supposed 

to eliminate electronic interference. Price 

starting at 199.90 Euros. Available at Bormatec, 

tel. +49/7502/940240. www.bormatec.com. 

Hitec Delivers 

Multiplex is announcing the availability of the 2.4 

GHz “Optic 6 AFHSS” radio. It has an 8-model 

memory and can be used for motor planes, gliders, 

and helicopters. Multiplex emphasizes the ergonomic 

case, and the full-featured transmitter. These 

feature include programmable switches; two timers; 

servo travel, reverse, sub-trim, expo, and dual rate 

for channels 1, 2, and 4; and free mixes and buddy 

box ability. Available at dealers, www.hitecrc.de. 

Average-Joe Electro 

Robbe’s “Arcus Sport” is an electro glider made 

from Arcel molded foam for the intermediate modeler. 

It comes complete with a powerful brushless 

outrunner motor and controller, a large folding propeller, 

and aluminum spinner. Six mini-servos and 

all wiring are factory-installed, too. The recommended 

battery is a 3s LiPo with 3,200 mAh capacity. 

Robbe emphasizes that this 4-servo wing has a 

molded-n aluminum tube which makes it torsionally 

stiff. Assembling the “Arcus Sport” only requires 

installing control horns and linkages and attaching 

the decals. The plane has 2,600 mm span and 

weighs about 2,000 grams. Wing loading is listed as 

34.4 g/sqdm. Price: 249 Euros. Available at dealers; 

www.robbe.com. 

Special Edition 

Staufenbiel offers the “Thermik XL” glider in its special 

Staufenbiel-Edition as an all-molded model 

painted in special colors: white fuselage; wing white 

on top with yellow and red stripes, and wide yellow 

and red stripes on the bottom; stabilizer yellow/red; 

ailerons and flaps red. The “Thermik XL” has 4,000 

mm wing span, a kit weight of 2,700 grams, and 

features “SD-7037/MH-32 airfoils. Price: 579 Euros. 

Available at Staufenbiel, Germany, tel. 

+49/40/30061950. www.modellhobby.de. 

September/October

One of the Biggest 

“Austria Elefant” – Part 2 

In AUFWIND 3/2009, we reported about the construction 

of the fuselage and the empennage of this gigantic 

scale model with a 15-meter span. 

Now it was time to start thinking about building the 

wings. While Rolf Fritschi prepared the ribs in “Wingdesign,” 

Hans Baumann was calculating spar dimensions. 

Markus also solicited the help of Max and Ruedi 

Vogelsang who have broad experience in the construction 

of full-sized aerobatic power planes. The conclusion 

was to use “DELIGNIT” plywood for the spar. This 

wood is about three times stronger than Douglas fir in 

bending, compression, and tension. To maintain a high 

degree of torsional stiffness, the spar was designed 

with 54 mm width thoughout the span. It’s 9 mm thick 

at the root and gradually thins to 4 mm at the tip. Because 

this is a 6-piece wing, the wing joiners had to be 

calculated accordingly. Carbon "prepec" tubes by R&G 

were used here. The joiner between the root and center 

panels is 60 mm in diameter, while the one between 

the center and tip panels is 30 mm. This way, 

the spar could be built now, because the ribs were still 

to be made. 

Time to get busy: Install and glue in ribs, fit hinges, cut 

out ailerons, and finally sheet the wing. Nothing special, 

really, just bigger parts than usual. Like the fuselage, 

the whole wing was covered with 49g/qm fiberglass 

fabric and painted with two-component paint. 

Now it was time to obtain the technical certification: 

Emil Hinnen of the Swiss Graupner Service checked 

radio installation and the size and routing of the wiring. 

Installed in the model were 16 “HS-7955” servos with 

24 kg of torque at 6 Volts and a “HS-805 BB” jumbo 

servo. The receiver is a “Dual Receiver 10-20 R” by 

Weatronik on 35 MHz, but we’ll soon switch to 2.4 

GHz. Power comes from one each 2s LiPo 8000 mAh 

and 2s LiPo 3700 mAh batteries. Flying weight is a 

hefty 75 kg. 

With lots of anticipation and a little trepidation, Markus 

waited for the wing static test. Required was a minimum 

of 3G, which, at a fuselage weight of 30 kg, 

meant testing the wing with 90 kg. But to be safe, the 

official at Swiss BAZL (Bundesamt für Zivilluftfahrt), 

Franz Walti, and Markus decided to test with 100 kg. 

To do this, the wings were mounted to a metal frame 

such that positive loads could be tested. It was impressive 

when the wing was bending almost 54 cm under 


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the 100-kg load and the wood started to creak. The 

louder the creaking, the bigger Markus’ eyes – but 

the wing held. Everyone was happy that the wing 

remained undamaged and could now be mounted 

for final certification. Markus especially was very 

relieved. Only two minor issues were identified for 

correction, and planning for the maiden flight could 

begin. It was to take place in early May. 

Markus assembled his “Austria” at the airfield in 

Buttwil and performed control and range checks. 

Unfortunately, St. Peter was uncooperative, because 

it was raining off and on, and strong wind 

gusts prevented the maiden flight for a while. When 

the wind let up later, a test glide was performed: 

Ueli Nyffenegger (TUN Modellbau) piloted the tow 

plane, a 4-meter span “Bellanca” by Fliegerland 

with a 240-cc 3W motor. Ueli added full power, the 

“Austria” got underway and was airborne after only 

about 15 meters. Markus released immediately and 

let the “Austria” glide straight ahead toward a soft 

landing. 

The weather settled down even more an hour later, 

and Markus and Ueli decided to do the first big 

flight. The second tow was as uneventful as the 

first, and Markus released at 300 meters altitude. 

The “Austria” drew its first circles into the Swiss sky. 

Apparently, it never wanted to come down again, 

and due to its size, it looked unbelievably slow. It 

was wonderful to watch how the “Austria” seemingly 

pivoted around a wing tip. All composite plane pilots 

hereby experienced a new dimension of circling, 

and no one dared look away. After 10 minutes, the 

“Austria” touched down smoothly at the airfield. 

Words don’t describe it, you had to have been there 

and experienced first hand how slow such a big bird 

comes in for a landing – it’s like a dream. In the 

months to follow, Markus performed more flights to 

test the performance limits of the “Austria.” One 

memorable flight was at the Wasserkuppe, a very 

historic backdrop. 

Markus again had proven his model building ability 

and showed that it is possible to pull off such a 

huge project within 7 months starting with only a 

small three-view drawing. 

Urs Pircher 

September/October

Photo Captions 

Page 12: 

- Preparing for tow. Notice the drooping wings. 

- 15 meters span and 75 kilos weight are airborne for the first time. 

Page 13: 

- Each detail was carefully inspected by BAZL. 


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Page 14: 

- Wing construction required absolute perfection. 

- All wing joiner systems look very much like a full-size original. 

- When the wing bent 54 cm under 100 kg of weight and the wood was creaking, Markus’ eyes got bigger and bigger. 

- Ueli Nyffenegger (left) towed the “Austria” with a “Decathlon” by Fliegerland. 

- After each flight, the Weatronic receiver system’s log is recorded. It is located in the top of the fuselage. 

- After a few meters, the colossus is airborne. The launch dolly stays behind. 

- The big flaps allow good glide path control. 

- The “Decathlon” has no problems towing the “Austria. 

- A regular van is big enough for transport of the disassembled model. 

___________________________________________________________________________________________ 

experts@internet 

Island Models, Ireland 

phone +353/8 66 03 25 98 

email info@islandmodels.ie 

www.islandmodels.ie 

- Great collection of unusal scale-gliders and products 

from Multiplex, Hitec and others. 

MJD Models, Sweden 

phone +46/70/531 35 31 

email info@mjd.se 

www.mjd.se 

- Wooden kits of "Swedish Aviation Classics", including 

some of the most famous Swedish designs. 

RadioCarbonArt, USA 

Phone +1/888/834-22 61 

email akrouse@ptd.net 

www.radiocarbonart.com 

- The world finest DVDs for rc soaring pilots. 

New Heading, Denmark 

phone: +45 70 270 620 

email info@newheading.com 

www.newheading.com 

- Wholesaler and importer for Hyperion, APC, Krill 

and many more 

Airmix, Germany 

phone +49/23 03/96 30 46 

email sunline@airmix.de 

www.airmix.de 

- Online-videos to all aspects of modelling. Many 

AUFWIND-review-models are shown here. 

You are a producer, wholesaler, distributor, dealer, 

etc. and you want see your entry on this page? Ask 

for details at advertising@aufwind-magazine.net. 

September/October

Pictorials 

Pilot: Uwe Gewalt 

Model: Schweitzer SGS 2-32 

Location: Wasserkuppe, west slope 


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To be found in AUFWIND at page 16‐17 

Scale glider contest 2008: Uwe had just launched his quarter-scale model of the “Schweitzer SGS 2-32.” The plane 

weighs 7.7 kg and spans 4.3 meters. Uwe himself built it from plans published by Traplet Publications (UK). This 

scale contest always happens at the Wasserkuppe on the last weekend in June. Allowed are models with at least 4 

meters wing span. Besides modern composite planes, always present are beautifully-built vintage gliders. And 

everyone wins if the weather is as nice as it was in 2008: pilots, organizers, spectators, and the photographer. 

Photo: Horst Kretschmer 

Pilot: unknown 

Model: 8-meter “Fox” 

Location: Northern Italy 


A booming day, lift all over the slope, and the face hurts from the sun and the smiles; the pilot is happy! The 8meter 

“Fox” has been the attraction for over 30 minutes; all other pilots have landed to watch the majestic plane. 

The “Fox” whooshes through the air, the wings bend scale-like, energy retention appears endless. After the loop 

follows a long slow roll. It seems the “Fox” defeats gravity. And after the landing, a very content pilot carries his 

plane back to the launch site. A perfect ending of a perfect day! 

Photo: Darius Mahmoudi 

Pilot: Gerald Zauner 

Model: Viking 

Location: Stubwieswipfel (Upper Austria) 


The Stubwieswipfel is popular for ski touring. I had seen it only in winter covered in a thick, snowy blanket. But the 

400-meter high, vertical south wall promised good thermals. Landing conditions are difficult to judge in winter. My 

plan was to have another pilot positioned at the bottom to take over the plane and land it safely. The day came in 

mid-July. A team with everything but the kitchen sink assembled and started the climb carrying all sorts of model 

planes. Landing small planes worked well behind a wall of low-growing larch trees. But there seemed to be no 

thermals; the wind even blew from the north. An Easy Star was volunteered to be the probe. And looky here: a few 

meters off the edge, the little plane was yanked upward fiercely. The question if there was lift had been answered. I 

launched the “Viking” with camera, and for safety reasons, Bernhard landed it down in the valley. 

Photo: Lumix DMC-FX07, 28-mm lens 

September/October

Wood Soars Great 

“Climaxx Compact” by Höllein 

The number of wood kits offered in Germany is quite 

manageable, and there are only a few but active 

manufacturers. I’m happy they exist, because for me 

building is as important as flying, Grüner-CNC, whose 

products are sold by Höllein, is one of these manufactures 

with several planes in its line-up. After the 2007 

release of the 2.5-meter span full-house “Climaxx” (see 

AUFWIND 2/2008), it was obvious that a smaller version 

for the 2-meter class was to be developed to the 

same standards — thus the “Climaxx-Compact” was 

born. 

The first reports all were positive, and I wondered if I 

would agree. I especially was curious if the “Climaxx- 

Compact” would show more energy retention on the 

slope, an attribute its bigger brother was lacking, in my 

opinion. 

I ordered the glider version and an extra electrofuselage, 

which greatly enhances the utility factor. 

Let’s have a look: As with all Grüner-CNC kits, parts 

are sorted by groups and cleanly packed. While a tow 

hook is included this time, still missing are servo covers, 

which I can’t understand, because it’s hard to find 

fitting parts. The RC-Network discussion mentioned a 

mistake in the rib numbering. This mistake was still on 

the plans, but a supplement included in my kit corrected 

this problem. 

As per instructions, I started with the wing halves. 

Each of these has three parts: inner panel, outer panel, 

and winglet. Construction should present no problems 

to the moderately-experienced builder: First, laminate 

the root rib, which is a plywood-balsa-plywood sandwich. 

Then thread the main ribs onto the carbon-tube 

spar and space them according to the plan. Install the 

trailing edge by plugging each rib into the corresponding 

notch, but wait with gluing until later. Fix the wing 

onto the building board with the spar solid on the board 

and the rear end of the ribs resting on the 2-mm strip 

intended for that purpose. A small self-made 90degree 

template helps getting the ribs straight. Now I 

glued the ribs to the spar with as little CA as possible. 

Make sure none of it runs down, because that’d look 

ugly later. Now attach the leading edge, which consists 

of a 2-mm carbon rod. I did this starting at the root rib 

and working my way rib-by-rib outward and again being 

careful not to drip any CA. 

Now, I installed the secondary ribs by wedging them 

between spar and leading edge, and I again carefully 


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glued them with CA. This wing panel was then 

ready to be taken off the board. Now is the time to 

align and glue the trailing edge. The kit contains a 

small template to help with that. Just to be safe, I 

taped off the trailing edge and again worked rib-byrib 

from root to tip. The inner panel was now ready 

for finish gluing. I stood the panel first on its root to 

add CA to one side of each rib-spar joint, then repeated 

the process by standing the panel on its tip. 

Doing it this way prevents CA runs and is accomplished 

quickly and easily. All wing panels were 

built this way. The outer panels additionally needed 

the servo wells installed using the included parts. 

The wing panels are joined by epoxying them together 

with the included fiberglass joiners. I then 

attached the tip blocks and winglets, which resulted 

in me swearing a lot during covering, because the 

wings were now more difficult to handle. When I 

built the big “Climaxx,” I covered the wings before 

attaching the winglets. After gluing the remaining 

reinforcements into the wing, it was time for careful 

sanding in preparation for covering. I prefer transparent 

covering for built-up wings, and I also hinged 

the ailerons with the foil covering. I used Dymond 

“D-60” servos for the ailerons. On the internet I 

found sort-of fitting servo covers, which I painted 

blue, and so it all looks fine now. 

Next we need a fuselage. I had two, electro and 

glider, which differ only in the nose section and the 

fact that the glider fuselage requires more sanding. 

I started by laminating the side panels, aligned 

properly on the plan, which I first covered with clear 

plastic. Now glue on the reinforcements up front 

and the longerons and upright braces in the back. 

The rear reinforcement had to be sanded at an 

angle before installation, so that the fuselage sides 

would fit properly later. Make sure you’re building a 

left and a right half! After the formers and the wing 

mount are glued to the right half, the servo board 

can be plugged in, but don’t glue it yet! This will be 

done after the fuselage is finished and the servos 

are installed. Now the fuselage halves can be 

joined. 

The two fuselages differ in the next step: while the 

electro-fuselage gets just a nose block glued in, the 

glider one requires another former to which the 

nose block gets glued and then sanded to shape. 

Be careful here to assure proper alignment to make 

sure the fuselage remains straight. After the nose 

September/October

section is finished, glue on the tail skid. The instructions 

suggested to install the tail saddle next. I didn’t 

think that was a good idea and deferred this step to 

later. I first installed the push rods and cross braces 

before I glued on the fuselage top and bottom. Now I 

glued the V-tail halves to the tail saddle which I then 

mounted to the fuselage. In my opinion, doing it this 

way has the following advantage: should there be minor 

mistakes, I can now correct them by carefully aligning 

the tail with the wing and the fuselage. Therefore, I 

assure proper geometry. 

I sanded the fuselage to my liking and shaped a pretty 

balsa nose on the glider version. Sanding the electro 

fuselage had to wait for motor installation to be able to 

nicely fair in the spinner. 

I chose to go with Höllein’s recommended drive train. 

Installation was quite interesting, because there wasn’t 

much room left after mounting the “Roxxy 3529-24” 

motor. I was worried that the wires would push through 

the rather thin wall where space for the wires was 

milled out. I proceeded as follows: I pushed the motor 

forward with the cables on the bottom. This forced the 

motor all the way to the top. I then wedged in 1.5-mm 

plywood pieces above and on both sides of the motor, 

which centered the motor in the nose. Now I placed the 

motor mount onto the nose and bolted the motor to it. I 

then tacked on the mount with a little CA. After removing 

the motor, I finish-glued the motor by running CA 

into the joints from the inside and out. Now I reinstalled 

the motor, which is easier said than done, and 

mounted the spinner. After taping off the spinner, I 

carefully shaped the fuselage to match the spinner 

contours. After removing the motor again, I finishsanded 

the whole fuselage. 

I then cleaned to fuselage with silicone remover before 

painting the fuselage with primer and dope. I do this, 

because I almost always cover wooden fuselages with 

Data 

“Climaxx Compact” by Höllein 

An all-wood model for soaring and electric power 

Wing Span: 2.000 mm 

Length: 1.100 mm 

Weight: 885 g (Electro) 

690 g (Glider) 

Area: 33 qdm 

Wing Loading: 26,82 g/qdm (Electro) 

20,91 g/qdm (Glider) 

Airfoil: S-7012 


- 10 - 


Koverall. I then added three coats of a mix of talc 

powder and dope, and sanded the fuselage with 

600-grit paper between each coat. Finally, the fuselage 

got two coats of paint. Sure, that sounds like a 

lot of work for such a simple glider, but the result is 

excellent. 

After the tails were covered, I finished RCinstallation 

and shoe-horned the motor back in. I 

used Graupner “C-261” servos for the tail, as recommended 

by Höllein. No lead was needed to balance 

the electro-version, but the glider needed 120 

grams of nose weight. 

Now it was time to wait until the weather finally and 

suddenly improved sufficiently for a maiden flight. 

The wind was wrong for the slope, so I first took the 

electro version to the flying field. Drivecalc yielded 

991 grams of thrust with Höllein’s setup (Aeronaut 

11x6 prop and 2s LiPo), plenty for a model which 

weighs 885 grams all up. After the obligatory range 

test, I launched the plane, and as expected, it 

climbed to altitude easily. Motor off — and what’s 

that? — the plane mushed around and needed lots 

of down-trim. OK, land immediately and add nose 

weight. I had to repeat this three times and added a 

total of 104 g of lead to the nose. But then the plane 

flew nice and stable. During the following weeks, I 

flew the “Climaxx Compact” several times on the 

slope also, which was a lot of fun. 

Meanwhile, I have about 20 hours on the plane, and 

my verdict is quite positive: the “Climaxx Compact” 

is easy to fly and responds well to lift. I mostly fly 

the electro version, because if there is no slope lift, 

there are almost always thermals, particularly 

higher up: 20 seconds of motor run yield 70 minutes 

of flying time. 

Stephan Siemund 

Price: 135 Euros at Höllein, Germany, Tel. +49/9561/555999, www.hoelleinshop.de. 

September/October

Photo Captions: 

Page 22: 

- 2-meter (electro) gliders are always popular. 

- Covered in attractive colors, even a “wood crate” looks modern. 

Page 23: 

- Thanks to perfectly-fitting parts, building the wing is a breeze. 

- The glider nose is shaped from a solid chunk of wood. 

Page 24: 

- Make sure to build the fuselage precisely and straight. 

- In the electro version, the motor mount is simply glued to a small balsa block. 

- The “Climaxx” sisters: full-house “Climaxx” on the left, new “Climaxx-Compact” on the right. 


- 11 - 


___________________________________________________________________________________________ 

www.shredair.com 

___________________________________________________________________________________________ 

September/October

Electro‐Eagle 

“F3B-Eagle” by Jiri Tuma 

As a dyed-in-the-wool slope head, eagle encounters 

are nothing new to me. Quite a few times, I‘ve been 

lucky enough to be allowed to join these majestic birds 

in thermals. Such encounters are some of the nicest 

experiences in my life as a model pilot. A particular 

specimen of this type recently found its way into my 

shop: it is the “Eagle” by Austrian designer Günther 

Aichholzer. This model — like its successor, the “Evolution” 

— is manufactured by Jiri Tuma in the Czech 

Republic. Contrary to its intent as a pure-bred F3B or 

F3F competition plane, I wanted to convert it into an 

electric-powered fun flyer. 

The all-molded model is available with glass/glass 

wings, carbon/glass wing, or double-carbon wings. 1.2mm 

Herex is used as the sandwich material. After talking 

with the designer Günther Aichholzer, I ordered the 

carbon/glass version with UMS spar and cross-tail. As 

an option, my “Eagle” came equipped with RDS (Rotary 

Drive System; see Aufwind 5/2009) on the ailerons 

and flaps. The optional Kevlar nose makes the plane 

2.4-GHz friendly. After three months of joyful anticipation, 

my custom-made model arrived. 

During the initial drooling over this eagle chick, I noticed 

the narrow fuselage with its hardly noticeable 

seam line and perfectly fitting nose cone. I immediately 

liked the high strength and low weight. Rudder linkage 

and wiper were factory installed, as was the completely 

slop-free linkage for the full-flying stabilizer. Also the 

opening for the wing joiner was ready to go. The construction 

and quality of the wings is admirable: flaps 

and ailerons are bottom-hinged with wipers on top. 

Herex ribs in the wings really increase torsional stiffness. 

The RDS pockets also came factory-installed 

and were ready to go; of course, all parts for the RDS 

system were included. The horizontal stabilizer was 

nice and light and included a 6-mm carbon joiner. The 

surface and paint quality matched today’s F3B standards. 

