Oct - Rcsoaring.com

SoaringDigestRadi C ntr lledOctober 2008 Vol. 25, No. 10

CONTENTSOctober 2008Vol. 25, No. 103 RC Soaring Digest Editorial4 The F3J ExperienceSeattle 2006, Chicago 2007, Adaparazi 2008The road to the World Championships.By Sherman Knight42 Wings With a TwistPitcherons and wingerons detailed by Steve McKinlay.49 Miles and Storks Mean Smiles and TurkeyA new two meter from Murat Esibatir and Philip Kolb, acontest, and an avian phenomenon. By Sydney Lenssen54 What a Landing!By Daniel Bizzera56 Klingberg Wing 100, RevisitedRol Klingberg's large ’wing, built by Tom Hoopes, isfinally made airborne by Tom Nagel.Front cover: Jack Cooper and Joe Chovan fly in closeformation with a pair of Leading Edge Gliders Lockheed P-80Shooting Star slope jets. Photographed at WilsonLake Kansas by Dave Garwood using a Canon EOS 40D and70-200 f/4 lens. ISO 800, 1/750 sec., f8.0, 160mmThe Ferengi Rules of Soaring 65Ira Steven Behr, the Executive Producer of Deep SpaceNine, wrote the Ferengi Rules of Acquisition. Rumor hasit that Ira was also a sailplane pilot... By Peter CarrTinamou 66Curtis Suter's long-term interest in swept back flyingwings leads to a beautiful and good flying RC sailplanenamed after a secretive tailless bird.Campbell 78Greg Potter talks about his bio-retreiver.Back cover & Contents page background:Matt Tillman's Super J-II RES electric sailplane, a planespecifically designed to take advantage of the lack of a zoomon electric climbout. It's powered by an Axi 2212/20 turninga 10x8 prop, with an AUW of ~22 oz, depending on ballast.The pod and boom are from Art Hobby, the fin is that of anAllegro, and the wing and stab are Matt's design. Photo byJulie Tillman at the field of the Patuxent Aeromodelers inHollywood Maryland.Canon PowerShot A630, 1/1250 sec., f3.52 R/C Soaring Digest

R/C Soaring DigestManaging Editors, PublishersContributorsB 2 KuhlmanDaniel BizzeraPeter CarrSherman KnightSydney LenssenSteve McKinlayTom NagelCurtis SuterGreg PotterMatt TillmanPhotographers Dave Garwood Greg BellDave BeardsleyJim CooneyShawn Keller Sherman KnightSydney Lenssen BobMcGowanSteve McKinlay Mark NankivilFrank SlaughterCurtis SuterJulie TillmanJeff VrbaContactrcsdigest@themacisp.netWeb: http://www.rcsoaringdigest.comYahoo! group: RCSoaringDigestAIM screen name: RCSDigestMicrosoft Messenger: rcsdigest————————————————————R/C Soaring Digest (RCSD) is a reader-written monthly publicationfor the R/C sailplane enthusiast and has been published since January1984. It is dedicated to sharing technical and educational information.All material contributed must be exclusive and original and not infringeupon the copyrights of others. It is the policy of RCSD to provide accurateinformation. Please let us know of any error that significantly affects themeaning of a story. Because we encourage new ideas, the content of eacharticle is the opinion of the author and may not necessarily reflect those ofRCSD. We encourage anyone who wishes to obtain additional informationto contact the author.Copyright © 2008 R/C Soaring DigestPublished by B2Streamlines P.O. Box 975, Olalla WA 98359All rights reservedIn the AirThe RCSoaringDigest Yahoo! group celebrated amilestone on August 21, shortly after the Septemberissue was put on-line, when an RCSD reader in Francebecame member number 1500. Membership in thisgroup is, of course, just a fraction of the total RCSDreadership. And yes, readership continues to grow.A recent issue of another popular RC aircraft magazinereviewed the Great Planes ElectriFly L-39 Albatross.This molded foam fun-scale model is rather small(the wingspan is just 25 inches) and is designed forelectric ducted fan. The $99 package includes theHyperFlow ducted fan and an Ammo brushless motor,but that doesn't mean you have to build and fly it withthose components installed. If any RCSD readersare contemplating a conversion of this cool lookingmodel from EDF to PSS, we'd very much appreciate anillustrated article on the process and the result.We're looking for someone to reestablish "The ToolRoom" as at least a somewhat regular column. Dremel'sMulti-Max Oscillating Tool System, scheduled tobe available in October, would make an excellent firstsubject. If reviewing newly introduced and/or lesscommon tools sounds like something you'd like to do, weencourage you to contact us.Time to build another sailplane!October 2008 3