The parts weights were: 

Fuselage with Nose Cone 456 g 

Left Wing 550 g 

Right Wing 540 g 

Wing Joiner 112 g 

Stabilizer 57 g 

Because Jiri Tuma does not manufacture an electrofuselage 

for the Eagle, I started my assembly by modifying 

the fuselage. I wanted to install the motor into the 

nose cone, and place the rudder and elevator servos 


- 12 - 



along with the receiver behind the wing joiner. I 

masked off the fuselage, marked the opening, and 

cut it out with a cutting wheel. After installing a motor 

mount in the nose cone and bolting on the motor 

with controller, I quickly had an easy-to-assemble 

electro-fuselage. I chose a Hacker “B50-12S” with 

6.7:1 planetary gearbox and a Kontronik “Jazz 80- 

6-18 BEC” controller. The propeller is a 17x11 

folder by Aeronaut. This drive train is powered by a 

4s “Polyquest” LiPo battery with 3,700 mAh capacity. 

After installing the elevator and rudder servos 

(Futaba “S3150” and Graupner “DS-362” respectively) 

and the receiver (Futaba “R6008”), the fuselage 

was finished. 

On to the RDS installation in the wings: First, I 

treated the servos (Futaba “S3150”) with release 

agent and made molds of the output gears using 

“UHU-plus endfest 300.” Now I bolted the servos 

into their frames, which I purchased from RC Solutions 

(www.rcsolutions.ch). During installation, it’s 

important to assure that the bent shaft gets centered 

in the pocket. After the correct position is 

marked, the servo frames and short brass guides 

can be glued in. The bent shaft has to be thoroughly 

sanded and degreased before glueing. Also 

make sure that the bend is in line with the hinge. 

This is accomplished by applying resin to the steel 

shaft and aluminum part, then mount the linkage. 

The grub screw in the alu-part has to be up, of 

course. Move the control surface up and down a 

few times to center the shaft, then tape the control 

surface and let everything cure. More info and photos 

about this RDS system are at Jiri Tuma’s page 

(www.jitom.com). The model can also be ordered 

with RDS completely installed. 

After finishing the wings the programming can begin. 

I use three modes, “Thermal,” “Normal,” and 

“Speed.” For the last two , I mix flaps with ailerons. I 

set the CG at 92 millimeters. After setting the decalage 

at the elevator, I headed to the flying field for 

the maiden flight and assembled the “Eagle” with 

much anticipation. Field assembly is simple: plug-in 

and tape wings, plug in stab, install and secure 

battery, install and secure nose cone. 

A quick range check, then launch: The “Eagle” flew 

briskly out of my hand. I flew the plane to safety 

altitude and started to check it out. It showed much 

promise: it thermaled nice and slow and with wings 

September/October

almost level; it showed no tendency to stall. A hawk 

joined us and together we enjoyed the flight. 

But a F3B/F3F plane also has a high gear. Set flight 

mode switch to “Speed” and push elevator stick forward. 

The “Eagle” lowered the nose and came down 

400 meters quietly whistling across the field. I flew 

three full circles without noticing any wing bend and 

powered up again. Now some more aerobatics: rolls, 

loops, and inverted flight. My subjective feeling is that 

the plane is very quiet at speed and maintains momentum 

quite well. This, in my opinion, is directly attributable 

to the airfoil and the RDS system and the resulting 

“clean” wings. I’m a happy camper! 

Data 

“Eagle” by Jiri Tuma 

An electric-powered high-performance plane 



Weight: 2.651 g 

Wing Loading: 41,50 g/dm² 

Airfoil: HQ mod. 1,8/7,5 

Motor: „B50-12S“ 6,7:1, Hacker 

Controller: „Jazz 80-6-18 BEC“, Kontronik 

Battery: 4s-LiPo 3.700 mAh 

Propeller: Aeronaut CAM Carbon 17x11“ 



- 13 - 


After 5 minutes of motor run time and 56 minutes 

total flying time, I landed at walking speed. Back in 

the shop, I measured the battery to find out I had 

used 3300 mAh. Thus, my estimates were right on, 

and I can look forward to many more flights. The 

”Eagle” by Jiri Tuma shows great flying characteristics 

and follows pilot commands willingly. It circles 

with the best, yet is plenty strong for brutal speed 

runs. Jiri deserves praise, because the all-up weight 

of a mere 2,651 grams shows expert application of 

resin and cloth. The model and I have been getting 

along well from first launch. With this “Eagle,” my 

dream of a spirited fun and leisure flyer came true; 

from field to alpine slope. 

Reinhard Hafele 

Control Throws: 

Aileron -10/+4 mm 

Flap Camber -5 mm 

Elevator +/-9 mm 

Rudder +/-15 mm 

Thermal Mode: 

Aileron: +4 mm 

Flaps: +4 mm 

Speed Mode: 

Aileron: -2 mm 

Flaps: -2 mm 

Elevator: -1 mm 

Crow: 


Flaps: +38 mm 

Elevator: -3 mm 

Page 26: 

- Electrifying the “Eagle” resulted in a high-performance model for every-day use. 

Page 27: 

- The flying characteristics are without fault. 

Price: 1.040,- Euro; Info: www.jitom.com 

Page 28: 

- Motor and controller are mounted in the nose cone. Elevator and rudder servos and the receiver sit behind the 

wing joiner. 

- Comparison between my modified electro-fuselage (below) with the original glider fuselage. 

- Finished aileron installation with RDS. 

- Thanks to the removable nose cone, battery change is quick and easy in the field. 

- The paint scheme on the wing bottom assures optimal visibility. 

- At full crow, the “Eagle” lands at walking speed. 

September/October

Electric Duo 

“Twin Otter” by Lindinger 

The number of multi-motor electric models appears to 

be declining. Is it because the effort seems too high, 

due to today’s brushless motors requiring a controller 

each? Or is it the long cables which can make motors 

run capriciously? In the days of brushed motors, we 

could run several motors on one appropriately-sized 

controller. Maybe a controller manufacturer could be 

talked into developing a controller with one battery 

connection and several motor connections? Such a 

thing existed in the days of brushed motors. 

But multi-motor (electric-powered) models always have 

been particularly fascinating to modelers. That’s why 

Lindinger in Austria deserves praise for importing the 

“Twin Otter” from the Far-East manufacturer Planet 

Hobby. To reveal the result right now: This 165-cmspan 

plane is easy to fly, inexpensive to power, and kit 

quality and prefabrication and cost is such that the 

spread of multi-motor electric models is virtually guaranteed. 

But let’s start at the beginning: the “Twin Otter” comes 

built and covered. The fiberglass parts are pre-painted 

in multiple colors, and the small parts are of useful 

quality and packed in “countless” little bags. There are 

many vacuum-formed parts, especially for the engine 

pods and the wheel pants. The instructions mostly are 

little photos and drawings. Completing the model requires 

mostly bolting parts together and soldering. All 

that went well. I used “HS-225” servos by Hitec/Multiplex. 

These are robust and inexpensive and 

not too heavy – Ideal for this type of model. 

Just one thing I disliked on the “Twin Otter:” wings and 

stabilizer came covered in black. The stab is only 5 

mm thick. Such parts will warp in the sun! How much 

so, I didn’t want to find out, so I removed the black stuff 

and replaced it with dark-red “Orastick” covering. This 

color matched the one on the fuselage perfectly. While 

removing the black covering, I noticed that it really was 

a semi-transparent matte foil which was painted. An 

unconventional but practical solution. OK, let’s assemble 

the plane. But what the heck? The aluminum wing 

joiner is way too big to fit into the fuselage. After hours 

of work with a round file, I finally hammered the thing in 

with a wooden mallet – never to be removed again. 

I chose Lindinger’s inexpensive “X-Power Eco A2814- 

08” motors and two 40-A-BEC controllers by Jamara 

for this model. The controllers sit side-by-side in the 

fuselage and are connected to the receiver with a V- 


- 14 - 



cable. To hook up the motors in the wing to the 

controllers in the fuselage, I used Multiplex 6-pin 

connectors, which means I combined two gold pins 

per motor phase. During the first motor test runs, 

the controllers got very hot very fast. Obviously the 

two BEC systems didn’t like one-another. So I disabled 

one BEC by pulling the red wire from the 

receiver plug, and everything has been working 

perfectly ever since. For a battery, I chose a 3s 

LiPo pack with 3,300 mAh capacity. This pack is 

fastened with hook and loop fasteners as far forward 

in the fuselage as it will go, and the CG 

hereby perfectly matched the instructions. 

And suddenly, somehow, the pretty “Twin Otter” 

was finished. Time for the maiden flight on one of 

the first nice days of summer. Little power sufficed 

to taxi the plane to the take-off position; the steerable 

nose-wheel made it track like a model train. 

Point the nose into the wind and slowly apply full 

power. The “Twin Otter” accelerated smartly and 

lifted off by itself with slightly raised nose wheel. It 

was solid in the air and climbed smoothly to altitude. 

And just as smoothly, it flew the pattern 

around the field. A little more than half-throttle sufficed 

to putt around the sky. I only missed one 

thing: the sound of a twin. Obviously the two motors 

ran in complete sync and their sound was at exactly 

the same pitch. During low passes — coming in at 

part-throttle, then climb out at full throttle — the 

model is a sight to behold. Full-on curves, loops, 

and rolls are absolutely no problem. Just like the 

landings: throttle back, wings level, flare, and the 

“Twin Otter” placidly touches down and hobbles to a 

stop. Multi-motor flying can be this simple and attractive! 

Many more flights happened in weeks to follow and 

in all kinds of weather. This twin really hates strong 

wind — it bucks around the sky and drifts sideways 

in cross wind, but all that is quite controllable. It just 

looks bad. It simply is nicest to fly the “Twin Otter” 

scale-like at part throttle across the field. And exactly 

that is what this model is made for. 

Egon Becker was happy to film this model. His 

video is can be found under www.airmix.de. 

Philipp Gardemin 

September/October


- 15 - 


About the Original 

The DHC-6 Twin Otter is an ASTOL plane by the Canadian manufacturer De Havilland. It seats 20 people and has 

a 19.8-meter span. It’s designed for extremely short take-off and landing, and a 366-meter runway suffices. The 

plane first flew in May 1965, and 844 were built. Production stopped in 1988, but is said to start up again this year 

at Viking Air. A sad incidence with a Twin Otter happened in October 2008, when one crashed during landing in 

Lukla, Nepal. Eighteen people died. 

Data 

“Twin Otter” by Lindinger 

An Electro-Twin 



Weight: 1.950 g 

Motors: X-Power Eco A2814-08 

Propellers: 8x4“ APC-E 

Battery: 3s-LiPo 3.300 mAh 

Price: 199,- Euro; available at Lindinger, Austria, tel. +43/7584/3318-0, www.lindinger.at. 


Page 30: 

- Still compact at 1,650 mm span, the pretty “Twin Otter” is an every-day flyer. 

- The plane looks fascinating in the air and has that certain scale-like portliness. Photo: David Waltenberger 

- Countless vacuum-formed parts, such as engine pods and wheel pants, help the model’s scale looks. 

Page 31: 

- The black covering was replaced with red foil on top of the wing and stab. 

- Special spacers for mounting the motors were included in the kit. 

- The battery is accessible easily by removing the fuselage lid. 

- Egon Becker of Airmix made a great video of this nice model. 

- The original in this livery is operated by Kenn Borek Air, Ltd. It’s used for supply flights in arctic regions. Photo: 

Airliners.net, Chris Ettinger 

September/October

Retroplane 2009 

Vintage Gliders over Ireland! 

I was smiling to myself while reading the opening 

paragraph about Retroplane 2008 in AUFWIND 

1/2009. We picked the 2008 site, because the event 

had been plagued by rain in previous years, yet this 

criterium certainly was neglected during selection of 

the 2009 site. Otherwise, notoriously rainy Ireland 

never would have been up for discussion. Fred Marie, 

a French expatriate who lives in Ireland, and the club 

“Island Slope Rebels” he and Joe Doyle founded, had 

offered to host a Retroplane meet. A few Retroplane 

pilots flew to Ireland to check out the site (see 

AUFWIND 6/2008). They reported an ideal slope soaring 

area with slopes facing almost all directions and 

with thermal and slope lift in abundance. 

So the decision was made: Mount Leinster in Ireland 

will be the site of Retroplane 2009. Pre-registration 

was opened, and we had to register right quick, because 

the cut-off of 70 participants was approaching 

fast. It was clear, however, that for many registrants 

this was more of a dream than deliberate planning; in 

the end only 25 participants made it to Ireland. 

Most combined the Retroplane meet with a family vacation. 

So it was for me and many others. We started 

Sunday, July 5th, drove to Dunkirk, took the ferry to 

Dover, and drove through England to Pembroke. 

There, we joined up with the Belgian contingent: Mark 

Bruylants and Kristof Frotemps had booked the same 

ferry to Rosslare. We arrived at the campground Morriscastle 

on Monday night. By that time, the base-camp 

Retroplane was almost complete already. The campground 

is near Kilmuckridge in Waxford County about 

100 km south of Dublin. The Mount Leinster flying site 

is about 45 minutes west of here farther inland. 

The welcoming by Fred’s Club ISR was exemplary, 

including Joe and his wife Clair, who served us food 

and drink throughout the weekend. The Irish Model 

Association sponsored the event, and so the small club 

not only could offer all meals for free, we also received 

an insurance card which was valid throughout Ireland 

for the length of our stay. Joe also acted as our vacation 

planner and personal weather forecaster, who 

always delivered the latest updates. Wednesday night, 

he forecast a good westerly flow and few clouds for 

Thursday, while for the following days had rain in the 

forecast. Without further ado, we moved the start of the 

event up by one day. Pilots not staying at the campground 

were notified by phone. On Thursday, July 8, 

off we went to the west slope of Mount Leinster. This 


- 16 - 



was convenient, because the parking area is right 

next to the slope, and the planes do not have to be 

carried very far. The slope itself is huge. Landing is 

no problem; one LZ is a carpet of heather, which 

sometimes interferes with wing struts; the other is a 

somewhat lumpy grass area. It was overcast in the 

morning, but the sun came out in the afternoon. 

Wind speed was 15-20 km/h, sufficient for all models, 

even the biggest ones. Occasionally, the wind 

did die down a bit and a few pilots had to land out 

— luckily without damage. 

It’s become a tradition to bring new models straight 

out of the shop to the event. This year, there were 

17 of them. Many participant had followed progress 

on these models in the on-line Retroplane forum 

and now were curious to see them live and in color. 

The most conspicuous and original designs were by 

Claude Lacombe and Laurent Legeay: both were 

modeling the RRG Ente, Claude in 5th-scale and 

Laurent in quarter-scale. Each chose his own 

method, based on available documentation in the 

museum at the Wasserkuppe. Claude used traditional 

tools with plan and saw, while Lauren drew 

his plan using the latest 3D-CAD computer software. 

He included every detail to build the model 

practically like the original with straps and struts. He 

used 3x3 and 2x2 mm pine strips and thousands of 

triangles made from 0.4-mm plywood. Excellent 

work, which I reported on in the Retroplane column 

in AUFWIND 3/2009. 

Also present was a “Harbinger” by Michele Malabat; 

Fred Marie’s “Ka-1,” sheeted in plywood with a 

clear coat finish; the “Backtroms” by Roland Hänel, 

Alain Lafon and Ronan Plu; a “Ka-8” by Benoit 

Baradon; the “Minimoa” by Marc-Andre Barras; the 

“Doppel-Raab” by Marc Bruylants; the little 

“Slingsby Petrel” by Laurent Caralp; the beautiful 

“Horten XVI Colibri” by Lothar Mentz; and the “Ka- 

3” by Jean-Claude Souchard. But also the “Musger 

MG9a” by Vincent “Mr. Retroplane” Besancon performed 

its maiden flight. 

The Irish surprised us with two “Opel Rak” by Ralph 

MacCarthy and Les Gosnell. The president of the 

Irish Model Association, Kevin Barry, brought a 

“Musger Mg-19B” and a “SZD-6 Nietoprez.” 

September/October

Everyone, of course, was waiting for the maiden flights 

of the RRG canards and the “Horten Colibri,” because 

they were very different from conventional aircraft. 

Laurent Legay was the first to step up to the slope 

edge. After the umpteenth control check and a discussion 

about the center of gravity, Erwan Plu launched 

the plane. Unfortunately, it did not do as its builder had 

planned: it immediately went into a dive, and no 

amount of up-elevator could alter its course. Gladly, 

there was damage only to the pylon for the stabilizer. 

We surmised that launch speed was too low; more 

wind might have helped. But mostly we think the CG 

was way off. The problem is, there is only very vague 

information available on this subject. Despite earlier 

tests, Claude’s RRG suffered the same fate. We’re 

sure that the cause is the same in both planes, and 

both designers will have to stick their heads together to 

figure it out. Lothar Mentz also had to fight with the CG 

of his “Horten Colibri.” He had just barely finished the 

scale center section of the plane for the meet, but had 

flown the wings with an experimental center piece. He 

thinks, he underestimated the effect of the large scale 

canopy. The model did fly but needed so much upelevator 

trim that there was almost no more aileron 

response. But Lothar was able to land the plane a 

ways down the slope without damage. Other maiden 

flights went off without a hitch. And when we packed it 

in for the day, we were happy to report only minor 

damage, nothing important. 

At the campground, we were treated to beautiful evening 

light and the traditional display of fuselages. At 

the same time, the extensive aperitif was prepared, 

and everyone contributed with specialties of their regions. 

At the end of the evening we were treated to — 

what else — a strong rain shower. What can I say? 

The “Irish summer” is ever-present. 

Friday’s forecast called for no wind, and rain starting at 

noon. So, we quickly organized an aero-tow at the 

Ferns model airfield. The Plu brothers had brought 

their tugs for just such a scenario. But the fun didn’t 

last, because the rain arrived a lot sooner than forecast, 

and it stuck around. Saturday was the same: rain, 


- 17 - 


rain, rain. That’s why the raffle was moved up a 

day, and at 10 AM, we assembled at the campground’s 

meeting room. Each participant got a 

Retroplane t-shirt, a Retroplane clock designed by 

Vincent, and the sponsor’s donations were raffled 

off. The best design was awarded the golden 

Retroplane Rib, and it deservedly went to Laurent 

Legay. Because this also was the fifth Retroplane 

meet, all participants who had attended all meets 

were given a wooden plaque with the Retroplane 

logo. 

On Sunday, the weather looked better. According to 

the forecast, it was to be cloudy with some showers 

and sunshine. We went back to Mount Leinster: the 

wind was strong gusting to 50 km/h and the ceiling 

was low. We assembled our planes and walked up 

to the slope. We couldn’t fly at first, because the 

first rain squall arrived right away. We were prepared, 

and models and radios were covered with 

tarps. We did get a bit of flying in during the the sun 

breaks and had logged quite a number of flights by 

evening. I myself made four of them, a Retroplane 

record for me. 

By Monday, the weather had cleared up, but there 

was only a light on-shore breeze, which increased 

in the afternoon. We immediately drove to the 

coast, but by the time we arrived, the wind had 

turned and was blowing parallel to the cliff face. So 

unfortunately, we couldn’t fly, and Retroplane 2009 

was officially over. 

Despite the weather, all participants were happy 

with the event. In fact, Retroplane 2009 was declared 

the best one yet, because — paradoxically 

— it had seen the most flying, despite the “Irish 

summer.” A big thank you goes to our hosts, particularly 

Fred Marie and Joe Doyle and their wives. 

And of course to Vincent and Joelle Besancon, 

without whom the Retroplane meet wouldn’t exist. 

Stephan Siemund 

Photos: Retroplane participants 

___________________________________________________________________________________________ 

www.retroplane.net 

___________________________________________________________________________________________ 

September/October


Page 32: 

- Group photo of the Retroplane 2009 participants. 

- The traditional fuselage exhibit in the evening light at the campground. 


- 18 - 


Page 33: 

- The new “Ka-8” by Benoit Barradon, built after a plan by Gerard Risbourg and enlarged to 3 meters span. The 

paint job matches the full-size one of the French Falaise aero-club. 

- The “Musger MG-19b” by Kevin Barry, president of the Irish Model Association, just got finished in time for the 

event. 

- The big “Harbinger” by Bernard Kluijtmans flew without wing struts to prevent possible damage on landing. 

- It looks like she’s a-flyin’: the canard by Laurent Legeay. Unfortunately, it shared its fate with the one by Claude 

Lacombe: barely launched, both went into a dive. 

- Also by Laurent Legeay is this beautiful model of a “Zlin 24 Krajanek” in 4.3rd-scale (3 meters wing span). The 

fuselage and wings are sheeted in cherry veneer. 

- Lothar Menz with his 3rd-scale “Horten XVI Colibri.” Lothar drew his own plans. 

Page 34: 

- A low pass of Ronan Plu’s “Slingsby T31” in Air Cadet livery. At 3.5-scale, the plane has 3.8 meters span, and it 

built after a plan by Pierre Delrieu. 

- Jean-Marie Mesot unfortunately could not finish his model on time, but came anyway to show the “Moswey 3” in 

its current state of completion. It’s his own design based on a 3-view drawing. 

- The golden Retroplane-Rib 2009 was awarded to Laurent Legeay for his unusual design of the 1928 RRG Ente. 