The F3J Experience:Seattle 2006...Chicago 2007...Adaparazi 2008Sherman Knight, duworm@aol.comIn December 2006, Dave Beardsleymentioned to me that the F3J WorldChampionships in 2008 would bein Turkey and that we should see ifwe could qualify our kids. Soundedinteresting, especially the Turkey aspectof it. “I’m in, sounds cool.” What I didn’trealize at the time was I was about toexperience the most difficult thing I havedone since I started flying — handinga perfectly good, brand spankin’ newCarbon/Kevlar sailplane to a 13 year oldwith a smile on my face while saying“Have fun out there,” and walking away.And not once, but with three differentplanes!At the time, I only knew one thing aboutF3J. A couple of guys with track shoestowed the plane on launch. My learningcurve was going to be steep, but whatthe heck, we were shooting for the WorldChampionships!F3J has lots of rules, lots and lots ofrules. Towline length limits, tow bridalconstruction restrictions, safety zoneflight limits, parachute size restrictions,launch windows and a bunch of others.Even the line used for launching wasdifferent. In Thermal Duration, slap onsome #300 line and go. In F3J the towlineis monofilament. Sounds easy, but youreally wanted a certain brand of mono.Something called “Speedline” was themono of choice. A quick Google searchand NOTHING, zip, nada. It took monthsto track this stuff down. And you needit in at least three different diameters.The more stretch (lighter line) the better.Unfortunately, as headwinds increasedon launch, the lighter line would break,requiring a heaver line. Balancing theweight of the aircraft, the strength of4 R/C Soaring Digest

the towmen and the strength of theheadwind was required to select thecorrect size of the monofilament tow line.Too heavy and the launch suffered. Toolight and the line broke. And you did notwant to break a line. Break a line onceand that flight just became your throwoutround. Break a line a second timeand you did not make the fly-offs. Inother words, no podium for you.Each competitor is allowed only threeaircraft for the competition. At the WorldChampionship level this means threeprimary aircraft. A primary with a coupleof old planes that are still in pretty goodshape does not cut it. Unfortunately,you really need more like four or five.(The reasons will become clear laterin this article.) You are not allowed toreplace any part of the aircraft like a newfuselage or a new wing tip panel. But youare allowed to repair them all you want.Bring your repair kit, because you WILLbe doing repair work. What is it aboutF3J that damages more aircraft than aThermal Duration contest?F3J does not allow landing skegs ofany kind. Hard dork landings aren’t justtypical, they are required. In addition,there are lots of planes in close proximityto each other. Because scoring for eachround is Man-on-Man, up to 16 aircraftlaunch at the same time from lanes only35 feet apart. That also means 16 aircraftsetting up for approach at the sametime. Because of the follow-the-leadermentality many competition pilots have,that also means up to 16 planes in thesame thermal at one time. You guessedit, F3J is a contact sport!Daryl Perkins reduced the entire strategyof F3J to one sentence. “F3J is all aboutthe first three seconds and the lastthree seconds.” Huhhh? Like ThermalDuration, the clock starts when theplane comes off tow and starts when theplane touches a ground based object.Unlike Thermal Duration you mustlaunch and land in a ten minute window.In other words, it is impossible to geta ten minute flight within a ten minutewindow. Time on tow and landing earlyis subtracted from the ten minutes. Tomake the fly-offs, you get one throw-out,you make your time in all the remainingrounds, you launch in less than threeseconds and you land inside the lastthree seconds. This strategy will work atthe local contest level, but it will not beenough to make the fly-offs at the WorldChampionship levels.Man-on-Man scoring takes the bestscore in the round and gives that person1000 points. All the other pilots’ scoresare normalized against that 1000 points.So, if all the pilots in the same roundland early, the best score still receives1000 points. Under this system, no pilotis penalized for being unlucky enough tofly a round in bad air when the roundsbefore and after flew in great air.F3J rounds take place in a ten minutewindow. If you land early, that may havejust become your throw-out. The aircraftmay not leave the thrower’s hand until thewindow opens and the plane must landbefore the ten minute window closes.If you launch early, you must re-launchin that window. Oops, that just becameyour throw-out. If you land after thewindow closes, a severe point penalty isassessed. Darn, another throw-out!There are other “throw-out” causingevents. Land more than 75 feet from thelanding zone, another throw-out. Fly overa safety zone under three meters, “OopsI did it again.“Unfortunately, you only get one throw-outleading up to the fly-offs. In the 15 minutewindow fly-offs, if six rounds are flown,there is another throw-out.The Selection TrialsThe road to the World Championshipsgoes through the selection trials for eachcountry. For Team USA, the selectiontrial were sponsored by SOAR, the localSoaring club near Chicago in Septemberof 2007. By March of 2007, there werethree Dads and their sons going tothe trials from the Seattle area. DaveBeardsley and his son Brendon, myselfand my son Michael, and Jim Laurel andhis son Connor.October 2008 5