- The Author’s “Musger MG-19b” on final approach. This model logged quite a few hours during this event. 

- Another unusual model is this quarter-scale ”Musger MG-9a” by Retroplane founder Vincent Besancon. 

- The ”Fauvel AV-361 hadn’t flown since the meet at Schweisel. Unfortunately, the fuselage broke during a hard 

landing. 

- One of three “Opel Rak.” This one is Irish-man Les Gosnell’s model. This glider needs a bit of lift to stay up. 

Page 35: 

- Alexander Spörl’s quarter-scale “Grunau Baby II” is built from a Krick kit. 

- This “Ka-1” with plywood finish by Fred Marie had a successful maiden flight at the meet. 

- Armand Giraud’s “Grunau Baby II” flew into a rotor on landing, but was only lightly damaged. 

___________________________________________________________________________________________ 

www.gliderireland.net 

___________________________________________________________________________________________ 

September/October

SAL‐RC‐HLG 

Or: What Might the Future Look Like? 

In the late ‘90s at the end of the “Tercel” era, I considered 

building my first HLG. Back then, the wings for 

these planes had a relatively low aspect ratio, were 

build with foam cores and balsa sheeting, the popular 

airfoil was the “SD-3021,” and one minute of flying time 

was very good for average HLG pilots. I launched my 

models on a bungee, or I flew them on a small slope; 

rarely did I hand-launch them competition-style, because 

I lacked the athletic ability needed for contests. 

Applying my professional background, I built the first 

molded wings in 1993. These had higher aspect ratios 

and the fashionable double-taper, and I used the “RG- 

15” or 7% “Gö-795” airfoils. They did perform well, but 

unfortunately were a bit heavy. 

During my 10 years of absence it became obvious that 

many free-flight building techniques had found their 

way into the HLG scene: the carbon fiber D-box, for 

example. Meanwhile, that technique has been replaced 

by the next generation of glass/carbon foam 

sandwich wings. And due to the SAL technique, models 

were now equipped with flaperons. They also 

started looking a bit more like F3B and F3J planes, 

although this was not necessary, as demonstrated by 

Mark Drela’s “Apogee” series. 

Since the SAL technique matured, performance has 

been unchanged more or less, even though athletic 

pilots can throw higher than 50 meters and are pushing 

2 minutes of dead-air hang time. Power and technique 

are deciding factors; add to that a good feel for lift, and 

you’ll be a serious competitor. 

So for the next round of innovations, we need to find 

new ways. If we look at the development of free-flight 

HLGs, we’ll see that today’s popular thin airfoils by 

Mark Drela are based on these. They have 5% thickness 

and sharp leading edges, and most significantly a 

convex underside for the front third of the airfoil to help 

during the rapid ascent. Mark Drela used to be a successful 

free-flight HLG competitor, who experimented 

with so-called flapper airfoils (see sketch 1). 

The models looked similar to the “Apogee” series, aesthetically 

pleasing with an elliptical planform. Indoors 

and with a normal launch, Mark Drela had flights up to 

94 seconds long, his colleague Stan Stoy even 

reached 109 seconds with a similar model. The airfoil 

had a bit of camber while gliding, but during the climbout, 

the rear part is flapped up about 45 percent, so 


- 19 - 



that the airfoil is quite flat. By the way, these models 

with a wing span of up to 500 millimeters weigh only 

about 6 grams! 

Free-flight models of the international F1A class 

have undergone a similar development: they have 

polyhedral flapper wings with up to 2.4 meters wing 

span. The front and the rear halves of the airfoil 

rotate around a fixed point to maintain a decalage 

setting. The airfoils are flapped during launch, only 

to be fully cambered again while gliding (see sketch 

2). For the various flight phases, different decalages 

for straight and curving glide are set using a laptopprogramable 

timer — a quite involved affair. But 80meter 

heights have been reached with 50 meters of 

line, and 90 meters are a realistic goal. 

This flap apparatus would be easier to implement in 

a RC glider. But there is one serious problem: the 

flapped rear part of the airfoil is useless as an aileron. 

So, separate flaps have to fill this need, possibly 

built into the movable part of the airfoil, or (and 

why not?) in a large, high-aspect-ratio V-tail set at a 

large opening angle and a fin below to compensate 

for yaw. We see this configuration already used in 

free-flight SAL HLGs. 

Flappers are one possibility, but there are others. 

So we get to the folders: I’ve been fascinated with 

this idea since I experimented with free-flight catapult 

gliders and the folding flying wing “50-Cent- 

Wing.” Why not reduce wetted area by folding the 

wing? At first I thought of a similar flying wing which 

is launched folded. I ballasted such a model to keep 

the center of gravity near the hinge during folded 

launch. Half of the launches were successful, but as 

soon as the wind came up, I had problems. Tightly 

folded wings make SAL flying safer. Washed-out 

wing tips add stability much like the vanes on an 

arrow. Maybe additional stabilizing flaps would help. 

For now, I’ve put this concept aside. 

In the ‘80s, US indoor free-flight HLG specialist 

Stan Stoy experimented successfully with doublefolders 

(see sketch 3). When folded, the outer wing 

panels are sandwiched between the two inner ones. 

The idea is simple: rubber bands open the wing, the 

panels of which are hinged with tape. The release 

mechanism also is quite nifty: a rubber-band controlled 

clip releases the wing at the end of the climb. 

September/October

After building 6 prototypes, Stan flew a US record of 83 

seconds in a 25-meter hall in 1979! 

Possibly, this design inspired the russian mechanics 

professor Leonid Fuzeyev to develop a double-folder 

for the motor free-flight class F1C, with which he became 

world champion in 2003 and European champion 

in 2005. His plane reached 160 meters in altitude 

instead of the normal 130 meters during the 4.8second 

climb. Given linear acceleration (max velocity 

is reached in 5 seconds) his plane exceeded 200 km/h 

going almost straight up. By comparison, the “Ariane” 

rocket climbs a lot slower during its initial launch 

phase. 

The Titanium hinges are simple but ingenious. Eight 

rubber bands made from high-performance free-flight 

rubber open the wing with about five to ten kiloponds 

of pull. Clever is the fact that the rubber bands also act 

as shock absorbers because the wing panels can 

move past their normal stops. Sketch 4 shows the 

model with its airfoils. 


- 20 - 


I don’t imagine RC-SAL-HLG of the future to be this 

sophisticated. It should be a simple folder which is 

launched with a symmetrical airfoil, but floats on a 

high-lift airfoil after opening. Different airfoils can be 

used for different wind conditions. Opening the wing 

with RC is quite simple. Instead of ailerons, the 

plane will have a rather flat V-tail with a sub fin beneath. 

I’m currently building prototypes of the folding 

mechanism, and there is still a lot to be figured 

out. Even though the outer panels of my 1.2-meter 

span test model weigh only 20 grams, there are 

significant forces to be dealt with during the opening 

stage. The wing is built without ribs from solid balsa 

(see sketch 4). 

For anyone interested, I have available copies of 

articles about the indoor folder and the F1C model, 

which appeared in the US magazine “Free Flight 

Quarterly.” 

Hans Baier 

September/October

Scale‐Glider News 

News from the Scale-Glider Scene 


- 21 - 



Note: the German “Großsegler” literally translates to “large glider.” However, with a few exceptions, Großsegler 

typically means scale-glider. So for the purpose of these translations, I’ll be translating Großsegler as scale-glider, 

and I’ll identify purpose-designed models as needed. 

HKM Scale-Glider Meet 

In late June, the Rheydter Flugmodell Club (RFMC) 

held its annual meet for fans of scale gliders at its flying 

site near Mönchengladbach. This event, organized 

by HKM owner Willi Helpenstein and RFMC, is one of 

the season highlights for the scale-glider community. 

Despite uncertain weather, more than 75 pilots were 

present at Saturday morning’s pilots’ meeting. The 

weather held, and flying started around 10 AM. There 

were plenty of tow planes, and they worked seamlessly 

to minimize waiting time for the glider pilots. Much 

anticipated again was the raffle of an all-molded “ASW- 

27” donated by HKM. The lucky winner this year was 

Jürgen Stutz from Baden-Württemberg. The organizers 

deserve much praise for an all around successful firstclass 

event. 

Erwin Schreiber 

Scale-Gliders in Weilheim 

In early August, the Modellfluggruppe Weilheim in 

southern Bavaria held its 10th annual event. Glorious 

sunshine greeted 70 participants from Germany, Austria, 

Switzerland, Italy, and the Netherlands on Saturday. 

Numerous tugs towed the gliders to altitude efficiently, 

and together with several gliders equipped with 

self-launch systems, they used the great summer 

weather for extensive flights. Of special note was the 

electric-powered tow plane “Rally Morane” by Georg 

Thanner. With a 4-meter wing span, it proved its usefulness 

at this event. There were some outstanding 

gliders also, both in regards to size and technical 

equipment. 

Dieter Keipinger 

Tradition in Giengen 

Excellent weather caused optimal conditions for the 

24th Thermikpokal of the Modellflugsportverein Giengen. 

Almost 20 competitors from southern Germany 

took part. Planes had to be winch-launched and perform 

four 30-minute flights. Landing was scored on a 

landing field with the center having the highest score. 

Because thermals were frequent and sometimes large, 

most pilots made their times. However, landing was 

made difficult due to a sometimes gusty cross-wind. 

Gerald Reischl won the purpose-designed-models 

class (min. 3.5-meter span). He also had the highest 

score overall, and so he keeps the trophy for 

one year. In the semi-scale and scale class (quarter-scale 

on up), Ralph Mittelbach repeated his win 

from last year. For next year’s 25th anniversary, 

organizers plan a different program, which likely will 

replace winch-launching with aero-tow. 

Scale Glider from Kärnten 

Markus Egger from Feldkirchen (Kärnten, Austria) 

just introduced a third-scale model of the new 2seater 

“Arcus” (wing span 6.66 m). The kit has a 

white fiber-glass fuselage and a 4-piece wing made 

from obeche-sheeted styrofoam. Spoilers are installed 

and capped, and the wing has HQ-DS transitioning 

airfoils. The fiberglass leading edge is 

attached, and wing and stab are sanded ready-tocover. 

The control surfaces are cut out and finished. 

A cockpit kit is available as an option, as are carbonfiber-reinforced 

wings. Flying weight is about 14 

kg, and prices start at 1,950 Euros. Besides the 

new “Arcus,” Markus Egger also offers other interesting 

scale gliders: “ASW-15B” (1:2 and 1:3), “DG- 

1000” (1:3), “DG-303 Acro” (1:2.5), “Duo-Discus” 

(1:3 and 1:3.3), “ASG-29” (1:2 and 1:3), “ASW-28” 

(1:2 and 1:3), and Fox (1:2.8). In addition, scratchbuilders 

can order CNC-cut wing cores. 

www.modellbau-egger.at 

“Ventus-2cx” by Wemo- 

Composite 

This new model in 1:2.4 scale has been available 

since early June. CEO Gerold Werner offers the 

following details for this 7.5-meter span, all-molded 

scale glider: flying weight is about 20 kg, and the 

wings with massive joiner box are reinforced with 

bi-axial carbon cloth. The full-length spar contains 

about 650 meters of carbon rovings. Wheel well, 

landing gear formers, and those for battery and RC 

components are factory installed, as is the elevator 

servo. All control surfaces come skin-hinged as 

“elastic-flaps.” Spoilers are installed and capped. 

Included is a landing gear with suspension and 

brake, a tow release, and a clear canopy with 

frame. Price is 4,400 Euros. A ready-to-fly version 

September/October

is an option. Available at Wemo-composite Gerold 

Werner, tel. +49/7385/303644, email wemocomposite@t-online.de. 

HB-Modellbau News 

Adding to his successful “SZD-59 Acro,” Heiko Baumgärtner 

now offers another large scale-glider: The “Arcus” 

2-seater in third-scale with 6.66 meters wing 

span. The wings have airfoils transitioning from HQ to 

HB. Flying weight, including scale cockpit, two scale 

pilots, 14 servos, and suspension landing gear is about 

15 kg. Wing loading ranges from 87 to 95 g/sqdm. The 

“Arcus” is designed for a speed of 200 km/h and has a 

carbon-sandwich spar with carbonfiber-reinforced obeche-sheeted 

wings. The highly-accurate wings are 

pressed in a special mold, according to Heiko Baumgärtner. 

Winglets and outer wing panels are removable 

for transport. All control surfaces are hinged as knuckle 

joints in carbon fiber tubes. The carbon fiber joiner 

measures 30x30 millimeters in cross-section. Available 

at HB-Modellbau, tel. +49/365/7115994, 

www.hb-modellbau.de. 

New Full-Size Gliders 

This year, we were surprised by several new full-size 

gliders. After the “Arcus” 2-seater by Schempp-Hirth 

and the 21-meter “ASH-31” by Schleicher, another 

plane premiered in July: The “Nimeta” is the personal 

dream of successful competition pilot and 1989 world 

champ in the 15-meter racing class Bruno Gantenbrink. 

This 31-meter, single-seat glider combines a 

modified “Nimbus 4M” fuselage with the wings of the 

“eta.” The “Nimeta” was built by Glasfaser-Flugzeug- 

Service Hansjörg Streifeneder (www.streifly.de). Most 

challenging was the fitting and connecting of the differ- 



- 22 - 


ent linkage systems in the fuselage and the wings. 

Also new is the self-launch-capable 2-seater “EB 28 

Edition” by Binder Flugmotoren- und Flugzeugbau 

in Ostheim (www.binder-flugmotorenbau.de) with 

enlarged and optimized outer panels. These panels 

have new winglets and a thinner airfoil with less 

drag. The wing area of this most modern openclass 

2-seater with a 28.3 meter span is hereby 

reduced by about 0.3 square meters. This results in 

a higher wing loading and increased aspect ratio 

with performance gains in high-speed flight. Also 

new at Binder in Ostheim is the “EB 29:” the singleseat 

sister of the “EB 28” will have a wingspan of 

29.3 meters. The fuselage of the “EB-29” will be 

about one meter shorter, and the fin less swept and 

taller than that of the “EB 28”. Finally, the new 

Schleicher 2-seater “ASH-30” is ready to replace 

the “ASH-25”. 

Maiden Flight of 

the “DG-1001 M” 

The latest self-launch version of this DG two-seater 

(www.dg-flugzeugbau.de) performed its first flight in 

Bruchsal in May. This impressive high-performance 

glider is powered by a 70-horsepower Solo motor 

“Typ 2625” with electronic fuel injection. Should the 

electronic fuel injected ever fail, a carburetor 

system is there for back-up. Getting the power from 

the motor to the prop is out of the ordinary, using 

five belts. This power transfer isolates the motor 

from the propeller arm and is designed to reduce 

damage to motor and belts. 

Redaktion Großsegler 

Page 40: 

- The prototype of the new “Arcus” 2-seater by HB-Modellbau. Owner Heiko Baumgärtner is particular about quality 

work. Photo: HB-Modellbau 

- 5. Thermikpokal Giengen: Ralph Mittelbach from Nürnberg won with his “ASW-28” in semi-scale/scale class. 

Page 41: 

- The new “Ventus-2cx” by Wemo-Composite (wing span 7.5 meters) is offered in all-molded glass/carbon 

construction. 

- A look inside the cockpit of the new “Arcus” 2-seater by HB-Modellbau: plenty of room for a scale cockpit. Photo: 

by HB-Modellbau 

- Thermikpokal Giengen: AUFWIND-author Gerald Reischl won the trophy for his win in the purpose-designed 

class and the one for overall best performance. 

Page 42: 

- Weilheim: Participants came from several different countries. 

- HKM-Grosseglertreffen: A lot was happening in Jüchen-Wey. Photo: HKM-Modellbau 

- HKM-Grosseglertreffen: 2.5-scale models dominated, like this “ASW-15B” by Ulrich Hunschok Modellbau. Photo: 

HKM-Modellbau 

September/October

A Worthy Successor 

The “Espadita” by Euromodell 

A mild summer breeze wafts up the slope. I check my 

watch — it’s 6:30PM. “Dinner at 7” was the word at the 

hotel which just a short time ago served as work meeting 

place. Oops, time to go. While I’m packing up my 

bungee at the small north-east facing slope above Bad 

Herrenalb near Karlsruhe — I had found it more by 

accident — I think to myself: slope flying simply is fascinating, 

it makes one happy and addicted at the same 

time. Barely do I drive to a meeting, and already, without 

much ado, I’m given the gift of enjoying interesting 

test flights for this report in the evening glass-off. All 

thanks to a small and easy-to-pack model called “Espadita.” 

She’s been announced long ago. She was to be the 

successor of the “Mini Ellipse,” but she has not yet 

replaced that model. Many rumors preceded the plane, 

and talking on the phone with Wolfgang Miny of Euromodell 

two years ago, he exposed me to the “Espadita” 

virus. Its gestation period was about half as 

long as the conversation back then, and it was clear 

that a glider and electric version of this highly-touted 

model had to be added to my hangar. 

The plane finally arrived last April. The first impression 

clearly showed its lineage, and this little something 

with its two meters of wing span revealed its heritage 

through its looks and wing planform. It’s almost as if an 

“Espada RX” (see AUFWIND 5/2006) had been 

washed to hot and shrunk some more in the dryer. So 

the name is appropriate as this is essentially a smaller 

version of the “Espada RX.” 

First, I closely inspected all the parts and noticed the 

low weight. The wing halves weighed 207.2 grams 

(left) and 209.6 grams (right) without gear. The electro 

fuselage with carbon canopy and servo box added 190 

grams dry. The stabilizer halves weighed 13 and 13.2 

grams respectively, while the carbon wing joiner came 

in at 55.3 grams. Finally, the glider fuselage with carbon 

canopy and servo box was 182.2 grams dry. It 

was clear right away that this plane had been optimized. 

And just as quick, questions arose about momentum-carrying 

ability of the glider version, due to its 

low flying weight. According to Euromodell, a heavier 

DS variety of the “Espadita” is already being developed. 

The low weight also raised doubts about component 

strength. But these are swept aside as easily 

here as they are with other Jaro Müller models: you 

can’t twist or bend these wings by hand even though 

they don’t have a carbon D-box. Both fuselages are 


- 23 - 



very stiff also and have an upright spar installed in 

their boom. Also nice to see is the fact that the fuselages 

are reinforced with Kevlar throughout. These 

fuselages are thus 2.4 GHz friendly. 

Looking at the 4-servo wing, one immediately notices 

the absence of servo wells. Instead, there is a 

large opening in the root rib through which the aileron 

and flap servos are to be installed. This is the 

innovation, termed FISD, which will also be integrated 

in future Jaro Müller models. Behind this 

acronym hides a wing-internal linkage system without 

external components. The ailerons are actuated 

though a torque tube running in ball bearings, and 

the aileron servos are situated next to the flap servos 

near the wing root; the servos no longer are 

positioned out on the wing at the ailerons. The 

weight of the servos is thus concentrated near the 

fuselage. The flaps are actuated by a small square 

carbon rod, which is drilled to accept the flap pins. 

Small brass tubes inserted in the holes of the 

square rods assure a precise and slope-free linkage. 

An installation free of external linkages is not really 

a new thing, as seen with RDS (Rotary Drive System; 

see AUFWIND 4/2009), which also is completely 

enclosed within the wing. The main difference 

between FISD and RDS is the former’s lack of 

complex fitting and adjusting work or special servo 

frames. With FISD, the output gear of the flap servos 

automatically inserts into a specially machined 

part, which, like a crankshaft, engages the flap linkages. 

These machined parts and the torque tubes 

for the ailerons have ball bearings where the servos 

engage. The result is a slop-free and extremely 

precise linkage. 

The assembly continues with more “plug & play,” 

and both glider and electro versions are free of 

challenges. The instructions are complete with 

many photos, and assembly of both versions is 

quick and easy, also because the empennage linkages 

(carbon) are completely installed at the factory 

and only have to be attached to the servos. No 

clevises or servo arms are needed for this, because 

the included aluminum parts fit exactly onto the 

output gears of Futaba “S-3155” or Graupner “C- 

271” servos. These aluminum parts are secured 

with grub screws, and the carbon push rods are 

simply screwed on. The servos are mounted tan- 

September/October

dem in the wooden box, which is bolted to the fuselage 

with two screws. After installation of the receiver pack 

(4x GP-2200 inline), there is enough room in the glider 

fuselage to add a “Picolario Log” by Renschler Instruments. 

The included tow hook is a u-shaped piece of steel 

music wire which gets inserted through the pre-drilled 

hole in the fuselage with epoxy, thickener, and two 

layers of fiberglass. The wing servos are connected to 

the fuselage using the included Multiplex plugs. This 

means, after the wiring harness is finished, the glider 

version is ready for balancing. 

The electro fuselage takes a little more time. The main 

question here was which power system to use. From 

my “Mini Ellipse,” I was used to rather brisk power, so 

the new plane should be just as powerful. Euromodell’s 

recommendation is power systems between 200 and 

350 Watt, such as a Hacker “B40-12S” with 4.4:1 

gearbox and a 13x9 propeller. The fuselage has room 

for a motor of maximal 28 mm in diameter. Because of 

the small space, and keeping the center of gravity in 

mind, the drive train should be as short and light as 

possible. I wanted to test different motors with different 

props and chose the Kontronik “Kira 400-39 5.2:1” and 

“Kira 400-34-5.2:1” along with a Hacker “B40-10S” with 

4.4:1 gear box. The motor mount of the “Espadita” 

already is marked for the mounting holes of the “Kira” 

systems, so that proper alignment is assured. The 

“B40” has a fiberglass motor mount included, which I 

used as a template, because it already had the 10-mm 

center hole for the shaft. Because both motors need 

this 10-mm center hole for the gearboxes to sit flat 


- 24 - 


against the mount, the holes for the mounting 

screws can be drilled accurately by lining up the 10mm 

holes in the template and the mount. The “Espadita’s” 

motor mount is installed with some side 

and down thrust, and motors of the 400 class will fit 

fine. If using motors of the 480 class, one may have 

to relieve the fuselage wall on the inside a little to 

allow the motor to be mounted without tension. 

For a controller, I chose the new Kontronik “Jazz 80 

LV,” whose BEC delivers a stable 4 Amperes and 

allows fearless flying while using all servos. The 

size of the “Jazz 80 LV” is 52x25x11 millimeters; 

this size and its 58-gram weight present no problems 

for installation. Other controllers with similar 

dimensions will also fit. But you have to get the 

controller as close to the motor as possible to allow 

sufficient room for changing the battery. 

The small size of the fuselage limits the types of 

batteries which can be installed. I tested two: a 3s 

LiPo 2100 mAh by Graupner/Kokam (186 g) and a 

hacker “Flightpower EVO25 with 2170 mAh (177.8 

g). When I wanted to install the Kokam LiPo, I found 

out it was slightly wider than published dimensions, 

and it fit only after removing the outer plastic case. 

The Hacker LiPo fits perfectly, and it’s 10 grams 

lighter, which later helped getting the CG right. 

Before the first flight, I measured the static performance 

of the three drive trains with various carbon 

fiber propellers. The spinner’s yoke ad a diameter 

of 36 mm. The battery was recharged after each 

test to obtain comparable results: 

Size Manufacturer „Kira 400-34“ „Kira 400-39“ „B40–10S“ 

[A, RPM) [A, RPM) [A, RPM) 

12x7” Graupner CFK 15, 7.000 21, 7.680 30, 8.530 

12x7,5” Robbe CFK 16, 7.120 22, 7.410 32, 8.320 

13x7“ Graupner CFK 17, 6.820 25, 7.530 35, 7.900 

13x8“ Graupner CAM 21, 6.600 30, 7.380 41, 7.850 

14x6“ Aeronaut CAM-Carbon 21, 6.510 30, 7.280 42, 7.840 

14x8“ Aeronaut CAM Carbon -, - 49, 6.900 48, 7.330 

14x9,5” Graupner CFK -, - 50, 6.300 55, 6.730 

I also flight-tested these combinations. This yielded 

two set-ups which ideally matched their purpose: For 

moderate climb angles with low power consumption, I 

preferred the Kontronik “Kira 400-34 5.2:1” with the 

14x6 prop. With it, I achieved up to 10 climb to about 

200 meters altitude. Using the 13x7 prop instead allowed 

for a slightly longer motor time at a lower climb 

rate. The second set-up was the hottest of them all: 

Kontronik “Kira 400-39 5.2:1 with Aeronaut’s inexpensive 

14x8 propeller. At 49 Amps current draw, this setup 

gave me four to five rapid climbs to speck hight. 

The Graupner 14x9.5 prop does have a higher pitch 

but narrower blades, and thus has only a slightly 

higher current draw. Also quite powerful and in between 

these two was the Hacker “B40-10S” swinging 

the 12x7 prop. With this drive train, the plane 

climbs nearly vertical, yet power consumption is 

moderate. This system allowed up to six long 

climbs. 

The ready-to-fly weight of the “Espadita” electro 

version (“Kira 400-34 5.2:1”) was 1,314 grams. 

September/October

Upon launch, the model climbed straight and powerfully. 

After a short climb yielded sufficient test altitude. 

The ”Espadita” flew in a long flat glide until a small 

“bump” indicated the first thermal. Add some camber, 

and here comes a harbinger of this model’s thermal 

performance: I added only 2 mm of camber just to the 

flaps, yet this slowed the model sufficiently to use the 

relatively weak thermal. Also, because the plane is so 

small, it nearly turns on a dime. If you add even just a 

little camber to the ailerons also, the model slows even 

more, too much so for weak thermals. But in strong lift, 

full-span camber yields clearly higher climb rates. 

Within a few minutes, the model had climbed sufficiently 

high for the obligatory dive test, or so I thought. 

I put the plane in a vertical dive, and oops, the model 

accelerated so rapidly that I had to end the test before 

it really had started, because there just wasn’t sufficient 

altitude left to check for self-recovery. Obviously, 

this model has a wide speed range: it inconspicuously 

glides around the sky, but unleash it, and you’d better 

have a good sense of the available air space. Due to 

the extra weight of the electro version, the plane 

quickly gets noticeably faster than the “Mini Ellipse.” 

300 meters of dive test altitude were burned rapidly. 

Ok, up again, this time to speck altitude. A quick check 

of the air space and another vertical dive. Well, the 

plane stayed on course with no indication of selfrecovery. 

Obviously, the recommended CG of 74 mm 

was right on and in my opinion ideal. I did a a quick 

check with a more forward CG, but because the model 

flies perfectly with the CG at 74 mm, I set up both versions 

that way. 

I found the recommended control throws to be correct. 

Mixing a tad of flap camber to up-elevator results in 

pleasant thermaling on one hand, and tight turns and 

loops on the other. For a higher roll rate, I mix some 

flap deflection to the ailerons. The electro version flies 

without bad habits so long as air speed is kept up. The 

empennage, particularly the full-flying stabilizer, are 

ideally sized, in my opinion. Like in the “Espada RX,” 

two ball bearing are used in the horizontal stab. 

The electro version really fascinates me with its thermal 

performance coupled with good energy retention. 

So now I was eager to finish the glider version. Because 

the RC installation is the same, this 200-grams 

lighter model soon was ready for testing. 

The maiden flight was off a bungee over flat terrain. 

Because I intentionally placed the receiver pack as far 

forward as possible, installation of a bungee hook was 

not possible; so the tow hook had to do. I added 10 

meters of string to the bungee, stretched the latter near 

its limit, and left the “Espadita” to its own devices. With 

a loud whistle, the model rocketed forward then 

climbed upward rapidly. After a quick zoom, the plane 

ended up at 76 meters, according to the variometer. I 


- 25 - 


was fascinated. How can these 1110 grams be 

accelerated so quickly and shoot skyward so high? 

The answer probably lies in the thin airfoil. It’s responsible 

for the interesting speed range of this 

plane. I immediately went to look for a thermal and 

noticed the excellent glide. The Variometer did not 

make sinking noises, so altitude loss must have 

been minimal. A quick cruise around the field revealed 

a good thermal which required tight circling 

at first; only above 100 meters did the thermal 

spread out a bit. Despite the low weight, the “Espadita” 

tracked well and felt solid, even with cambered 

flaps. It was clear that this light-weight glider 

version responds to the smallest bits of lift, a fact 

which was confirmed during slope testing. One 

evening, for example, lift was so light, only handlaunch 

gliders were able to stay up; but the “Espadita” 

could hang with them. While the electric 

version is convincing with it thermal performance, 

the pure glider really shows what’s possible. 

Where there is light, there is shadow: energy retention 

is lacking. While the model accelerates willingly 

to a high rate of speed, the energy fizzles out 

quickly. This is supposed to be helped with a steel 

joiner, which adds about 300 grams of weight. Also, 

the carbon joiner has full-length voids which will 

hold up to 200 grams of ballast. In my opinion, 

these are no real solutions. Better would be ballast 

tubes in the wings, which could hold at least 500 

grams. 

Also of note is the fact that the light-weight construction 

takes its toll on the strength of the flap 

hinge. The hinge material has to be built stronger, 

because my model showed hinge breaks up to 5 

cm long after just ten flights, during which the flaps 

were exposed only to normal flying forces. Euromodell 

already says it’s addressing the problem. I 

fixed the hinges on my model with “Elastosil E41” 

without problems. 

I flew both model versions throughout the 2009 

flying season, and I had a lot of fun doing it. There 

were no unpleasant surprises during any of the test 

flights in Fiss, Davos, Monte Lema, Schwarzwald, 

or at home at the Teck. The test flights amounted to 

about 30 hours, with more hours on the glider than 

the electric version. The “Espadita” is an innovative 

exception to the rule and convinces with a wide 

speed range and excellent thermal ability. Its agility 

makes it a lot of fun to fly. It’s light and strong and 

has no problem with most aerodynamic forces. 

Easy assembly and disassembly and a small 

packed size round out this model. In my opinion, 

the “Espadita” is a worthy successor of the “Mini 

Ellipse.” 

Andreas Wiegner 

Photos: Julia Wiegner, Theo Arnold 

September/October

Data: 

“Espadita” by Euromodell 

A small high-performance model 

Wing span: 1.993 mm 


Weight Glider: 1.110 g 

Weight Electro: 1.314 g 

Surface area: 28,5 qdm 

Surface loading G: 38,95 g/qdm 

Surface loading E: 46,11 g/qdm 

Airfoil: HN-065 JM 8,5/1,85 

Price: 669,- Euro; Euromodell, Germany, Tel. +49/6881/2129, www.euromodell.de. 

Photo captions: 

Page 44: 

- A powerful drive train turns the glider into a fun electric plane. 

- The “Espadita” is a compact high-performance model in both glider and electro versions. 

Page 45: 

- The accessories; clearly visible are the parts for the FISD linkage. 

- The tail seems fragil, but it optimizes strength and function. 

- Only an in-line battery will fit in the glider nose. 

Page 46: 

- The electric nose is bit tight. 

- Flight performance is outstanding, except for carrying momentum in the unballasted glider version. 

Page 47: 

- The electric version includes “sink-out insurance” and built-in ballast. 


- 26 - 


September/October

High‐Tech from Swabia 

The 2.4 GHz System by Weatronic 

Pilots of scale models know Weatronic best. The company’s 

35-MHz radio gear frequently is found in their 

expensive models. I admit, flying medium to smaller 

models, I have mostly overlooked Weatronic ads. 

Why? Well the products carry a high price tag and 

appear to be for high-end users only. Aren’t they overkill 

for “normal” models? 

My estimation was not quite right, because even the 

big receivers, which deservedly are referred to onboard 

electronics, have a good performance-to-price 

ratio. Where else could you get a completely redundant 

Diversity receiver with built-in intelligent power 

supply, up to three built-in gyros, and GPS, all in one 

box at a price of 800 Euros? If you added up the prices 

of these components separately, you’d come up with a 

whole lot more money than that. Of course, this assumes 

you need all these features. But I admit that just 

the look and the sense of quality of this receiver line is 

impressive. 

And I was thoroughly surprised to see more economical 

combinations of TX/RX modules in the 2.4 GHz 

series. This is made possible by the new microreceiver 

line without GPS or gyros. These receivers 

come in 8, 10, and 12-channel versions. For this report, 

I’m testing the 12-channel mini-receiver; I’ll do the 

big one later. 

2.4 GHz has become a much debated and discussed 

subject recently. Topics range from functions, ways to 

transmit, and legal issues. In this article, I’ll highlight 

the differences of the Weatronic system to that of other 

manufacturers. Here is an overview of Weatronicspecific 

features, which make the purchase of a 

Weatronic combo interesting: 

Weatronic chose its own independent concept during 

development of its 2.4 GHz systems. They tried to get 

the most out of the new wide-band technology. This 

meant developing from scratch rather than incorporating 

existing 2.4 GHz components. To fully exploit the 

maximal allowed transmission power of 100mW and to 

minimize interference issues, the so-called FHSS 

process was selected. FHSS means Frequency Hopping 

Spread Spectrum. Weatronic uses up to 80 channels, 

which, depending on country, use the maximalallowable 

band width. In France, for example, only half 

the bands are available. The one-megahertz wide 

channels are scanned in about 1/100th of a second so 

that double assignment of a channel has virtually no 

effect on operation. Such channels are blocked for 


- 27 - 



while, only to be used again later when the interference 

has stopped. This process is called “adaptive 

frequency hopping.” With Weatronic, channels remain 

blocked only if they are used by high-powered 

transmissions. Other manufacturers use only three 

or 16 bands, so that the availability of clear channels 

is greatly reduced if interference from highpowered 

transmitters is present. Weatronic also 

implements a complex error correction, which also 

can be found in 35 MHz receivers today. This one, 

however, is preventive correction, one which predicts 

the type of error correction needed. 

Let’s look at the components: The transmitter module 

is inside a small box which is attached like the 

regular antenna; it has two sealed and stiff push 

buttons. The module comes complete with adapters, 

adapter boxes or adaptor circuit boards, and 

necessary cables. It took only a few minutes to 

install onto my Multiplex Profi MC-4000 transmitter. 

I noticed that the module could twist on its adapter, 

which might damage the cable accidentally. I recommend 

securing it with some removable glue. The 

module has an audio-out plug for alert sounds, 

which in the future may also be used for a variometer. 

Transmission is bi-directional, so there are 

many possibilities for future uses, even telemetry. 

The module also has a serial interface where additional 

modules could be plugged into as they become 

available. 

Now let’s have a look inside: The transmitter module 

really is two redundant modules which send and 

receive using two surface antennas. These use socalled 

circular polarization and transmit in a way 

which is clearly superior to traditional W-LAN stub 

antennas. If one measures transmission power in 

real time and spins around with the transmitter, one 

notices only small fluctuations, transmission truly is 

omnidirectional. The module records transmission 

and reception data onto a SD-card. The built-in 

capacitors allow the module to continue transmitting 

for a while if the transmitter battery were to fail, so 

the cause of this failure also is recorded. Someone 

was thinking! An acoustic signal warns the pilot if 

the voltage to the receiver drops below the threshold. 

Another warning sounds when the range limit is 

reached. Range is up to 3 km on the ground, farther 

in the air. The warning thresholds can be configured 

using the “Giga-Control” software. 

September/October

The transmitter module’s LEDs show exactly what’s 

happening. A green LED reports all systems normal, 

red means interference, and yellow is for range testing 

at 1/100th transmission power. The bi-directional 

transmission shows transmitter and receiver interference 

at the module in real-time. This includes disruption 

caused by low-voltage or too thin receiver battery 

cables, for example. Interference also happens if the 

transmitter is within 30 cm of the receiver. This type of 

interference appears to be a common occurrence with 

2.4 GHz systems. My “Nimbus 4” has 10 servos in the 

wing, and it showed problems when testing butterfly 

settings. This is due to rapid switching between failsafe 

and normal operation. Therefore, fail-safe should 

be programmed beforehand such that the motor won’t 

start accidentally. In my case, the receiver mercilessly 

reported insufficient receiver power. Weatronic receivers, 

when idle, require four times the current of 35- 

MHz receivers. Of course, they also transmit. What 

does this mean for their application? Even though they 

weigh only 19 grams, I wouldn’t use them for very 

small or light models, because for such models the 

necessarily big receiver battery adds unwanted weight. 

Still, the extra safety may be worth it in some smaller 

models. The Weatronic module reports interference 

optically and acoustically before the model is launched. 

Using the “Giga-Control” software, causes of the interference 

can be isolated systematically and in real-time. 

Also for smaller models, keep in mind that while 8, 10, 

and 12-channel versions of the micro receiver are offered, 

they only differ in price, not in dimensions or 

weight. The reason for this is that there are two circuit 

boards. There also are two HF-modules, each with its 

own antenna. This guarantees full antenna diversity. 

Signals from both antennas are evaluated constantly 

for completeness and validity. Fail-safe can be programmed 

with the transmitter separately for each 

channel. Thus, the “Dual-Receiver 2.4 Dual FHSS 

Micro” series, like the big on-board electronics, is designed 

for maximum safety and current loads. This 

includes extensive filtering of all channels, 5 Volts for 

signal, operating voltage of 4 to 9 V, an external electronic 

switch, and a high temperature tolerance. This 

safety of operation has been proven in tests of up to 

30A in the big receiver, and up to 5A in the small one. 

For very small models, Weatronics currently is developing 

products which can handle less current but also 

are smaller. I’m looking forward to seeing what they 

come up with. Fact is that almost all 2.4 GHz system 

have the disadvantages of higher current draw and 

bigger size. But so long as they maximize safety and 


- 28 - 


performance, like the Weatronics products, they are 

on the right path. 

“Giga Control” is a complete software solution for 

transmitter/receiver combinations, which allows 

monitoring and configuring of all Weatronics 2.4 

GHz products. This comprehensive software will be 

the subject of a future article, but here is a list of the 

main features: 

- Transmitter module: transmission quality in percent, 

filtering in dB, transmitter battery voltage, voltage 

at the USB interface, temperature inside the 

transmitter, modulation, battery warning, range 

warning, temperature warning, language selection, 

and audio volume. 

- Receiver: battery voltage, battery warning, reception 

quality, and temperature. 

- Servo Monitor: you can check individual servos or 

groups of servos, such as where more than one 

servo is used per control surface. Because for each 

servo travel curves and mixes can be programmed, 

slight differences among servos hooked up to the 

same control surface can be eliminated. Even servo 

sequencers for self-launch system or retractable 

landing gears can be programmed, as can gyro 

attributes. Three different fail-safe settings are 

available for each channel. 

A highlight to me is the spectrum analysis which 

shows interference, channel use, and intensity per 

band. Through Nav-View, it’s possible to generate a 

log of all relevant data. Nav-View also can show the 

actual flight path, however only with receivers with 

built-in GPS. Given the gyros in the big receiver, 

we’re only a small step removed from an actual 

auto-pilot. 

All this begs the question as to why Weatronics 

doesn’t offer it’s own whole transmitter with which 

compatibility might be better yet. It’s a legitimate 

question deserving of a thoughtful answer. Fact is, I 

have not encountered a single compatibility issue 

during all my testing, even though my “MC-4000” is 

an older model transmitter by now. To the contrary, 

the reliability of signal transmission and current 

handling ability is — in my opinion — unmatched for 

a receiver. This alone justifies equipping radios of 

other brands with the Weatronics system. For tech 

freaks, “Giga-Control” offers the analysis also of 

receiver data… in real-time! A few moths ago, such 

controllability and safety could only be dreamt of. 

Volker Kaul 

September/October

Data: 

Transmitter Module: 120 x 75 x 30 mm, 225 g 

12-channel Receiver: 55 x 35 x 19 mm, 19 g 

www.weatronic.com 


Page 52: 

- The transmitter module mounted to the Multiplex MC-4000. 

- The 12-channel receiver suffices for most applications and weighs only 19 grams. 

Page 53: 

- The flag-ship of Weatronic receivers is the “12-30R Gyro + GPS” which satisfies all demands. 

- Receiver settings of the “Giga Control 2.4” software. 

- Using the “Servomonitor,” ganging up several servos to one control surface is easy. 

Page 54: 

- Nav-View records all relevant data. If using receivers with GPS, the flight path can be recorded also. 


- 29 - 


September/October

The 16‐Year Project 

A Scratch-Built “Grunau Baby IIb” 

„ARC“, „ARF“, „RTF“ and other cryptic acronyms are 

common place these days in the model airplane world. 

In recent years, planes built in the Far East have conquered 

the market and vastly reduced the time spent 

at home in the shop. That can be attractive. After all, 

who can resist the temptation to get a chosen model 

airborne in minimal time? Especially if the price is 

rather moderate? 

Scratch-building from plans is a much bigger challenge. 

Here, the modeler has the time during the many 

shop hours to develop a rather intimate connection to 

the model. The nostalgic value far exceeds the financial 

expense. The completed plane is always unique, 

and the builder is assured to have created an exclusive 

model, which won’t be found in large numbers at any 

flying field. Counting the hours as an expense is not 

allowed, of course. The motto is: “It’s all about getting 

there,” and the building process is an enriching and 

educational life experience for every modeler. And so it 

is with the “Grunau Baby IIb” described here. 

With over 5000 units manufactured, the “Grunau Baby 

IIb” today is regarded as the most-built glider of all 

times. The designer Edmund Schneider developed the 

first version in 1931/32, and many others followed. The 

most-built and best known one was the “IIb.” Starting in 

the ‘30s, the glider was considered an ideal trainer with 

docile handling. In 1933, the “Baby” flew a new duration 

world record with 36 hours aloft, which was excellent 

testimony to its performance. The plane had an 

L/D of 17 with a maximum speed of 150 km/h, specifications 

which were remarkable back then. Today, 

many “Grunau Baby” still fly in many countries. The 

design is optimized for easiest possible construction 

and low weight, and the plane has few compound 

curves. The docile flying characteristics of the original 

and its simple construction are easy to transfer to a 

model and experience the spirit of wood construction 

of the ‘30s. 

Because the “Grunau Baby” also is a symbol of vintage 

gliders for modelers, quite a few are offered on the 

market. Possibly best known are the Krick models by 

Karl-Heinz Denzin, which have been offered in quarter- 

and sixth-scale versions for many years. Arthur 

Mackenroth designed and published the plans for a 

4.5-scale “Grunau Baby IIb” with 3-meter span, and 

this report is about this plane. 


- 30 - 



So is this a story about a 16-year building project? 