Jim Laurel found a bunch of thehardware we needed from Skip Miller.Grinders, spools, tow pulleys, F3J chutesand a bunch of general knowledge.Thanks Skip. We traveled to a TD contestjust outside of Vancouver BC Canadaand got a bunch of hands-on help fromArend Borst, past F3J World Champion.Thanks Arend. By the beginning ofSummer 2007, we had all the equipmentand some great advice, but we still didnot have any contest experience.Then we met “The Damn Canadians,”actually a group of Americans thathave been going to the selection trialsfor years and just like the name. AmyPool, Kelly Johnson, Bill Hanson, DavePortwood and Jim Frahm providedus with a lot of help and asked us tojoin their team. This provided us withtowmen, support staff, throwers, anda horse trailer that drove from Portlandto Chicago and took all our planes andequipment. I cannot begin to tell you howmuch help it was to have experiencedpeople around to guide us. Thankseveryone.Nonetheless, the lack of actual contestexperience still bit us in the butt. Whenwe arrived at the selection trials in earlySeptember, 2007, during practice, one ofMichael Knight’s three planes suddenlyhad a case of confused electrons andan intermittent fault forced us to retirethe aircraft. The decision to retire theaircraft rather than try to repair it wouldlater come back to haunt us. Then in thevery first round, lack of familiarity withthe rules struck. Michael thought thatflying over a safety zone would penalizehis flight, so he elected to fly aroundthe safety zone. (The actual rule onlypenalizes a pilot for flying under threemeters over a safety zone and Michaelwas way above three meters). Flyingaround forced a landing 78 feet from thelanding box, just three feet outside of the75 foot limit. The result was a zero flight.Michael’s very first flight was his throwout.Yikes!By the second to the last flight, Michaelclimbed into second place, just behindAJ McGowan, with Brendon Beardsleyin third. BAM! Michael mid-aired withNick Tasco. After the planes separated,Michael started flying the wrong airplane!The uncontrolled descent of his primaryplane (a really nice red and white Supra)resulted in a plane that was no longersafe to fly, no matter how much you triedto repair it.Under the rules, the mid-air gave Michaeland Nick the right to re-fly the round.Unfortunately, our earlier decision toretire rather than repair one of the backupaircraft left Michael with a singlebackup plane that was not well suitedfor the conditions in Chicago. Brendonmoved up to second, Michael fell backto fourth, and Jeffery Walter made theJunior team finishing in third.So Team USA for 2008 consisted ofDaryl Perkins, Ben Clerx, and RichBurnoski, and Skip Miller as alternate forthe Seniors. The Junior team consistedof AJ McGowan, Brendon Beardsley,and Jeffery Walter, and Michael Knightas alternate. In addition, because he wonthe junior event two years earlier, CodyRemington received an automatic bid tothe World Championships.Right after the Selection Trials, the nextorder of business was to select TeamManagers for both the Senior and Juniorcompetitors. Jim Monaco was chosenfor the Seniors and Mike Lee was chosenfor the Juniors. It is impossible to explainhow much work these two guys put into make to make the upcoming WorldChampionships happen. We cannotthank them enough.Opposite page:Senior Team, from left - Rich Burnoski,Ben Clerx, Daryl PerkinsCody Remington, Junior Champion,WC 2006, competing as Senior in 2008Junior Team, from left: AJ McGowan,Jeff Walter, Brendon Beardsley6 R/C Soaring Digest