Not quite, as it really is two winters spent in the 

shop with 15 years in between. Even in an oftenideal 

father-son RC symbiosis, there are differing 

preferences regarding modeling subjects. The senior, 

a skilled wood builder since childhood, has always 

loved classic wood construction. He quickly 

ogled the construction of a scale “Grunau Baby.” 

Junior preferred to satisfy his juvenile adrenalin 

needs with “hot” models, such as “Me-163,” “Me- 

262,” and “F-104 Starfighter.” He even dabbled in 

paragliding, but couldn’t quite relate to his Dad’s 

“wood-craze.” Sickness, unfortunately, prevented 

me from finishing the model back then. The halfdone 

“Grunau Baby” disappeared in the back corner 

of the attic, where it collected dirt and dust and 

suffered hangar rash. 

Fast-forward 15 years, several moves, and the 

starting of a family for Junior: now also mutated into 

a woodie lover, Junior remembered the classic 

wood plane. Meanwhile, the “Grunau Baby” was in 

a pitiful state. It was covered in dust and was damaged 

in several places. Particularly annoying was 

the tape residue on the wings; the glue had penetrated 

the balsa wood. This problem was addressed 

later with some solvent. Nonetheless, restoration 

and completion of the model were started with a 

passion. Because Junior had been given plenty 

know-who by Dad, even this plan with difficulty level 

4 (“builder with solid experience”), was no problem. 

The two-piece wing has a fair amount of wash-out 

at the tips and the complex-to-built ailerons. The 

exactly-drawn and easy-to-understand plan clearly 

addresses this build in great detail. Like the original, 

the model has struts, but Arthur Mackenroth used 

two 6-mm steel joiners, which would be strong 

enough on their own to fly the plane without struts. 

The struts are made from 4-mm threaded rods 

faired with wood, and they add substantial strength 

such that even winch launches cause no concern. 

The spoilers used to be actuated by a central servo 

in the fuselage. But today, there are many suitable 

servos, so I saved myself some trouble and installed 

two spoiler servos in the wing. We finished 

the fuselage with clear coat and covered the wings 

and tail with “Oratex Antik” fabric-foil. A distinct 

advantage of the years-long storage was the darkening 

of the balsa wood. While many vintage glid- 

September/October

ers have to be aged artificially, this natural aging in the 

attic produces a truly scale appearance. 

The plan calls for flying weight of 2.5 kg, which I didn’t 

meet. My “Grunau Baby” required a healthy chunk of 

lead in the nose, and it weighs 3.1 kg. It’s easier for me 

to blame all the dust for that than to admit that the tail 

group turned out kind of heavy. 

The maiden flight was no problem behind an experienced 

tow pilot. From the beginning the “Grunau Baby” 

flew stable and easy. The stall is mild as expected. L/D 

of course is rather scale-like and cannot be compared 

to that of modern performance gliders. But extended 

thermal flights are nice at minimum-sink speed. The 

“Grunau Baby” requires an aileron rudder mix for 

proper turning. Spoiler response is excellent and 

makes landing easy, even though landing without 

spoilers is quite manageable due to the relatively low 

L/D. 

Data 

“Grunau Baby IIb” 

A design by Arthur Mackenroth 



Flying Weight: 3.100 g 

Wing Airfoil: NACA 4412 mod. 

Decalage: 2,6 Grad 



- 31 - 


This vintage glider looks great in the air, particularly 

when the light shines through the covering to reveal 

the wood structure beneath. Anyone who looks up 

from the ground and sees the sun shine through the 

wing is captivated by the beauty and elegance of 

the sight and admires the timelessness of the 

“Grunau Baby.” 

After 16 years of building history and many enjoyable 

flights, I’m left with the satisfaction of having 

once again experienced wood building at its best 

and basic level. A scratch-built vintage woodie can 

bring deep satisfaction to a model builder. The 

wood gliders of the ‘30s offer many interesting subjects 

to be inspired by. “Back to the roots” can be 

very educational, captivating, and enjoyable in today’s 

often fast-paced RC gliding scene. 

Stefan Maß 

Page 56: 

- Vintage gliders exude an elegance incomparable to modern performance gliders. 

- Essentially in second generation, the resurrected “Grunau Baby” finally flies after 15 years of attic storage. 

- Aero-tow is the easiest way to get such scale models airborne. 

Page 57: 

- Thanks to responsive spoilers, the plane can land in small spaces. 

Page 58: 

- It’s exactly this sight of translucent wings which fascinates young and old alike. 

Page 59: 

- The 4.5-scale model built from plans next to a 6th-scale Krick “Grunau Baby.” 

September/October


- 32 - 



Tradition meets Modern Ways 

“Premiant II” by Aeronaut 

The “Premiant II” is a classic electro-glider, built with 

modern components, and designed to be a docile 

model. Its modified Eppler E-393 airfoil likes to fly 

slowly, and that combined with easy controllability, 

makes this plane an excellent trainer for beginners. 

The model is available with optional spoilers. 

The kit contains a flawless fiberglass fuselage, a blue 

canopy, foil-covered wings and tails, and all necessary 

accessories and decals. All control surfaces are factory-hinged 

with foil. The 6-page instructions with photos 

illustrates what little assembly there is. Workmanship 

and quality, especially those of the covering, are 

top notch. Only the wooden dowels used for joining the 

wing panels would be better if cnc-machined. 

The polyhedral wings are built-up. Fiberglass tubes 

serve as main spars, and the wing halves each have 

inner and outer panels. Dihedral is set, and the panels 

are joined with the wooden dowels. I chose not to install 

the spoilers, because raising the ailerons as 

spoilerons usually suffices for glide-path control. But I 

do have to say that the spoilers are excellently prepared 

at the factory. They are pushed open by the 

servo arm, and a steel spring pulls them closed — 

simple and effective. A three-pin MPX connector gets 

soldered to the wiring of the “D-90” aileron servos and 

epoxied into the root ribs. If you don’t want to do this, 

simply add an extension cable and let the plug hang 

out at the root rib. I covered the servos with heat-shrink 

tubing and glued them in with Beli-Zell. I didn’t use the 

included plywood servo covers and simply closed the 

servo wells with iron-on covering. The wing joiner system 

consists of a brass tube which has to be epoxied 

into the root ribs. This is old school and needs to be 

done precisely, else it won’t fit. So take the time necessary 

to assure proper alignment. Two carbon locator 

pins complete the joiner system. 

I modified the servo tray to fit the “D-90” servos as far 

aft as possible. While I completed the model, I found 

out that the servo tray should be mounted as low as it’ll 

go. I squandered space here, and because this resulted 

in nose-heaviness, had to reposition the battery 

tray and enlarge the opening in the fuselage. Well pre- 

pared was the elevator linkage with glued-on wood 

block and threaded-on formers. This resulted in a 

smooth linkage without kinks. The canopy fit perfectly 

and is held on by two fiberglass tongues. The 

motor mount is made from fiberglass and is predrilled 

for the recommended “Actro C-8” motor. I 

epoxied it in and adjusted it for down and side 

thrust as per instructions; I also used the 36-mm 

Aeronaut “Cool Nose” spinner as a guide. The propeller 

is a 13x8 “Cam-Folding,” and I installed a 

Kontronik “Pix 4000” controller. The “Actro C-8” 

spins this prop at 6,400 RPM at a current draw of 

28 A from a Hyperion LiPo 3s 1,800 mAh. This system 

delivers about 280 Watt. 

The CG can be set at the recommended 68 mm by 

moving the flight pack, which is secured with a hook 

and loop fastener. I also used the recommended 

control throws. The flying weight of 985 grams and 

the resulting low wing loading promise very docile 

flying characteristics. 

Before the first flight, I performed a quick check and 

secured the wings with tape. The “Premiant II” 

climbed at about a 30-degree angle. Power is more 

than adequate, and two thirds throttle suffices for 

zippy flying. Rudder and elevator response is direct 

and quick, which confirms the good layout of this 

glider. But aileron response was slow, and I increased 

the throws and mixed in some rudder. If 

you stall the “Premiant II,” it rolls slightly to one side 

and picks up speed, but control is regained immediately. 

The model also is plenty strong and allows 

simple aerobatics such as loops and inverted flight. 

The low wing loading results in good response to 

thermals. Thirty-minute flights often were possible 

with only 6 minutes of motor run time. Applying 

spoilerons mixed with 6 percent down-elevator allowed 

safe descents from high altitude and precise 

landings. 

A flawless product from Reutlingen — Made by 

Aeronaut. 

Thomas Navrath 

September/October

Data 

“Premiant II” by Aeronaut 

A classic electro glider for everyone 


Length: 985 mm 

Flying Weight: 985 g 

Motor: „Actro C-8”, Aeronaut 

Controller: „Pix 4000“, Kontronik 

Propeller: 13x8“, Aeronaut 

Flight Pack: 3s 1.800 mAh, Hyperion 

Control throws: 

Elevator: -8/+6 mm 

Rudder: +/-25 mm 

Aileron: -15/+8 mm 

Landing: 


Elevator: +1,5 mm 

Center of Gravity: 68 mm 

Price: 219,- Euro; available at dealers, www.aeronaut.de. 


Page 60: 

- A perfectly-fitting drive train with 3s LiPo battery. 

- Two-meter electro gliders with affordable propulsion have been popular for decades. 

- The root ribs do not fit perfectly, but they’re close enough. 

- The strong suit of the “Premiant II” is soaring, and it finds even the weakest thermals. 

Page 61: 

- Nice parts from Reutlingen; the kit is very complete. 

- A very classic-looking T-tail. 

- Space is limited; the flight pack sits on the rails. 

- AUFWIND Author Thomas Navrath likes this compact electro glider. 


- 33 - 


September/October

A Double‐Meter 

“FireworXtend” by PCM 

Two meters of span but only 430 grams flying weight, 

a fast flapped airfoil for sniffing out thermals and to go 

fast. Add to that about a 45-meter discus-launch height 

in the flats. A few years ago, discus launching brought 

about a new generation of gliders. Until then, helpless 

waiting for hooking a thermal could only be ended with 

the help of a winch, bungee, or motor, all things we 

sure could do without. “Handlaunch into Thermals” 

were the headlines describing the first hand-launch 

gliders — rather boring planes in my opinion: slow, 2axis 

wood models. I’d rather drive to the hills to have 

fun on the slopes. Then came the first 3-axis handlaunch 

gliders — now called DLGs — “real planes” 

with ailerons, camber changing, and high performance. 

But these are a bit small for far-ranging flights. This 

niche is filled by the “FireworXtend.” The hills see less 

of me now, I’m saving gas without giving up fun. 

This model by PCM is a real misfit. It is purposedesigned, 

and that always raises questions. This 

model underwent an analysis of of its application just 

like competition models are optimized for their particular 

tasks. The advantage here is that no artificial road 

blocks in the form of rules had to be considered, but 

only physical laws and limits applied. PCM owner Markus 

Podivin wanted to design a glider for the competition 

class “just want to fly and have fun!” He wanted 

high performance, go fast, yet catch every thermal out 

there. The model also had to break down small and be 

easily hand-launchable. 

This is how the “FireworXtend” came about. A DLG 

with a 2-meter span and about 450 grams flying 

weight. The wing had to have two halves for transport. 

A simple enlargement (English: extending) of the existing 

“Fireworks 4.2” (see AUFWIND 2/2009) wouldn’t 

do, however. Centrifugal forces rise exponentially with 

size, so a whole new tail boom had to be designed. 

Aerodynamic loads and bending forces during launch 

demanded a boom which looks a bit like a sword and, 

of course, is made from high-modulus carbon. Only the 

fuselage nose is reminiscent of the “Fireworks 4.2.” it 

has an unusually-shaped canopy: all radio gear is easily 

accessible. And there is even enough space left for 

an altimeter and ballast. 

The tail group needed to be as light as possible, but 

still be strong enough for its size. And if possible, it 

should be completely finished — fiddling around with 

springs and pull strings is not everyone’s cup of tea. 

The result is an out-of-the-mold finished hollow carbon 


- 34 - 



tail with built-in spring. PCM expertly made use of 

the 8g/qm carbon matte with balsa as sandwich 

material. The horizontal stab can be removed for 

transport. 

The 2-piece wing is completely new. A carbon 

joiner is used, and 4 screws hold the wing to the 

fuselage. The wing skin is a fiberglass balsa sandwich. 

To increase torsional strength, a framework of 

carbon rovings is laid in like grating — a so-called 

Disser version. I like this construction, because 

while Rohacell is less susceptible to moisture, it 

dents really easily. A balsa sandwich also is easier 

to repair. The spars either are full-carbon or carbon 

reinforced (carbon rovings as main spars with fiberglass 

covered balsa bracing). Prototype testing 

revealed that only wing servos made sense. This is 

so, because the servo gears do not last linking the 

1-meter long flaps from inside the fuselage. Aerodynamic 

fences clean up the airflow at the aileron 

root. 

The “FireworXtend” is delivered as follows: 

- Ailerons cut out and skin-hinged. 

- Wipers taped on. 

- Wing saddle and joiner box finished. 

- Fuselage pod and boom joined with openings cut 

out. 

- Accessories (servo frames and tray, push rods, 

bell cranks, etc.) included. 

- Tail group complete except control horn installation 

and linkage by Kevlar string. 

For the maiden flight I brought my competition HLG, 

which needed some dialing in, and of course the 

new “big babe.” With my HLG, I typically got 38-43 

meters of launch height. So I stuck the altimeter into 

the “FireworXtend”. The first throws were a bit tentative, 

as I didn’t want to pound that big wing into 

the ground right away. To my big surprise, the 

“Xtend” was easy to throw. The wing levels out 

immediately during the initial launch phase, accelerates 

quickly despite the higher weight, and pulls 

out strong. This may be due in part to the higher 

aspect ratio. I throw the big “Fireworks” 40 to 45 

meters high. 

The new model is a bit more stable in the air than 

its little brother. Speed range is excellent: the Drela 

airfoils deliver great speed when reflexed. 430 

grams is not a lot of weight, but the plane moves 

September/October

ight along. In floater mode, the model moseys along 

comfortably with an amazingly good glide. Thermal 

mode really slows the glider way down and helps turning 

in lift. Once in a thermal the “FireworXtend” is stable 

and gains altitude rapidly. The settings listed in the 

instructions are right on; try them. The plane flies as if 

on rails and instantly responds to control commands. 

All control surfaces work precisely. Landing is fun, 

because the flap deflections are easy to adjust in-flight 

and easy to control. 

Not too long ago, it was hardly conceivable to handlaunch 

a 2-meter model and stay aloft for an extended 

(pardon the pun) period. Even in dead air, the plane 

stays up for about 2 minutes. But dare give it a hint of 

a thermal… (then the darn battery forces a landing 

after about 2 hours). 

I want to mention the possibility of installing a tow 

hook. Even though the model is meant to be a DLG, it 

Data 

“FireworXtend” by PCM 

A big DLG for Thermal Soaring 



Weight: 420 g 

Airfoil: AG455ct-02f/AG47ct-02f 

Wing Area: 30,5 qdm 

Wing Loading: 13,77 g/qdm 


- 35 - 


can be nice to have other launch options. There 

may be an injury, for example, which prevents one 

from discus launching. So the hook allows an alternative 

launch method. And then there are funcontests 

like the “Gummibandlfliegen” where two 6mm 

bungees launch two planes simultaneously, 

and time and landing tasks are scored on a simple 

KO-system. This is a fun event, for which the “FireworXtend” 

is the perfect model. 

Marcus Podivin also has developed an electro fuselage. 

In other parts of the world there are so-called 

F5J competitions, which are thermal soaring contests 

using electric-powered gliders. This would be 

worthy of consideration also in our neck of the 

woods. 

Mario Testory 

Price: 486,- Euro; Podivin Composite Modellbau, Austria, www.pcm.at. 


Control Surface Throws: 

Elevator: +/-10 mm 

Rudder: +/-20 mm 

Aileron: +15/-29 mm 

Thermal Mode: 


Elevator: -0,5 mm 

Speed: 


Landing: 


Elevator: +6 mm 

Center of Gravity: 62-65 mm 

Page 62: 

- With its 2-meter span, the “FireworXtend” perfectly combines manageable size with high thermal performance. 

- The long tail boom looks a bit like a sword and is made from high-modulus carbon. 

Page 63: 

- The throw peg on the left wing makes it clear that this 2-meter model can be launched like a DLG. 

Page 64: 

- The short nose cone allows quick access to the radio components. 

- The tail group is balsa sandwiched between 8g/qm carbon mat. The horizontal stab can be removed for transport. 

- A fine detail: aerodynamic fences at the wing root. 

September/October

Philosophers’ School 

A Visit at the RC-Flight-Academy 

Don’t for a minute think AUFWIND had abandoned its 

soaring and e-flight focus. We’re just curious to see 

what’s behind the word “Academy” in this firm’s name. 

Erwin Schreiber, owner of RC-Flight-Academy 

(www.rc-flight-academy.de), explained to us the origin 

of his business in Rudelstetten east of Nördlingen: 

Living in Munich as a twelve-year-old, he started model 

flying after a ski accident. His mentor was an uncle 

who was president of an RC club near Kirchheim/Teck, 

and who had frequent contact with Graupner. This 

way, many Graupner kits ended up being sent to Munich. 

Erich practiced control-line flying before he could 

afford his first radio. At this time he was a member of 

the club FMC München-Solln, which was founded in 

1957. His career eventually brought him to the 

Nördlinger Ries. He quickly met other model pilots, 

among them also Franz Weißgerber. 

Because he was good with his hands, Erwin Schreiber 

started building models for his friends. His model flying 

knowledge also was in demand, and so, besides a 

building service, he started an RC flying school: the 

RC-Flight-Academy. These two branches still exist 

today, and helicopters now dominate the school. 

Schooling for fixed-wing aircraft is not as much in demand 

anymore, due of “Easy Star &Co.” Erich 

Schreiner finds it amazing that there is no demand for 

courses with gliders with self-launch systems, given 

that many pilots have significant difficulty with these. 

Design and construction of gliders always ran side-byside, 

and molded composite construction soon commenced. 

The first products were cockpits for Friedel 

Deffner’s “Duo-Discus.” After Friedel’s career took him 

to the US, the “Duo” was produced under contract with 

Grupp-Modellbau. Late in 2006, production and sales 

were consolidated at RC-Flight-Academy. The “Duo” 

(1:3.3 scale) made the company well known among 

insiders. Word-of-mouth went around fast, due to constant 

improvements in quality and ingenuity, coupled 

with excellent flying characteristics. By now, the “Duo” 

is present at many events, and its popularity is rising, 

especially when equipped with Florian Schambeck’s 

“AFT” self-launch system. 

The philosophy of the firm puts quality “Made in Germany” 

above all else. Erwin Schreiber particularly emphasizes 

punctual delivery at the agreed-upon time, 


- 36 - 



even though the waiting list is several months long. 

Another important point is the ready availability of 

spare parts. 

A year ago came the introduction of the “OMF 100- 

160 Symphony” as an in-house, semi-scale sport 

and tow plane. The fully-molded 3.2-scale tug was 

meant for Erwin Schreiner’s personal use. He simply 

didn’t like the run-of-the-mill tugs anymore. Surprisingly, 

tow pilots were very interested, and a 

small series of models has been built in its first year 

of production. The “Symphony” is designed for 100cc 

boxer engines and for 140/150 size “King” engines. 

An Electric version is under development — 

because there is demand already — and it won’t be 

long before it’s introduced. 

Customers of “RC-Flight-Academy” can choose 

how much prefabrication they would like. Currently, 

about 80% of the planes are delivered ready-to-fly, 

with all servos, dual power systems, propulsion, etc. 

installed at the factory. Available accessories include 

wing bags by Tanja and Jürgen Stutz (www.tjflaechentaschen.de). 

As we were talking and walking through the facility, 

Erwin Schreiber mentioned that design and production 

of high-quality models is possible only with an 

active and competent team. Top pilots like Theo 

Arnold and Christian Etter are flying Erwin’s products 

and inspire continuous innovation. 

Erwin Schreiber’s newest product is a 3.25-scale 

“Pilatus B-4” with a 4.6-meter span. He choses this 

size purposely, also for future products, because it 

is still manageable, easily transported, and affordable 

for a lot of customers. The “B-4” is designed to 

be a full-on, full-throttle aerobatic glider. The next 

project will be a Schempp-Hirth “Arcus,” again 

3.3rd-scale with a 6.06-meter span. The wing molds 

are currently being made. A 3.3rd-scale ASK-21 

(wing span 5.15 meters) will expand the product 

line of the “RC-Flight-Academy” next year. Like the 

full-size plane, this model will also be available with 

a self-launch system. 


September/October


Page 66: 

- Erwin Schreiber with the first “ASK-21” fuselage in 1:3.3 scale. 

- An important production step: tempering wings for a “Duo Discus-X.” 

- Fuselage production of a “Duo Discus-X:” spraying gel coat into the mold. 


- 37 - 


Page 67: 

- Rounding out the options are high-quality bags by TJ-Flächentaschen. 

- Accessories and components are sorted to assure efficient production and spare parts delivery. 

- Erwin Schreiber proudly presents the impressive fuselage of the “OMF 100-160 Symphony” tow plane. The model 

consists of 31 molded parts. 

- The most successful model of the firm is the “Duo-Discus X” in 3.3rd-scale. 