October 2008 7

Well, Michael did not make the team, butthen we found out about the Spor YapiCup. It is a two day event right beforethe World Championships. We could stilltravel to Turkey and fly against the bestfrom around the world. Because F3Jcompetition is so hard to find in the USA,we decided a little practice in Turkeywould be fun.TurkeyThe World Championships are held everyother year and hosted by a differentcounty each time. This year the hostcountry was Turkey. Jim Laurel, the worldtraveler that he is, kept telling me howcool Turkey was to visit. I did not knowwhat to expect, but I had seen the movie“Midnight Express” when I was in collegeand it scared the crap out of me. I knewthat Syria and Iraq border Turkey to thesouth and the current news was tellingme that both those countries might notbe a good place for Americans to visit.Istanbul, the largest city in Turkey, is the“City of Intrigue” found in every other spynovel I have read and in several JamesBond movies. In addition, my Hollywoodeducation seemed to tell me that I shouldexpect sand dunes, camel caravans,men wearing turbans and womenwearing burkas.Jim Laurel was right in a big way. Turkeywas a very cool place to visit and myHollywood education was way off. Not asingle sand dune or camel, and no menwearing turbans, and only a few womenin burkas.What we did see was HISTORYcombined with a modern society.Buildings and structures, some morethan 2000 years old, across the streetfrom a modern light rail mass transportsystem that went by whisper quiet. Youcould easily spend several weeks visitingreal history. I can remember thinking inmy architectural history college class,“What is so special about a bunch ofold buildings?” After visiting Turkey I canfinally appreciate the truly impressivenature of the ancient architecture.Turkey’s freeway system is comparableto anything you would see in the States.McDonald’s, Burger King and Starbucks,just like home. Although I could not readthe menu and the person behind thecounter could not speak English, I couldsee the images on the overhead menu,hold up the right number of fingers andsay, “Number seven.” Some things onthis planet are universal.The event was held just outside of thecity of Adaparazi, a city of about 400,000and a three hour car ride to the east ofIstanbul. On the drive there from Istanbul,we passed highly industrializedareas, huge warehouses, tower cranesand apartments — lots and lots of apartments.It was a dry, dusty environment.Adaparazi, on the other hand, is in alarge valley surrounded by green. It isheavily irrigated. The city itself is oldwith very few buildings higher than fourstories. Nearly 10,000 died there in anearthquake over ten years ago. Some ofthe earthquake damage is still apparent.In stark contrast, scattered throughoutthe city are modern shopping malls. Walkin the door and you can buy some jeansfrom the GAP.The next morning, a tour bus organizedby the event coordinators shuttled us outto the flying site. A quick jaunt acrosstown in the tour bus shows that Drivers’Education in the States is much differentthan Turkey. The bus, alongside othercars and trucks, would whip throughroundabouts, traffic lights were ignoredby everyone, horn beeping and fistshaking were as much a part of drivingas stepping on the accelerator. Carsand trucks flying in formation so close itwould impress the Blue Angels.We finally made it to the freeway and itwas just as interesting. Hmmmmm, theregoes a car traveling the wrong way downthe shoulder. Suddenly the bus pulls aU-turn in the middle of the freeway and,a few hundred feet later, quickly pulls offonto a narrow dirt road. The bus is flyingdown the dirt road next to a river withbanks so steep you wonder what keepsthe road from sliding into the river.Another sudden turn through an openingin a big dirt berm and we saw it. Nirvana— paradise for a sailplane pilot. A HUGE8 R/C Soaring Digest

Tents are a poor description of the shelters provided by the event organizers.green, well-cut grass field. The field held16 launch lanes and 16 landing zoneswith lots of room left over. Anchor pointsfor launching equipment, along withsafety zones and large digital clocks,were already set up to allow launchingand landing in three different directions.Just a few moments later we saw thenext indication that this competitionwas going to be the best organized andpresented event ever. Team vans. TeamIstanbul had not just one, but three teamvans, painted from bumper to bumperwith sailplane and Istanbul graphics.Right behind the team vans were raisedspectator bleachers and a celebrationpodium. And just beyond the podiumwere the tents.Tents are a poor description ofthe shelters provided by the eventorganizers. Think more like metalbuildings that used plastic coveredOctober 2008 9