September/October

Aerobatic Monster 

“MDM-1 Fox” in 1:2 Scale by Paritech 

The first “Fox” I bought was 3rd-scale with a 4.6 meter 

wing span and a flying weight of about 16 kg. The 

plane was barely half-done, when my college Paal 

Vindfallet showed up and told me he wants to buy the 

plane from me. He finished it, but I of course had to 

buy my second “Fox,” this one 2.5-scale made by 

Bruckmann in Austria. I flew this plane for about two 

years until Paal wanted it too and picked it up at the 

meet of the Swedish IGG in Alleberg. There I was Foxless 

once again, but I had caught the acro-bug, and so 

I ended up burning the money earned from the sale of 

#2 by buying “Fox” #3. Big time, literally, because I 

chose the half-scale version by Paritech. Just as soon 

as the model arrived in a humongous crate, I started 

assembly. Unfortunately, this model early on disappointed 

me somewhat due to several issues: 

The nose cone (from canopy to tip) is made to be removable. 

That’s quite practical, because the cone-less 

fuselage is just as long as the wing halves. But I 

thought the seam looked ugly. Also, the cone had a 

lump on the top, and it didn’t look like the photos of the 

original. I also thought the fuselage tip was too round, 

possibly due to safety issues? I fiberglassed the cone 

to the fuselage and faired it in with putty. I reshaped it 

with thickened epoxy and made it longer and more 

pointy. Now it was time to fill and sand, fill and sand, fill 

and sand… until I liked the result, at which time I 

dropped it off at a body shop to get it painted. 

The hinges on the right side of the canopy where made 

from 4-mm brass tubing, and they stuck out on the 

fuselage side. I just couldn’t look at that, and thus another 

change happened. I replaced the factory hinge 

with a more classic one, which also happens to look 

closer to the original. My good buddy Atle Viken silversoldered 

3-mm brass tubing onto brass plates, which 

were bent and epoxied into the fuselage and the canopy 

frame. This solution to me is stronger and more 

functional. 

The latches on the left side of the two canopies were 

the well-known ones made from brass with springloaded 

steel pins. To me, they seemed a bit flimsy for 

this mighty “Fox,” particularly because the rear canopy, 

when latched, could move aft about 10 mm. Imagine 

what could happen at high airspeed. Because I really 

didn’t want to find out, I had to find better latches. Paritech 

sent me a drawing with instructions for a scalelike 

solution. This required to fill the hollow canopy 


- 38 - 



frame with thickened epoxy where needed. Also, 6mm 

steel pins where epoxied into the frame at the 

bottom. 

The elevator control horn was made from anglealuminum 

and a 3-mm pin to which the two elevator 

servos were to be linked. The alu part was attached 

only to the bottom skin with two 3-mm bolts. But on 

a model this big, all control horns — especially the 

one for the elevator — should be fastened very 

thoroughly, because G forces, positive and negative, 

can be significant. I decided not to use the alu 

part, and instead fashioned two control horns from 

3-mm fiberglass material, which went all the way to 

the top skin and were epoxied to factory-installed 

ribs. I drilled holes into the horns before installation 

to allow resin to flow in and assure a secure joint. 

While outfitting the fuselage, I noticed that the factory-installed 

former under the rudder was glued 

only to the left side. You could see that quite well, 

even from 2 meters away, by shining a light down 

the inside of the fuselage. It was quite a chore to 

epoxy this structurally important former to the right 

sight of the fuselage. In the worst case, torsional 

forces could rip off the tail section if this former 

didn’t hold. Only with a significant effort did I manage 

to eventually get thickened epoxy between the 

former and the fuselage. 

The included main wheel was too small for my 

taste. I also thought the wheel brackets were not 

glued well enough into the fuselage. I cut them out 

with a rotary tool and installed a bigger, scale-size 

wheel assembly with disc brake made by Modellbau 

Josef Eichstetter (www.eichstetter.de). I built an 

inside wheel cover from 3-mm plywood, which I 

painted. 

Time to install the servos: 

Elevator: 2x Hitec „HS-5955TG“ 

Rudder: 2x Hitec „HS-5955TG“ 

Aileron: 4x Hitec „HS-5955TG“ 

Tow Release: 1x Hitec „HS-5955TG“ 

Spoilers: 2x Hitec „HS-5965MG“ 

Wheel Brake: 1x Multiplex „Power digi“ 

Like the original, each wing half has two ailerons 

with a servo for each. For the rudder, I ganged up 

two servos mechanically; I installed them above the 

September/October

wheel. The rudder is actuated by steel cable using two 

pulleys. This looks good and works beautifully. The 

elevator really should have two halves, each with its 

own servo. I chose not to do that for practical reasons, 

and so two servos simultaneously move the one-piece 

elevator on my “Fox”. Lastly, I installed the servos for 

the tow release and the wheel brake. The brake cylinder 

and its servo sit under the rear seat. 

When several control surfaces are moved simultaneously 

in such a big plane, aerodynamic forces and 

current consumption are high, particularly during aerobatic 

maneuvers. To assure sufficient and secure 

power, I installed the “Easypatch 12-2 ESX” module by 

UA9 (www.ua9.de). This system satisfies all needs of a 

big glider, and it has been used successfully for years 

by fellow pilot Remi Willassen. Accompanying the 

module is a Multiplex 12-channel IPD receiver and two 

5-cell 3,000 mAh NiCd packs. That ought to do it. 

I mounted the tail wheel and its covers before I started 

with the cockpit detail. First, I reinforced the seat 

backs. To fasten the head rests and the seats, I followed 

the advice of flying college Andy Schäfer from 

England. Like with many large scale gliders, the “Fox” 

requires some creative thinking to solve technical 

tasks. It’s become tradition to use instruments and 

scale pilots from the fine shop of Axel Pfannmüller 

(www.axels-scale-pilots.de). My big “Fox” was no exception, 

but this time everything was a bit bigger and 

therefore more expensive. 

After painting the seats and the cockpit insides, I put 

the plane on the ballast stand. It needed two kilos of 

nose weight, which actually was less than I had calculated, 

given the large amount of paint needed for the 

fuselage. Now I was looking for decals of an original 

“Fox,” which ideally had hardly or never been used on 

a Fox before. That wasn’t easy, because most originals 

had been modeled already. Paritech offered three 

alternatives, and I chose the Swiss one “HB-5960.” I 

hadn’t seen that before on a full-size “Fox.” With the 

help of my friend Petter Östbye, who has good connections 

to Switzerland, we found out that “HB-5960” had 

not been assigned to a “Fox”. 

Gladly, I found another solution: Because I kept in 

contact with Axel Pfannmüller since I had ordered the 

scale pilot, Axel asked me which decals I had chosen 

for my “Fox.” “None,” I answered. So he spontaneously 

suggested to design one for me, and shortly thereafter, 

he had a nice suggestion for me: he had combined the 

Aresti symbols, the Norwegian flag, and my initial “GR” 

in the design. I was thrilled! 

My friend Frank Traut from Velbert plotted the decals. 

Shortly before Christmas, Frank and his girlfriend delivered 

the decal set to Norway. Applying the decals 

was very challenging and time consuming, but Axel’s 

work was excellent, and everything fit the fuselage as if 


- 39 - 


he had had it for a template. All decals were applied 

with water and a drop of dish soap and were 

smoothed with a plastic squeegee. 

After programming the model, I headed to the Haga 

International Airport two days before Christmas in 

minus-2 degrees centigrade. Tow pilot was Oddvar 

Kristiansen, and his “Yak-55” with a 400-cc “Moki” 

radial engine pulled the big “Fox” to altitude, no 

problem. I released at about 450 meters altitude 

and tested the rudder first: works just fine and has 

good authority. Now ailerons: the mighty “Fox” did 

not hesitate and followed my commands precisely. 

Let’s do a 45-degree dive to check CG (200 mm 

behind the leading edge). It became obvious, that 

the “sissy lead” wasn’t needed and could be removed 

from the nose of the aircraft. Still I decide to 

try inverted flight. With a little forward stick, the 

“Fox” flew as if on rails. I still had plenty altitude, so 

I added a few rolls. 

Time to set up for a landing. The pattern has to be 

flown big with such a plane. Apply spoilers… oops, 

in all the excitement, I had forgotten to check for 

pitch change while still at altitude. Too late now! 

The “Fox” dove for the ground, but a good pull on 

the elevator stick brought the situation back under 

control. I greased the landing, and the “Fox” steadily 

rolled to a stop. This maiden flight once again 

was a special and unforgettable experience. 

The days are short here up north this time of year, 

so I got only 4 more flights in. After New Year’s, I 

flew again a few times at Haga Airport. I really liked 

the way the plane flies and I could not detect any 

negative attributes. I removed the ”sissy lead,” installed 

acid-free oil in the brake cylinder for the 

main wheel, and reduced aileron differential by 9 

percent. 

In late May, I trailered the plane to Alleberg for the 

big IGG meet. Alleberg is something like the Swedish 

Wasserkuppe, and it is close to Fallköping between 

Lakes Vännern and Vättern. It took me 4.5 

hours to get there from Oslo. After several flights, 

there was this good feeling that I got to know the 

plane better and better. I tried rolls, inverted flight, 

and hammerhead turns. Long story short, the “Fox” 

will do anything that is possible in aerobatics. The 

wheel brake really helps roll-out on landing. 

After many extensive flights, all I can say is that 

Paritech’s “Fox” convinces with excellent flight performance 

and characteristics, and that not just for 

aerobatic flight. Energy retention simply is enormous. 

Kit quality is fine,except for the issues I’ve 

described, as is surface quality. The plane is plenty 

strong enough. People in countries with weight 

limitations may want to keep an eye on the all-up 

September/October

weight. But staying under 25 kg is possible depending 

on cockpit detail and other accessories. 

By the way, Paritech offers a building service for this 

model. For example, they’ll install the landing gear, 

Data 

“Fox” by Paritech 

Fully-molded Aerobatic Scale Glider 



Fling Weight: 32 kg 

Area: 300 qdm 

Wing Loading: 106,67 g/qdm 

Wing Airfoil: RG-15, 12 % 


- 40 - 


mount the canopy, hook up control surfaces, and 

install spoiler caps. Paritech also offers a cockpit kit 

and other accessories for its “Fox.” 

Gunnar K. Rokseth 

Price starts at 3,990 Euro; Paritech, Germany, Tel. +49/7276/918013, www.paritech.de. 


Page 68: 

- Ready for take-off. AUFWIND author Gunnar Rokseth (left) with his new “Fox” by Paritech. 

Page 69: 

- The nose cone is removable for transport reasons. But I glued it on and and reshaped it to be more scale like. 

- The hydraulically-braked wheel adds a lot of safety, especially with such big models. 

- The cockpit is the result of countless hours. The pins for holding the canopy closed can be seen integrated into 

the canopy frame. A nice detail: the aerobatic program on the instrument panel is right in the pilot’s field of view. 

Page 70: 

- Coming out of a dive, the model performs impressive low passes. At 32 kilos, energy retention is enormous, great 

for aerobatics. 

Page 71: 

- Unmistakably “Fox.” It’s a real looker with the Arresti decals designed by Axel Pfannmüller. 

- Majestic is a good word to describe final approach of the “Fox.” The big landing gear by Eichstetter offers good 

ground clearance. 

- The Polish aerobatic 2-seater has been modeled in many sizes. Paritech’s “Fox” is breathtaking with its 7-meter 

wing span. The design is by Holger Höchsmann. 

- The scratch-built canopy hinges have held up fine in everyday use. 

September/October

One Step Further 

Step-Four Introduces a new Version of its Milling Software 

(Note to English readers: for this article, I lack the 

technical vocabulary and knowledge. I will translate as 

well as possible, but leave some original German terminology 

in the text and mark it like this example: (??, 

G = Setzen von Stegen). I apologize for the inconvenience. 

- Dieter Mahlein, translator) 

Step-Four has launched version 2 of its “XpertMILL” 

software. Working with users, the company has added 

many new features, such as the eagerly awaited positioning 

of spacers (??, G = Setzen von Stegen). Even 

just the base version of “XpertMILL V2” offers many 

new features: 

- There is better visualization during 3D-milling, because 

STL volume data can now be imported. 

- Data can now be read- or write-protected and unprotected 

again. 

- The new teach-in function allows the duplicating of X- 

, Y-, and Z-coordinates of existing parts and the reworking 

of their outlines. 

- For complex parts, up to 65,000 milling levels can be 

set up, the first 256 of which can be pre-defined in 

regard to label, color, line width, and line type. 

- For users needing exact time tracking for their work, 

the new version has built-in timers for programming, 

machining, and tooling. 

The industrial version of “XpertMILL” also has been 

updated, and it now allows the assignment of object 

parameters to levels. CAD software often is used before-hand 

to divide milling data into levels. For example, 

inner outline on level 1, outer outline on level 2, 

pockets on level 3, drilling on level 4, and so on. If, as 

is common, one part needs to be made over and over 

maybe with a few changes here and there, all milling 



- 41 - 



parameters (for example outline, tool, milling depth, 

material thickness) can now be applied to every 

level, which significantly reduces set-up time. Other 

features are: 

- Support for length-checking switch and measuring 

plate and pen (??, G = Längentestschalter, Messplatte 

und Messstift) is now included. 

- On the monitor, color for work area, selection, 

machine, object outline, and background can be 

altered and thus allow optimal and individual adjustment 

to the computer and monitor. 

- Object outline and labeling can be pre-selected 

- Remote function 

- The formerly optional add-on module “Xpert[3D]” 

is now integrated in the basic version of “XpertMILL 

V2.” 

Add-on modules have also been updated: 

“Xpert[DRAW]” now has a better text editor which 

allows alignment of multi-line text. The function 

AutoText with serial number function is now included. 

Further, “Xpert[DRAW]” can now generate 

3D spirals and offers multi-point addressing (??, G 

= Multipunktbearbeitung) and an improved smoothing 

function. 

For version 2, the optional expansion module 

“Xpert[CAM]” now offers positioning of spacers (??, 

G = Setzen von Stegen) without having to make 

changes to the object. 

Prices and purchase at Step-Four, Austria, tel. 

+43/662/4593780, www.step-four.at. 

Editorial Office 

- Milling data can be read/write protected and unprotected with a password. 

- Long awaited by users: the CAM module now allows positioning of virtual spacers. 

- Label, color, line width, and depiction can be pre-defined for 256 levels. 

September/October

Summer‐Highlight 

14 Years “Flying Circus” 

In the model airplane scene, Fiss and Flying Circus are 

always mentioned in the same sentence. I’m reflecting 

on this year’s event, which unfortunately was marked 

by low clouds, rain, and low snow lines in the Alps with 

snow covering the Möseralm and the Schönjöchl. But 

Gerd Holzner’s organizing team still pulled off the 

event quite well: Despite cold fingers and low snow 

lines, quite a bit of flying happened at the Schönjöchl. 

Remember the first Flying Circus? It happened July 

11-14, 1996. Fourteen years of this event is an accomplishment 

which warrants a review, I think, especially 

in today’s hectic world, where we forget so easily. 

Who, when launching at the Schönjöchl today, remembers 

the difficulties and prejudices facing Gerd 

Holzner and Ralf Scheifele? Or how much convincing 

was needed, and how many rocks had to be cleared to 

get to where we are today? Back then, it took just one 

year from idea to first event. In eight meetings with the 

officials in Fiss and the members of the tourism committee, 

ideas were discussed and firmed up and goals 

and structure of the event were finalized. Originally, it 

was planned to have the Flying Circus be a traveling 

show with events in various locations. But, as so often 

in life, things don’t go as planned, and the event stayed 

in Fiss. Difficult was the search for the first sponsors. 

The Flying Circus event had a booth at the 1996 Intermodellbau 

fair in Dortmund. Shortly thereafter, 100 

pilots had signed up. But it still snowed the weekend 

before the event, when the big vendor tent was supposed 

to go up; only later did the sun come out. The 

concept of alpine soaring, combined with vendor presentations, 

fun and partying, and evening shows (even 

with a fashion show), was a success. Early apprehension 

and skepticism made way for excitement and 

welcoming gestures. 

What else do I remember of 14 years flying circus? 

Crazy weather, alternating snow and sun. Excellent lift 

in some years when barn doors would have gone up. 

But also hours of (in the end successful) struggles 

finding thermals, especially by Uwe Gewalt and Theo 

Arnold. Spectacular landings way down in the valley 

near Fiss. And of course the unforgettable and humorous 

comments by Michael Schellberg, particularly during 

the night flying in down-town Fiss or at the pond in 

Ladis. The planes have grown up in recent years. In 

the beginning, gliders with 6 to 8 meter spans were 

rare. All-composite models are now common-place. 

We’ve seen extraordinary models fly, such as dinosaurs. 

An average of 150 registered pilots participated 


- 42 - 



over the years. Remarkable also was the 10th annual 

event in 2005 coinciding with Tangent’s 25th 

anniversary. And of course the many friendships 

forged between pilots from all over the world. 

How have Fiss and the surrounding area changed 

over the years? They became more tourist-oriented, 

particularly for winter recreation. New ski lifts and 

downhill runs were built, along with new hotels and 

bed-and-breakfasts. For example, the new Almkopfbahn 

opened the Urgtal region to winter recreation. 

A gondola service to the Schönjöchl opened in 

2004. The Restaurant “Berg Diamant” started offering 

gourmet meals and excellent views of the Tyrollean 

mountains. A new gondola service opened 

also to the Möseralm, where facilities for many 

summer activities have been installed. Model airplane 

pilots are now common and welcomed guests 

during the summer months. And flying on the 

Schönjöchl and the Perdatscher Bichl remains a 

special experience. 

But enough reflection, how was it this year? Again 

there was an impressive number of participants and 

spectators. And many vendors showed their latest 

wares. 

- Graupner was there with just about its entire line 

of RC gliders and related accessories. All models 

were equipped with its 2.4 GHz-IFS-System. CEO 

Stefan Graupner proudly showed off the latest digital 

servos. Graupner even added a special Flying 

Circus edition to its newsletter “Graupner Aktuell” 

and published it on the internet. It includes a video 

of the event. Using buddy boxes, interested pilots 

could test-fly models at the Schönjöchl, the new 

“Kult Mini Quattro,” for example. The Graupner 

Team, including Guntmar Rüb, Heiko and Oswin 

Greiner, and Steffen Wiesner, answered questions 

about Graupner products. Steffen flew the new 

small “Discus-2cT with 3.3-meter span. 

- TUN-Modellbau showed a strong presence. Ueli 

Nyffenegger brought is latest large scale gliders. 

Really impressive was the 2.5-scale “Duo-Discus.” 

TUN pilot Marco Mani did not risk a flight in the 

inclement weather, however. A highlight was the 

prototype of the new “Antares” (see AUFWIND 

5/2009) in 3rd-scale (6.66 meter span). This model 

of the 20-meter electro glider by Lange Aviation is 

built by Jiri Baudis, and it put on a great show with 

September/October

its high-aspect ratio wings. Ueli also flew his “Nimbus- 

4M” with self-launch system (wingspan 10.6 meters). 

- Robbe showed its new line of “Fiber Semi-Scale” 

gliders. A set of molded wings is used in conjunction 

with a variety of fuselages to yield models of a “DG- 

808C,” an “ASG-29,” a ”Ventus” or a “ASH-26.” Using 

different winglets, wingspans range from 4.17 to 4.25 

meters. Also shown was the “Cloud-Dancer,” a purpose 

built model with 4.1 meter wingspan. 

- Blue Airlines showed its 3.5-meter “Solo-Fox,” 

among other models. 

- Stefan Höllein flew the prototype of his new “Thermal 

Instinct.” This light-weight plane with 2.85 meters 

wing span has a wing loading of only 30g/qdm and a 3piece 

wing with carbon-tube spars. Unbelievably, the 

instinct failed, and the plane ended up landing out of 

sight; fortunately, it remained undamaged. 

- Multiplex brought all of its Elapor planes and for the 

first time showed its new 2.4-GHz-FHSS system. 

Photo captions: 


- 43 - 


Apropos 2.4 GHz: About half the participating pilots 

used the new technology. There also were a lot 

more foam planes flying than in years past. The 

night-flying at the Möseralm and the pond flying 

again were designed to be pure fun. In Ladis, 

Robbe’s Dirk Nething created the new contest “Pavillondurchflug” 

(fly under the canopy). Also in 

Ladis, night-time foamie aero-tow entertained the 

crowd. A fire works show at the Möseralm ended 

Friday’s festivities. 

Sunday started with blue sky, but it quickly became 

overcast. Show pilot Theo Arnold ended up flying 

his “ASG-29E” in the rain at the Schönjöchl to allow 

the camera team of Modellfliegerkanal to do some 

more filming. There is a nice video of Flying Circus 

2009 posted on www.modellfliegerkanal.de. 

To sum up, the 14th annual Flying Circus once 

again was a special experience, which is unique in 

the model airplane scene. The Flying Circus in Fiss 

has been and always will be a meeting of friends at 

a friend’s place. 


Page 74: 

- The newly formed Graupner/Tangent team, including Guntmar Rüb, Heiko and Oswin Greiner, and Steffen Wiesner, 

answered questions about Graupner products. 

- An unusual view of the launch site (above) of the Flying Circus. The terminal of the new Almbahn (2,600 m elevation) 

sits high above that of the Schönjochbahn. 

Page 75: 

- Graupner’s new “Discus-2cT” with 3.3 meter span should become quite popular. 

- This LS8-18 by HE-Faserverbundwerkstoffe flew at the Flying Circus event. 