The scoring tent. The Istanbul Soaring Club vans.canvas for the roof and walls. Separatesections for each country. A separatetent for the official scoring judges, theCD and his crew, and a separate tent forthe transmitter impound. In addition, twocovered areas for competitors to hangout and watch the scoring in real time.Yeah, that’s right, real time scoring.Hosting an F3J contest is a manpowerintensive endeavor. Each lane requiredthe host to provide an official timer. Theofficial timer would start his watch whenyou came off tow, and stop the watchwhen you landed. He was also responsiblefor verifying your landing score. Hewould then enter the two scores into awireless PDA. Once the information wasentered, and you verified that it was correct,you would give him your private PINnumber. He would enter the PIN numberand the wireless PDA would instantlyupgrade the scoring computer. As soonas all scores for the round were entered,the scores would print out on big plasmascreen TV’s in the pilot hang-out areas.In addition, if you had a wireless laptop,you could log onto the wireless networkand see the scores update in real timefrom your own tent. Absolutely incredible.The Spor Yapi CupBefore the World Championships, youget to warm up in a F3J mini-event calledthe Spor Yapi Cup. Just four rounds(because there are less than six rounds,no throw-outs) and the best 15 pilotsthen fly in a two round fly-off. The USAwas represented by seven seniors andfour juniors. From countries around theworld, 153 pilots participated.Prior to the cup, I had no actual F3Jcontest experience. Although I had beento F3J events, it was always in support10 R/C Soaring Digest

of the juniors from Seattle so I did notcompete.At the Cup my flight times were in the9:54 - 9:55 range and I was making my100 point landings. I was feeling prettygood until after the second round when Ichecked the posted scores.I was flying 98.99 percent of perfectand was in 55th place! You have got tobe kidding! Someone patted me on theshoulder and said, “Welcome to the bigleagues.”I was calling for Bob McGowan duringthe Spor Yapi Cup and he educatedme on what it takes to win. He reallywanted a 1000 point round. As we arestanding on the flight line waiting for thewindow to open, we both spotted somehand-launch sign on the deck and itdid not appear that anyone else saw it.Bob pulled up elevator as soon as theplane left the thrower’s hand and wasoff tow in less than a second. He loopedinverted and rolled out, bee-lining for thehand-launch sign. Bob hooked, madehis time and landed with a 9:58:55 and a100 landing. He got the 1000 points thatround.The Cup also gives you the chance toget used to the local conditions. Everymorning, the air was still with very littlethermal activity. As the day went on,the wind would build to a steady 15 to22 knots. Most of us are used to gustywinds, but the steadiness of the windmade it deceptive. It just did not feel thatwindy.The wind was going to be a problem. Welost planes downwind and we blew upplanes on launch.We also had some throwers that werevery impressive. Cody Remington andBob McGowan could load up the linewith the best.But what we had that no one else hadwas monsters for towmen. These guyscould pull. Phil Barnes and FrankieBurnoski towed for the Seniors and DaveKalamen (Brendon’s stepfather) and KellyJohnson towed for the Juniors. Towmen,especially towmen of this caliber, are theunsung heroes of any F3J team. Withoutthese guys nothing happens. When yourOctober 2008 11

At the end of Round 2 I was flying 98.99 percent of perfect and was in 55th place! Youhave got to be kidding! Someone patted me on the shoulder and said, “Welcome tothe big leagues.”team’s towmen are as good as theseguys, magic happens. An F3J tow isquite different from a TD winch tow. Thegoal in F3J is to stay on tow for as littletime as possible. The monofilamentline can be stretched, a lot. Before thelaunch, it is pre-stretched. It appears thatmuch, if not most of the initial part, of thelaunch is the mono trying to un-stretchitself. Then a very, very quick dip at abouttwo seconds to super accelerate theplane before the line returns to normallength and then hard up to vertical. Mostthermal duration pilots stop pulsing thewinch right before the ping. In F3J, thetowmen are pulling hard right through theping. In my opinion, trophies should alsobe awarded to the towmen.We put a stop watch on Daryl’s plane onlaunch. Daryl was off tow in a little overtwo seconds and coasted a hundredfeet higher than other teams planesthat were on tow for over four seconds.Unbelievable!Dave Kalamen and Kelly Johnson alsotowed for Team New Zealand. They notonly blew up a New Zealand carbon PikePerfect on tow (broken fuselage), theytowed New Zealand to a third place Teamfinish in the World Championships.During our practice day and the first fourrounds of the Cup we damaged a littlehardware.First day of practice, AJ was standingnext to a launch line that ripped hisplane out of his hands by a surpriseunannounced launch and it fell on a wingtip. A little CA, a little spackle, and almostas good as new.Daryl damaged his first model inpractice. The stab failed under enormousline tension in very extreme conditions.Daryl pointed out to me later that thistype of problem happens at a WorldChampionship on the practice days asmodels are being optimized, tow systemsoptimized, the entire team is finallytogether and working in harmony, and12 R/C Soaring Digest

adrenaline is up in preparation. In short,with the large geographical challengesthe US presents, there is no way toget everyone together to practice a fulltension launch until you get everyonetogether at the World Championships.The plane flew again with a borrowedstab.Also during practice, the center panelof Brendon’s “lite” aircraft fluttered onlaunch. We repaired the skins and built abox around the servo connecting the topand bottom skins in an effort to eliminatethe problem. It worked. I think that Daryllater built a similar “field upgrade” intohis own planes. No flutter the rest of thecontest.AJ McGowan had an off field landing inthe Cup when the plane just would notpenetrate in the high winds late in theafternoon. Lucky for him, no damage.Rich Burnoski had a great looking Suprauntil it hit the thrower’s hand on launch.The stab was toast along with the centersection. Rich located a new “lite” centersection and a new stabilizer. The Teamjumped in and repaired the plane inabout six and a half hours. Unfortunately,on its first test flight, the “lite” centersection failed. The wing, fin/rudder andfuselage were destroyed. The brokenfuse was repaired, and the fin/rudderreassembled and reattached. A wing andstabilizer were borrowed from Joe Wurts.Over the next several days the plane wasrepaired and reassembled.With up to 16 planes on launch at onetime, near misses were not just common,they were the rule. As the secondsbefore launch ticked down, we began toresemble rabid NASCAR fans looking forMike Lee, highest scoring Spor Yapi Cup pilot with a NAN Modelsmodel, won this brand new NAN Models Xplorer for his effort.the inevitable pileup in turn one of thefirst lap. All eyes were on the flight line foreach launch. You could hear collectivegasps from the crowd when near missesoccurred. When there was contact, it wasspectacular.October 2008 13

Brendon Beardsley feeds AJ McGowan a fish of unknown nomenclature during dinneron the Black Sea. Sometimes not knowing what you’ve ordered has its positive side.After one such collision, one planemanaged to fly under control (well, sortof under control) with the back half ofthe fuselage from the other plane firmlyimbedded in its leading edge. Rudder,stabilizer, fuselage and dangling controlrod sheaths all hanging from the wing ofthe wrong plane!Team USA only had one launch wheretwo planes shared the same airspace atthe same time. Again, the towmen andthrowers made a huge difference. Thebest way to avoid the NASCAR pileup inturn one is to be the first car into the turn.That way, the crash is behind you. TeamUSA did something similar on launch.From a distance, you could clearly seethat the extreme loads on the tow linethat Team USA was using acceleratedtheir planes to the front and any otherplanes crossing their launch lane usuallycrossed behind them.After four rounds, the USA placeda bunch of pilots in the finals. DarylPerkins, Rich Burnoski, Ben Clerx andMike Lee all made the final 15.At the conclusion of the three roundfinals (remember, all preliminary scoresare thrown out), Daryl was in secondwith a silver medal, Rich Burnoski wasin fourth, Mike Lee in seventh and BenClerx in eighth.Mike Lee was the BIG winner here.Mike was the highest scoring pilotflying a NAN Models plane. As a result,NAN Models presented him with a brandspankin’ new Xplorer. It is a gorgeouspiece of work. Painted with a mini-metalflake finish and graphics on the wing tips,it is a very impressive plane.Dinner on the Black SeaAfter the Spor Yapi Cup we had a littlebreather, so most of us got on the bus,and an hour later were on the Black Sea.About half the group went for a swim.Later, we had dinner at a restauranton the water. No one working for therestaurant spoke English, so we have noidea what we ordered, but it was verygood.14 R/C Soaring Digest