- TUN-Modellbau’s scale glider always attracted a crowd. Unfortunately the big “Duo-Discus X” did not fly. 

- Robbe showed its new line of all-molded modular gliders of the 4-meter class. 

Page 76: 

- Premiere in Fiss. The new 3rd-scale “Antares” by TUN-Modellbau (wing span 6.66 m). 

- Show pilot Theo Arnold ended up flying his “ASG-29E” (wing span 7,2 m) in the rain at the Schönjöchl to allow the 

camera team of Modellfliegerkanal to do some more filming. 

- Stefan Höllein flew the prototype of his new “Thermal Instinct.” Unbelievably, the instinct failed, and the plane 

ended up landing out of sight; fortunately, it remained undamaged. 

- Guntmar Rüb launching the new Graupner/Tangent “Alpina 5001”. 

- Bad weather, but full house! 

September/October

F3B‐WC 2009 

(…from the Austrian perspective) 

Germany wins ahead of Switzerland and Austria 

Four weeks before the F3B world championships, a 

F3B Eurotour contest took place at the Ivancice flying 

site near Brünn. This site had just been opened and 

dubbed “Czech Heaven”. A 150 meters long and 10 

meters wide runway, about 30 piled up containers, and 

really nasty check fences had been financed with 

European Union funds — according to the entrance 

sign. Grass had just been sown also. It took the local 

contest director two full days to fly two rounds with 60 

competitors. There were difficulties with the transmitter 

impound; once channel 67 was issued three times 

simultaneously. Thus, several models came careening 

to the ground. On Sunday, cars were broken into in 

broad daylight — by then many soon-to-be world 

championship competitors were worried about organization 

and safety. 

Friday, July 31: travel and training day. — Compared 

to the Eurotour contest four weeks earlier, many 

changes had been implemented. Roman Vojtech was 

employed as deputy contest director, which instantly 

had a positive effect on the organization. The contest 

director of the Eurotour, and now for the WC, did his 

job enthusiastically, which kept damage during the WC 

at a minimum. After the training day, his team was well 

prepared for the world championship. There were significant 

changes to the flying field also. The neighboring 

grain crops had been harvested, and the area between 

the winches covered with a fleece fabric to avoid 

the morass we had in Switzerland two years ago. 

Model check-in was minimal: only the nose radius and 

the tow hook were closely inspected. A sticker was 

placed on each removable airplane part for the purpose 

of policing and preventing the illegal changing of 

parts during a round. Two official metering units for 

winches were available, with which competitors could 

check their winches before the contest. 

Saturday, August 1: World Cup and Zero-Round. — 

The weather was excellent, hardly a cloud in the sky, 

and light easterly winds. We started with duration 

which caused no major problems. However, landing 

was on a harvested grain field with straw strewn about, 

which allowed the gliders to slide a ways, and thus 

there were some low landing scores. Weak thermal 

activity made the speed task difficult. And the course 

was set up backwards, which didn’t help the results. 

Times were between 15.38 seconds (Andreas Herrig) 

and the high 19s. The distance task completed the first 

round. The score board was again set up in the pilot’s 


- 44 - 



line-of-sight, which meant the models disappeared 

behind it toward the end of the flight (...this is unsafe, 

particularly when the models are being flown 

near stall speed). Highlight of this distance round 

was 34 lengths flown by Craig Goodrum and Jiri 

Baudis while there was a thermal on course. But 

generally, the top pilots had good flights. The zero 

round was interrupted at 5 PM for the opening 

ceremony, which was kept to a tight schedule; the 

speeches were short. After playing the FAI and the 

Czech national anthems, Thomas Bartovsky — in 

his capacity as Chairman of the Jury — declared 

the world championship as opened. After the ceremony, 

we flew the distance task of round 2 of the 

pre-contest. 

The first team managers’ meeting was held that 

evening. It was supposed to be short, but some 

concerns had to be addressed: 

- Why is the score board positioned in the line-ofsight 

during distance? 

- The western part of the airspace was now closed, 

because planes ended up flying over a road. 

- Belgium and Switzerland demanded that, complying 

with still valid rules, a 20 kHz frequency spacing 

be maintained; Roman was going to decide this by 

next morning. 

- After some discussion, a fifth helper was allowed 

during cross-wind conditions; but he was supposed 

to only tend to the line at the turn-around. 

- The number of winches allowed was set to six per 

team. This opened the question, what does the 

current world champion (Martin Herrig, Germany) 

launch with? It was agreed that the German team 

with Martin Herrig may use eight winches. 

- The Jury was to decide on a case-by-case basis, 

when, during speed rounds, the field gets divided 

into three groups, and groups can repeat. 

Sunday, August 2: Contest starts at 8 AM. — The 

second day of pre-competition started with the distance 

task of round 2. The following speed task saw 

improving thermal conditions and increasing head 

wind during launch. Ronald Henninot flew the fastest 

time at 13.88 seconds, followed closely by four 

pilots with 14-second times. The pre-competition 

event ended at 1 PM. Winner was Martin Herrig, 

with Andreas Böhlen (Switzerland) coming in second, 

and Joe Wurts third; Joe flew for New Zealand 

September/October

this time. The second team manager’s meeting 

brought some changes: 

- A new launch sequence had been set up to keep the 

20 kHz frequency spacing. This resulted in frequency 

collisions in consecutive groups and less randomness 

in the flying sequence. 

- The score board was now on the west side of the 

field and no longer in line-of-sight during distance and 

speed tasks. 

- While discussing safety zones, it was agreed to allow 

speed flying in an unlimited area north of the safety 

line, and landing in a small area between winch lines 

and spectators and an open area south of the container 

village. 

In the evening, as forecast, a narrow cold front rushed 

across the area with lightning, thunder, and storm 

squalls. The power grid collapsed, and all of Ivancice 

went dark. 

Monday, August 3: First WC day. — The cold front had 

damaged several tents, including broken poles in the 

host facilities, such as the transmitter impound; some 

technical equipment also was damaged. 

Round 1: Most damage had been fixed by 10 AM, and 

we were flying. Duration was first. The only points lost 

were during landing, because planes were sliding unpredictably 

on the straw. The distance task was divided 

into groups of four or five pilots each. Under 

weak thermal conditions in the morning hours, few 

points were lost, and on average less than two lengths 

separated the competitors. The speed task followed 

the official launch sequence: Hans Rossmann flew a 

15.52 second time and was leading for quite a while 

until Daniele Amici got a 15.34. At the end of round 1, 

Andreas Herrig led before Andreas Böhlen and Hans 

Rossmann. 

Tuesday, August 4, Round 2: The thermal task started 

at 8 AM sharp. All made their 10-minute time in the 

calm air, but a few rain showers interrupted the distance 

task. As during the previous day, most flying 

happened at the north side of the field. The wind was 

almost due north. Good launches required wide swerving, 

almost perpendicular to the launch direction, to 

extract the most energy from the available wind. 

Round 3: Because rain was threatening, the contest 

management decided to fly distance first. The top pilots 

from Germany and Switzerland remained in the 

lead. When the weather cleared a bit in the afternoon, 

the speed task of round 2 was made up. A rain shower 

hit at the end of the task, and the Jury had some difficulty. 

At first, they stopped the task ahead of pilot 

Joachim Stahl, then resumed after the shower had 

passed. Joachim was not thrilled, because in the team 

managers’ meeting it had been agreed to have the 

whole group repeat after an interruption. After a lot of 

back and forth, the field was divided into three groups, 


- 45 - 


and the third group repeated the speed task. This 

resulted in three group winners, all with times between 

14.9 and 15.2 seconds. 

Wednesday, August 5th: It looked like a nice summer 

day with good thermal activity. But during duration, 

almost one quarter of the pilots did not make 

their time and gave up points. The speed task still 

needed to be flown to complete the first three 

rounds. Russian competitor Tvorogov flew a 14second 

time, and all top pilots stayed close: Martin 

Herrig, 14.74; Peter Hubbertz. 15.21; and Christian 

Müller 14.78. Andreas Böhlen won with the task 

with 13.83 seconds. 

Round 4: The speed task continued without interruption, 

and Swiss competitor Christian Müller won 

this time with an excellent 14.38 seconds. Given 

their speed task wins in rounds 3 and 4, the Swiss 

definitely were having a come-back after some 

botched distance flights. The distance task of round 

4 started early afternoon during good thermal conditions. 

But the number of flown lengths was hampered 

by a fairly strong cross wind. A signal mix-up 

happened in the strong group consisting of Jürgen 

Pölzl, Andreas Herrig, Christian Müller, and Joe 

Wurts. This affected Andreas the most, and the 

German team issued an official protest, demanding 

a re-flight. While the Jury deliberated on that, the 

duration task finished round 4. 

Round 5: The calm air in the evening yielded distance 

results varying from 16 to 27 lengths. In this 

type of air, launch height is of particular importance, 

and again the top pilots prevailed. 

Thursday, August 6: the remaining groups flew their 

distance task, and a duration task followed without 

much change in ranks. The speed task was more 

interesting: Evgeny Tvorogov took the 1000 with a 

flight of 14.18 seconds, but the overall leaders 

managed to stay close with times between 15 and 

16 seconds. 

Round 6: The distance round started by re-flying 

the fourth group of round 4. The jury had spent the 

evening to analyze video and listen to witnesses 

and pilots. The German protest was upheld. Andreas 

Herrig capitalized on this decision only in part 

by scoring over 950 points with one length less than 

the group winner. The wind was from the northeast, 

and varied between 2 and 8 meters per second (5- 

18 mph). Fast-moving cumulus clouds changed 

thermal conditions almost second by second. The 

results reflect these rapid changes in that group- 

1000s were flown anywhere from 12 to 31 lengths. 

Martin Herrig gave up one length and landed in a 

bush on the lee side of the field. He did not receive 

a penalty, but the tail had to be repaired before the 

next task. The varied conditions also affected the 

September/October

speed task results: there were 10 times under 15 seconds, 

but an unusually high number of top pilots flew 

slower than 17 seconds. Duration ended the thermal 

lottery and the day without many problems. 

Suddenly it was Thursday night and about time to have 

a look at the overall standings. Not considering a 

throw-out round, they were: 

1. Herrig, Martin GER 17.591,85 

2. Böhlen, Andreas SUI 17.545,71 

3. Herrig, Andreas GER 17.493,47 

4. Hubbertz, Peter GER 17.449,03 

5. Müller, Christian SUI 17.336,12 

6. Weberschock, Martin GER 17.240,64 

7. Väisänen, Pasi SWE 17.161,36 

8. Amici, Daniele ITA 17.008,08 

9. Henninot, Roland FRA 16.856,10 

10. Smith, Mike USA 16.825,86 

Pretty tight results for sure; the speed task alone could 

make or break the champion title. Not to mention penalties… 

Team standings looked as follows: 

1. GER 52.183,14 

2. SUI 51.552,07 

3. CZE 50.371,21 

4. AUT 50.024,50 

5. ITA 49.352,74 

6. SWE 49.345,70 

Germany and Switzerland had distanced themselves 

from the field and secured their standings. The race for 

3rd place was still interesting, however, with the Czech 

and Austrian pilots still having good chances. 

Friday, August 7; final day and round 7: Roman set the 

starting time to 9 AM, and thus the day started a little 

more relaxed. The key, of course, was distance. Unfortunately, 

Peter Hoffmann missed his change to make 

up points to the Czech team by losing to Andreas Herrig 

by three lengths. Hans Rossmann also lost points, 

so Austria only could hope that the Czech pilots also 

would give up points. But the Austrians also had reason 

to celebrate: Jürgen Pölzl’s last distance task 

ended like all others he had flown during the event: he 

won again! He clearly was the king of distance of this 

world championship. 

During launch of the next to last group, a plane 

crashed at the starting line and hit an Australian helper 

at the hip. After initial first aid, emergency services 

from Ivancice had arrived. Nobody wanted to fly anymore, 

the extreme cross-wind launches had claimed a 

victim. That the model involved was a Spanish one did 

not matter. Likely it was a gust which pushed the pilots’ 

skills to the limit during launch. Roman ordered a stop, 

and the contest was resumed and finished only after 

good news were received from the hospital. 

The Herrig brothers each got 1000 points, Andreas 

Böhlen lost by one length, and Peter Hubbertz by 


- 46 - 


three. Regarding team standings, Jiri Baudis lost by 

five lengths. This brought Austria back into contention. 

The wind had picked up before the start of the 

duration task, but a few cumulus clouds indicated 

that lift was still to be had. Peter Hoffmann even 

ballasted up, in case there was need to come home 

from a downwind thermal. From the Austrian team’s 

perspective, Hans Rossmann and Jürgen Pölzl 

absolutely had to improve upon their poor duration 

scores for a chance to pass the Czech team. Hans 

Rossmann had no problems. He caught a small 

thermal and drifted along with it. The first hurdle 

had been taken. Jürgen made it much more interesting: 

he drifted way south in a really weak thermal. 

It stayed dramatic until, while constantly 

searching for lift, the ten minutes finally ran out and 

his “Freestyler” had landed at the spot. The team 

managers’ calculators ran hot as if one could make 

the commencing speed tasks go faster or slower. Is 

it possible to relax knowing that “all” one has to do 

is fly the speed task faster than 15 seconds? 

The speed task was flown in the initial launch sequence, 

not in reverse order of pilot standings. This 

speed round was the biggest chance for the the 

Austrian team: Peter Hoffmann was hoping to better 

his 19.43 seconds of an earlier round, and Jürgen 

Pölzl his cut from round 3. Martin Herrig launched 

immediately ahead of Peter. His first launch only 

got him to a medium altitude, so land and repeat. 

The second launch looked even worse, the weather 

was uncooperative. Martin flew 15.75 seconds in 

light sink, which wasn’t thrilling for a candidate to 

become repeat F3B world champion. Peter Hoffmann’s 

working time was running: Having observed 

Martin, he knew the weather was not ideal at the 

moment and waited a minute. Again, he had to veer 

off at almost 90 degrees to grab some head wind 

and build pressure under the wing. On course, the 

weather looked a little better. So, come down fast 

and relaunch. One-and-a-half minutes working time 

left...don’t pop off. The model launched cleanly, 

veered right, and the zoom looked much better. 

Peter didn’t lose much altitude before entering the 

course. Back to base A, dive, and enter. He was 

happy with 16.01 seconds, because this flight 

added 150 points to the Austrian team score. 

Peter’s team mates flew almost immediately. Jürgen 

caught really good weather, and dove almost 

immediately toward base A; fast turn at base B, 6.8 

seconds back to base A — the model seemed to 

not slow down. The second base B turn worked 

perfectly, and he flew 14.9 seconds. That was the 

best time at that moment, and it really helped the 

Austrian team. Hans made a flight in the low 16s 

and added almost another 100 points to the team 

score. Now, the Austrians could only wait and see 

how the Czech team was faring and keep a close 

eye on the individual standings. 

September/October

Czech pilot Petr Fusek definitely needed a good flight, 

because he already had two slow times in speed. He 

flew cleanly, about 16 seconds. It was calculated that 

Jiri Baudis, the last pilot to fly for the Czech team, 

needed a sub-13 time to keep the team in the running 

for third place. Jiri launched with the northerly crosswind, 

which had been blowing since day 1. Jiri flew his 

model “Cyril” and got a 16-second time in neutral air — 

not enough for the Czech team to reach 3rd place. 

In the individual contest, Martin Herrig had flown 15.75 

second time — not very pleasing for him. A little later, 

his brother Andreas managed 15.89 seconds. In the 

morning, Andreas Böhlen was one length slow during 

distance, so he needed a very fast time. He flew 15.05 

seconds, maybe not good enough for a spot on the 

podium. Christian Müller also flew a low 15-second 

time, but Peter Hubbertz used excellent weather to fly 

the event’s best time of 13.76 seconds. 

After some calculation, the final result was: 

1. Martin Herrig, “Freestyler III” 

2. Peter Hubbertz, “Radical Pro” 

3. Christian Müller „Freestyler III“ 


- 47 - 


Team Standings: 

1. Germany (Andreas Herrig, Hubbertz, Weberschock) 

2. Switzerland (Müller, Andreas Böhlen, Stefan 

Böhlen) 

3. Austria (Pölzl, Rossmann, Hoffmann) 

After the last flight, all competitors formed a sort of 

guard of honor for the official helpers. Martin Weberschock 

called everyone by name, and they received 

much applause for their flawless performance 

during the seven days of flying. They also 

were invited to the evening party. 

Saturday, August 8: The awards ceremony was 

scheduled for 1 PM followed by the official banquet. 

Soon thereafter, an Austrian national F3B team 

stood on the podium for the first time in 16 years. 

And now, post-WC becomes pre-WC… 2011 most 

likely in China. 

Peter Hoffmann 

Photos: Gerhard Flixeder 

September/October

A Wolf in Sheep’s Clothes 

The “Elektro Trainer S” by Graupner 

New for spring 2009 and barely 1.2 meters in span, 

this model is meant for several applications: aerobatics 

trainer for intermediate pilots dabbling in this area; 

float plane with the included floats with water rudder; 

tow plane for small gliders and banners and candy 

bomber using the included tow release. 

The big box contains a cleanly and safely-packed 

wing, horizontal stab, two fuselage halves, two floats, 

and a blue canopy made from Solidpor. A small 

cardboard box contains small parts, instructions, 

drive train, and stickers. There is not one piece of 

wood in the entire kit! But everything is complete, and 

only the RC gear needs to be supplied. As an option, 

Graupner offers servos, LiPo battery, and charger. 

So my shopping list was rather short. The necessary 

gear should be ready before starting assembly to 

assure smooth progress. The recommended Graupner 

“C-231” servos were out of stock, so I used the 

proven Multiplex “Zebra ZS-F135” servos, which are 

similar in price and performance. Just the plugs are 2 

mm higher, but otherwise they fit perfectly into the 

receptacles in fuselage and wing. Because I wanted 

to test all applications of this plane, I also installed 

the tow release servo. 

Assembly of the model was accomplished quickly 

and easily with cyanoacrylate glue: you have to glue 

in the motor mount, the wing saddle, and the three 

servos (rudder elevator, and tow release) into the 

fuselage, then join the fuselage halves. The aileron 

servos and main spar are glued into the wing, and 

the slot for the spar and the servo wiring has to be 

closed. After making the control linkages and mounting 

the landing gear, the model was ready to fly. 

For use as a float plane, the extra gear mount has to 

be installed into the fuselage. The floats themselves 

only require two hard points each to be glued in. A 

water rudder is included, which can be interchanged 

with the tail wheel. 

But first I stayed on land and checked the performance 

of the drive train: for the maiden flight, I installed 

a new 3s 1,600 mAh LiPo-pack by Hyperion. The 

current measurements showed that this new little 

plane is quite powerful: 42.8 Amps static current 

promised above-average performance. One does 

have to be a little careful, because the controller is 


- 48 - 



rated to only 35 Amps and the 25C battery can deliver 

about 40 Amps. So, the warnings in the instructions 

should be heeded, and sufficient cooling should 

be assured when using a 3s battery. 

The maiden flight was as routine as expected. Takeoff 

at half-throttle, practically no trim corrections, and 

moseying around at quarter-throttle was child’s play. 

Full throttle transforms the little guy into a racer: vertical 

climbs and all aerobatics possible with a highwing 

plane are quickly accomplished, so the aerobatics 

trainer attribute is well deserved. Landing at the 

pilot’s feet also was easy, smooth, and safe. For the 

next flight, I installed a bigger 2100 mAh battery, 

which can be charged at 5C. While I don’t always use 

this charge rate, the battery has performed without 

complaints so far. 

Back to the “Elektro Trainer S:” low passes, upright 

and inverted, and the high-performance drive train 

are a lot of fun. So, on to aero-tow. First, I towed a 

“Highlight” 1.8-meter HLG weighing 400 grams without 

any problems whatsoever. After a clean rise-offground, 

the big HLG was towed smoothly to altitude; 

the Trainer barely noticed it, and towing a plane twice 

this heavy should be no problem at all. Next I towed a 

“Pirol” by Borjet almost vertically skyward. And the 2meter 

EPP “Fox” by Hype presented no problem 

either; it took only 40 seconds of a 30- to 35-degree 

climb to get to release-altitude. And after release, it’s 

really fun to call out “tug landing!” and dive nearly 

vertically toward the runway and land near where the 

next glider is waiting for its tow. 

Time to put the floats on. This was most exciting for 

me, because my float plane experience adds up to 

exactly 0. The switch took only 5 minutes, and I also 

packed my swimming trunks for good measure. I 

found a spot on shore where I could launch directly 

into the wind, and I set the “Elektro Trainer S” onto 

the water. It started taxiing at quarter-throttle, which 

was really easy with the water rudder; it felt almost 

like a boat. At full-throttle, the plane lifted off after 

about five to six meters. The flying characteristics 

seemed unaffected by the floats. For landing, I came 

in with motor off and touched down at a shallow angle; 

one small hop, and that was it. Taxi back to 

shore at quarter-throttle… I didn’t expect it to be this 

easy. 

September/October

I flew this plane a lot all summer long. It is eminently 

suitable for every-day flying. The drive train -- while 

pushing its limits – performs excellently and is fun 

also for experienced pilots. I even used the plane for 

beginner training; all I did is reduce the throws a bit 

on the trainer transmitter. If using only part-throttle or 

a 2s LiPo pack, the “Trainer” is great even for com- 

Data: 

“Elektro Trainer S” 

An allround plane by Graupner 

Wing Span: 1,200 mm 

Length: 950 mm 

Flying Weight: 940 g (3s 1,600 mAh) 

970 g (3s 2,100 mAh) 

add 150 g for floats 

Motor: „Compact 345Z“, Graupner 

Controller: „Brushless Control 35”, Graupner 

Propeller: 10x5“ 


- 49 - 


plete novices. By the way, the kit includes a bracket 

for the “FlyCam,” with which the camera is easy to 

mount, and aerial photos are easy to take. 

Stephan Fitz 

Photos: Bernhard Fitz, Dieter Lange 

Price: 149.95 Euro, 229.- (with servos, LiPo, and charger); available at dealers, www.graupner.de. 


Page 84: 

- Maiden flight at the lake: I’m not yet wearing my swim trunks. Will I need them? 

Page 85: 

- Everything is cleanly packed, and the kit is complete. 

- The servos are the first to be installed. 

- These are the extra parts needed for float flying. 

- The “Elektro Trainer” looks clean, modern, and racey. 

- The second landing gear mount is needed for the floats. 

- Just about to touch down – everything worked well. 

September/October

Training Unit 

“Epsilon” by Staufenbiel 

This new model is introduced as a F3J trainer. This 

glider features a 3.5 meter wing span, a carbonreinforced 

fiberglass fuselage, and built-up wings. The 

wings are built carefully to nearly achieve the typical 

planform of molded F3J gliders, which makes the 

model look modern and professional with its nice plastic 

winglets. Modern F3J gliders are are extremely light 

and strong, and as a result, also quite expensive. Exotic 

materials and a lot of carbon in all the right places 

allow an unbelievably low weight at a high strength. 

This strength is needed especially during contest 

launches and landings. What if, however, we leave 

contest launches and landings be and only focus on 

thermal and fast gliding tasks? 

To learn and practice how to thermal efficiently, one 

does not necessarily need an expensive contest 

model. We need a light plane with circles well and 

whose flaps allow a safe descent from altitude. It 

should have an airfoil which has low drag at low wing 

loadings, and the “Epsilon’s” MH-32 fulfills this requirement. 

So its important to keep the model light, 

else other airfoils would be more suitable. If, instead of 

hand tow or winch launch, we use an electric motor to 

get the plane to altitude, we also do not need the extremely 

stiff airframe of all-molded carbon models. But 

the model does have to be strong enough to hold up in 

fast descents. It should also be strong enough for simple 

aerobatics. 

The “Epsilon” arrived with all parts cleanly and individually 

packed in plastic. The quality looked good. 

The instructions were excellent with just the right 

amount of information. The parts weighed in as follows: 

right wing inner panel: 316 g 

right wing outer panel: 152 g 

left wing inner panel: 296 g 

left wing outer panel: 150 g 

fuselage with motor: 678 g 

steel joiner 12 mm: 432 g 

horizontal stab: 71 g 

canopy: 34 g 

winglets: 34 g 

accessories: 204 g 

controller: 62 g 

total weight all parts: 2.429 g 

Adding the radio gear and battery yields an all-up 

weight of 2,984 grams. The fiberglass fuselage was 


- 50 - 



quite light, but had a rather wide seam line. A 

brushless outrunner motor came mounted to a 

cleanly installed motor mount. The bell crank for the 

stab was factory installed as well. All wood parts, 

such as servo frames and tray, were precisely laser 

cut. The small parts set was complete as well. The 

stainless steel wing joiner weighed 432 grams. 

Thus the weight can be lowered by about 300g by 

replacing the steel with a matching carbon joiner. 

With the steel joiner, the flying weight still stayed 

under 3 kg. 

All control horns were made from fiberglass and 

came pre-drilled for the linkages. As nice as that is, 

there is a small problem: when inserting the Z-bent 

linkages, the horns split open because not enough 

material was left around the holes. Enlarging the 

holes would have resulted in too much slop at the 

horn. So I dug up some M3 clevises whose pin 

perfectly matched the pre-drilled holes. These I 

soldered to the wire, and I used the included M2 

clevises at the servo end. 

The 4-piece wing came covered in multi-color “Oracover.” 

The workmanship was good and free of 

wrinkles. Wrinkles did form after the first flight, but 

they could be ironed out easily. Flaps and ailerons 

were hinged with “Oracover” also. Here work had to 

be done, because the covering had been shrunk 

too much so that ailerons would hardly move down, 

and the flaps could not quite be brought to neutral. 

There was nothing to do but cut off the control surfaces 

and re-hinge them with tape. 

The alignment pins had to be glued into the predrilled 

holes in the root ribs. The holes had to be 

adjusted a little bit, else the pins would not fit in the 

holes drilled in the fuselage. The root ribs also were 

pre-drilled for the screw hooks, which, together with 

a spring, secure the wings to the fuselage. It takes 

a little bit of fiddling, but it works well. You could 

also secure the wings just with tape. The wholes in 

the fuselage had to be enlarged slightly for the 

screw hooks to fit through. All in all, this is a simple 

solution which needs to fit a little better out of the 

box. 

As mentioned, the wing came in four pieces, and 

while one could leave the wing this way, the instructions 

suggested to permanently join the inner and 

outer panels. I installed four Dymond “D-60S” ser- 

September/October

vos in the wing. They have sufficient torque and are 

lighter than the suggested “D-250X” metal-geared 

ones. I simply glued in the servos and closed the wells 

with the included servo covers. Pull strings were installed, 

which made threading the wiring quick and 

easy. The wings are hooked up to the fuselage with 

Multiplex plugs, which are glued into the root ribs. The 

routed out openings for these fit perfectly. 

I hinged the rudder with CA hinges, and used the fiberglass 

control horn. The music wire for the rudder 

was a little thinner than that for the flap and aileron 

linkages, so installing the Z-bend did not split the rudder 

horn. The linkages worked very well with minimal 

lengthwise slop. The full-flying stab gets mounted by 

first installing the carbon rods and sliding on the stab 

halves. The instructions suggested to secure the stab 

with small grub screws, but the stab was tight and secure 

enough that these were not needed. 

All that remained was epoxying in the servo tray and 

install hook and loop fasteners for the receiver and the 

battery. I used a “Dymond” controller, which fit under 

the servo tray, leaving plenty of space above. 

Although not mentioned in the instructions, I decided to 

add intake and exhaust vents to the fuselage. Included 

was a high-quality turbo spinner, which fit perfectly. It 

differs from others in that it uses a simple pin and a 

circlip to hold on the propeller blades. This does not 

allow adjusting the sideways play of the blades, but it 

worked perfectly in flight. Also nice is the offset yoke, 

which allows the blades to fold flat against the fuselage. 

The plane came with the motor installed. The brochure 

says it’s a “Himax,” probably a “Himax C 3522-0700.” 

Anyway, it works well. Climb rate is about 6 meters per 

second, and 270 meters of altitude are reached in just 

under a minute. From that altitude, you can thermalsoar 

for hours. 

This drive train is perfect for the “Epsilon.” As measured 

with the included 14x8 propeller, static current 

draw is 39 Amperes, decreasing to 35 Amps in flight. 

Data 

“Epsilon” by Staufenbiel 

Electric-Powered F3J Model 



Flying Weight: 2.984 g 

Airfoil: MH-32 


- 51 - 


The motor stays quite cool. I used Hacker “Flightpower 

EVO 30/60C” 3200 mAh batteries which 

weighed about 270 to 280g. I needed an additional 

100 g of nose weight to get the CG to 100 mm. 

Later, I removed 25 g of this nose weight. 

Almost only good things can be said about the flying 

characteristics. Maiden flight happened in difficult 

conditions on the slope with much wind and 

turbulence. But the “Epsilon” was stable and easy 

to fly. It indicates thermals readily by clearly lifting a 

wing tip, and the polyhedral wing makes centering 

the thermal easy. But what about glide performance? 

Horizontal cruise is not very fast. Here the 

plane has clear limits, which partly is due to the 

airfoil. Still, the plane can range out in search of 

thermals. It’s also no problem to spiral down and let 

the plane whistle a bit. But the “Epsilon” does not 

like terminal dives, because the outer panels can 

enter a high-frequency flutter. Gladly, this is ended 

easily by gently pulling out of the dive. Well, the 

“Epsilon” is designed for thermaling, so this difference 

to all-molded carbon birds is not surprising. It 

means that descending from high altitude or getting 

out of barn-door thermals will have to be done using 

the flaps to slow down. Apropos flaps, I was able to 

get 80-degrees of flap deflection, which makes the 

“Epsilon” come down like a parachute. With these 

flaps, the plane can always descent safely and land 

just about anywhere. 

All in all, the “Epsilon” is a great concept, which 

once again proves the Pareto Principle: If you’re 

happy with 80% of optimum performance, you pay 

only 20% of the price. Getting the last 20% to 100% 

optimum, will cost another four times more. This 

sort of fits a comparison of the “Epsilon” with the 

top-end F3J competition gliders. General performance, 

robustness, and quality, however, are not 

compromised by the low price, which can be reason 

enough to chose the “Epsilon” as a F3J training 

unit. 

Volker Kaul 

Price: 289,- Euro (electro or glider), 339,- Euro (with motor, controller, and propeller); Available at Staufenbiel, 

Germany, Tel. +49/40/30061950, www.modellhobby.de. 

September/October


Page 88 

- Can 3.5-meter models be easy to handle on the ground? They can! The “Epsilon” shows how. 

- Easy to grab, easier to launch, and easiest to fly... 

Page 89 

- The ”Epsilon” arrives neatly packed and nicely equipped. 

- Wing planform is very modern. 


- 52 - 


Page 90 

- The horizontal stab also has a modern shape. 

- The pretty and possibly effective Winglets are fastened with epoxy. 

- The fuselage offers plenty of room for larger battery packs. 

- The “Epsilon” also soars well. 

- The performance chart confirms the good climb rate. Climb rate is 6 meters per second, and a 270-meter climb 

takes just under a minute. 

September/October

A Perfect Inaugural Event 


- 53 - 



The first DMFV German Championship for Semi-Scale Motor Gliders 

Note: DMFV = Deutscher Modellflieger Verband = 

German Model-Flyer Association 

The FMC Kinzigtal club hosted this event in early July. 

The championship was the idea of DMFV official Walter 

Peter who wanted to offer a contest in which traditional 

motor gliders could compete on an equal footing 

with modern, powered high-performance gliders. This 

idea made sense, and it was necessary on one hand 

to attract a sufficient number of contestants, while on 

the other it recognized the fact that in recent years 

gliders with self-launch systems (SLS) have increased 

and matured. Indeed all SLS models present at this 

event proved their reliability, as did the traditional motor 

gliders with electric or internal combustion propulsion. 

Well-known manufactures of SLS systems and 

accessories were present to show their products in an 

area set aside especially for them. This way, visitors 

could see the systems up close and engage their developers 

in techno-babble. For example, Dirk Merbold 

demonstrated his control unit for SLS, which features 

many interesting functions (www.merboldelectronic.de). 

About the contest: Fifteen of the 18 pre-registered 

participants were present at the detailed pilots’ meeting. 

The flying program with its tasks and soaring durations 

was balanced such that all models had equal 

chance of winning the event. The initial fear that traditional 

motor gliders — due to their lower glide performance 

— were disadvantaged compared to the modern 

ones, turned out to be unfounded. The winner of the 

event was Walter Keller with a half-scale “RF-4D,” a 

classic motor glider. 


Stand-off static judging required a photo or a scale 

drawing with which the model was compared from 

about 7 meters away. Dimensions were not 

checked. For flight judging, the models had to complete 

six compulsory maneuvers and two free ones, 

all within 15 minutes of working time. Except for 

take-off and landing, all maneuvers had to be flown 

unpowered. Compulsory maneuvers were take-off, 

a procedure turn, a circle, 3-minute duration soaring, 

approach, and landing. Pilots could choose the 

two free maneuvers from a 180-degree turn, a figure-8, 

a triangle, and a rectangle. The judges also 

subjectively evaluated the noise level of the various 

power systems. If you wish to prepare for next 

year’s German Championship, please check and 

down-load the announcement at 

www.motorsegler.dmfv. 

The current German Champion is Walter Keller with 

his “RF-4D” with 5-meter span, powered by an internal 

combustion engine. Second place went to 

Christoph Kurdzel with an 8-meter-span “Duo- 

Discus xT” and Schambeck SLS. Third was Thomas 

Gleißner with a 6.8-meter-span “ASK-21 Mi” 

also with an SLS by Florian Schambeck. 

The DMFV professionally planned and conducted 

the event. The host club supplied many helpers and 

an excellent contest environment, outstanding food 

and drink, and a comfortable camp fire atmosphere 

in the evenings. A big thank you goes to the FMC 

Kinzigtal and the DMFV for setting up and executing 

a great contest. 

Johannes Köllner 

Page 92 

- The winners are (from left) Christoph Kurdzel (2nd), Walter Keller (1st), and Thomas Gleißner (3rd). 

- Group photo with planes at the end of the Championships. 

Page 93 

- Along with the SLS-powered gliders competed several traditional motor gliders, such as this 5.1-meter-span “SF- 

25C.” 

- Powerful take-off of a “Ventus 2c”. 

- The winning model by Walter Keller: “RF-4D,” 5 meter span. 

- Scale take-off of a 2.5-scale “Duo-Discus xT” with Schambeck self-launch system. 

September/October

Made in Germany 

Kontronik Celebrates its 15th Anniversary 

In mid-July, Kontronik celebrated its 15th anniversary 

with factory tours, work shops regarding electricpowered 

flight, and flight demonstrations. The Name 

Kontronik is derived from founder Harald Konrath’s last 

name and the technical term electronic (spelled with k 

in German). Focusing on high-quality controllers and 

brushless motors, Kontronik has become an international 

company. The needs and desires of pilots, builders, 

and general customers always come first, said 

Harald Konrath in his opening statements. Development 

and manufacturing and customer service are 

housed at the company’s facilities in Rottenburg- 

Hailfingen. Everything is made exclusively in Germany. 

The company has about 30 employees and, bucking 

current trends, is ready to grow internationally. The 

factory tours allowed visitors to watch the products 

being made. For example, the various steps of controller 

production: automatic PCB assembly, handsoldering 

of connectors, loading software, adding heat 

shrink, and end control. Same for motors: the machine 

shop, tool making, winding, parts assembly, and final 

checks. The service center also was open to visitors, 

and the whole tour offered unforgettable insight into 

the company. 

This is how it all started: Kontronik was founded at a 

time when the internet was not yet common place, and 

surface-mount devices (SMD) had yet to revolutionize 

the manufacturing of electronics. Harald Konrath, himself 

an active RC pilot, had been building controllers 

for his own use since he was in school. By 1993, others 

wanted to buy his products, and the first ones were 

sold under the name KO-Elektronik. When it was clear 

that electric-powered flight was going to grow, Kontronik 

GmbH was formed in 1994. The first catalog and 

magazine ads appeared in May of that year. Market 

acceptance allowed Harald to quit his job at Daimler. 

Paticipation at hobby fairs followed, and the first controller 

for brushless motors was introduced. Missing 

was a suitable motor, because despite manufacturer’s 

announcements, none were ready for the market. So, 

Kontronik started making its own motors and introduced 

the “KBM” series of brushless motors in April of 



- 54 - 



1996. Contest pilots were sponsored, and national 

and international successes were good advertising 

and made the products known world-wide. After 

operating out of an apartment, the company moved 

to its current facilities in Hailfingen in 1997. Michael 

“Mike” Franz, a permanent fixture at Kontronik, built 

the first Kontronik website that same year. The first 

booth at the toy fair in Nuremberg showed the international 

orientation of the company. Then came 

sensorless commutation of brushless motors, but 

the success of these controllers was mixed at first: 

The year 2000 was plagued by parts shortages as 

cell phone manufacturers gobbled them up. Products 

like the “Beat” series of controllers could not be 

delivered. It took two years for the controller market 

to recover from the cell phone boom, and the 

“Smile” controllers and “Fun” motors were introduced. 

In 2004, many new products hit the market: 

“Jazz,” Konion,” and “Dancer” were well received, 

and outrunner motors, named “Kora,” were manufactured. 

In May of 2005, the facilities were 

enlarged significantly. LiPo batteries were coming 

on strong and pilots expected more from electric 

power. Kontronik answered with its “Power-Jazz” 

products among others. To round things out, the 

“Mini-Pix” series satisfied the booming indoor-flying 

trend. In 2008, the “Kira” motor series with built-in 

cooling for sustained runs replaced the “Fun” series, 

and the ”Jive” controllers caused quite a stir. 

Kontronik again turned toward the contest scene, 

and the “Pyro” series is the first cornerstone of this 

effort. Well equipped for further innovation, the development 

department hired three more engineers. 

The open house in July sent the message that Kontronik 

revolutionizes drive technology for electric 

flight. Certainly, new and innovative products are 

just around the corner — and as always “Made in 

Germany by Kontronik.” 

Thomas Navrath 

- The controllers are assembled automatically. 

- Careful manual craftsmanship is important at Kontronik. 

- Kontronik needs a well-equipped machine shop. 

- Founder Harald Konrath makes his opening remarks at the anniversary of his company. 

September/October

Grand Finale 

F5B/F5F Eurotour in Austria and Switzerland 

Liezen in Austria was the August stop for the Eurotour 

with excellent summer weather and just as outstanding 

organization and contest direction. Pilots from five 

countries came to compete before attending the F5B 

European championships in Romania. 

The good weather allowed for hot propulsion settings 

and high numbers of lengths flown, but a few pilots fell 

victim to the energy limiters or the lack of thermal activity 

and had to land prematurely — which means point 

reductions, of course. On Saturday already, Johannes 

Sterzinger of Austria flew three 1000-rounds, and decided 

the contest for himself ahead of Wolf Fickenscher 

(Germany) and Thomas Waeckerlin (Switzerland). 

In F5F, Dr. Martin Hoff got so far ahead in the first 

round, that his lead held up to the end. Despite two 

1000 rounds, Patrick Haeusler (Switzerland) came in 

second followed by Gottfried Schiffer (Austria) and the 

seasoned champ Rudi Freudenthaler (Austria). F5F 

Eurotour leader Thomas Waeckerlin (Switzerland) had 

technical difficulties in one round and sank out in another. 

He ended up 7th, even though he flew 41 

lengths, a top result, in the third round. 

A surprising performance was delivered by F5D world 

champion Daniel Mayr in his first F5B competition. 

Without much practice, he came in 10th with a regular 

kit plane and a modified F5D motor. His F5D-type flying 

style was spectacular with an extremely low last 

base-B turn. 

Well-known for its pylon events, the WSV Liezen club 

hosted its first F5B Eurotour perfectly. A big “Thank 

You!” to all organizers and helpers. 



- 55 - 



A few weeks later, the F5B/F5F Eurotour held its 

final contest of the season on Buttikon, Switzerland. 

The winners had not yet been decided, because 

only a few points separated first and second places 

in either class. After some exciting rounds at this 

nice field in Buttikon, local pilot Thomas Waeckerlin 

won both classes before his club college Patrick 

Haeusler, who deservedly earned the title “Rookie 

of the Year.” Patrick has been active in the DS (dynamic 

soaring) scene, and now he made himself 

known with top placements in F5B and F5F. 

Overall four-time winner of this year’s F5B Eurotour 

was Wolf Fickenscher (Germany), followed by 

Remo Frattini (Italy) and Johannes Starzinger (Austria). 

Fourth and fifth were Guntmar Rüb and Heiko 

Greiner (both Germany). 

F5F — the old 10-cell class, now 4s LiPo — was 

won by Thomas Waeckerlin (Switzerland) with Rudi 

Freudenthaler coming in second, just like they did in 

2008. Bernd Bossmann (Germany) came in third 

with his flying wing before Dr. Martin Hoff and 

Gottfried Schiffer (both Austria). 

The contest went smoothly under Emil Giezendanner’s 

(Switzerland) direction and the hospitable 

atmosphere at the field. That the current rules (Li- 

Pos and limiters) are popular can be seen by the 

increase in participants this year. There were also 

several new pilots and juniors. If one is willing to 

practice and prepare, it’s now possible to successfully 

compete with commercially available planes 

and equipment. 

All-in-all, these are great conditions for an interesting 

and exciting world-championship series in 2010. 

Dr. Martin Hoff 

- The F5F Eurotour was won by Thomas Waeckerlin (Switzerland) with Rudi Freudenthaler (Austria) and Bernd 

Bossmann (Germany) coming in second and third. 

- Liezen F5B: Johannes Starzinger (Austria), first; Wolf Fickenscher (Germany), second; Thomas Waeckerlin 

(Switzerland), third. 

- Liezen F5F: Dr. Martin Hoff (Austria), first; Patrick Haeusler (Switzerland), second; Gottfried Schiffer (Austria), 

third. 

- Buttikon F5F (from left): Patrick Haeusler (2), Thomas Waeckerlin (1), and Rudolf Freudenthaler (3). 

- Buttikon F5B (from left): Patrick Haeusler (2), Thomas Waeckerlin (1), and Remo Frattini (3). 

September/October


The next issue comes out 

on 22 December. 

Follow up online: 

- 56 - 


www.AUFWIND‐magazine.net 

September/October

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