The WorldChampionshipsThe Team EventThere were 77 individuals in the WorldChampionships with teams representing25 countries in the Senior event. Inthe Junior event, there were 44 pilots,with teams representing 17 countries.The extreme daily change in weatherconditions continued with no lift andno wind mornings to winds in the earlyafternoon from 15 to 22 knots. Twelve 10minute rounds were scheduled for thepreliminaries and six 15 minute roundsfor the fly-offs, each with a single throwout.Only 11 pilots would make thefly-offs for the seniors and nine for thejuniors. In addition, the number of planesflying at one time was reduced from the16 in the Spor Yapi Cup to just 11 in theWorld Championships.There is both a team event andan individual event in the WorldChampionships. The preliminary roundsdetermine two things. First, it determineswho makes it into the fly-offs to ultimatelydetermine the individual winners. In thefly-offs, your scores are wiped clean andyour scores literally start over. Second,the preliminary rounds also determine theplacing of the team.Although this was a F3J contest (athermal event), a slope fest broke out.The tents paralleled a line of treesdirectly downwind. The wind, blowingat 90 degrees to the tents with the treesbehind provided a little sloping action,directly overhead and well within arock throw. The slope action, althoughtechnically not allowed under the rules,was tolerated for four, five and as long assix minutes. You would be hard pressedto find a single pilot that could claim thathe/she never used the slope lift off thetents.During practice the day before theWorlds, Brendon landed off field with hisEspada RL. Brendon got lucky and couldactually see where the Espada wentdown and walked right to it. The fuselagewas messed up, the tail surfaces weretrashed, linkage was destroyed andOctober 2008 15

US Senior WC F3J Team: Ben Clerx, Frankie Burnoski (towman), Rich Burnoski,Daryl Perkins, Phil Barnes (towman), Jim Monaco Team Manager, Cory Remington.16 R/C Soaring Digest

US Junior WC F3J Team: Dave Kalamen (towman), Brendon Beardsley, AJ McGowan,Mike Lee Team Manager, Jeff Walter, Kelly Johnson (towman)October 2008 17

This page: A small portion of the models at the F3J WorldChampionships. Pike Perfects, Xplorers, and more.Opposite page: Mass launches are the rule, leading toincreased chances of mid-airs. No launching early, launchlate and you minimize your maximum flight time.18 R/C Soaring Digest

October 2008 19

120 R/C Soaring Digest3

2October 2008 214

One of the big screen plasma TVs set up to provide contest inreal time. Very impressive.servo gears were blown. Joe Wurts repaired the fuselage andDave Beardsley glued his fingers together repairing the rudderand linkages. The plane flew later as Brendon’s backup.Many pilots chased the thermal downwind; way, way downwind; “Which plane is mine?” downwind. In Round 1, JefferyWalter went downwind and didn’t make it back. The Britishteam found it five days later in a corn field while they weresearching for one of their own lost planes. Amazingly, there wasno damage.Ben Clerx mid-aired with David Hobby, two time F3J WorldChampion in Round 2. They were both way downwind and fairlylow. The violent collision tore off the aileron wing tip panel fromBen’s Aspire and cracked the tailboom. Ben recovered from theBob McGowan can throw really straight and the towers arereally pulling. The black box on the ground is a speaker soeach pilot could clearly hear the countdown.22 R/C Soaring Digest

spin and managed to fly the plane backto the field! Mike Lee was downwindin the trees looking for someone else’splane when he heard the collision andspotted the falling wing tip panel. Eventhough Mike got a great spot on wherethe wing tip fell, it took eight of us, armspan apart and trying to “swim” throughweeds and corn taller than us before wefound it. Without Mike’s spot, the wing tipwould still be in Turkey.The damaged leading edge was cutaway and a replacement section fromthe leading edge of a Supra was cut tofit and glued in place. Some carbon towimpregnated with epoxy was applied tothe fuselage and the whole area wrappedin thick Mylar. After allowing the epoxyto cure, the next morning the plane wasairworthy.Also in Round 2, a plane on launchtouched the underside of Rich Burnoski’sSupra. The plane next to him sufferedsome wing tip damage and Rich’s planeappeared undamaged.Dave Kalamen and Kelly Johnson, themonster towmen for the USA JuniorTeam were also towing for Team NewZealand. These two managed to blow upa carbon Pike Perfect on Launch. Theplane was repaired with carbon cloth, CAand finishing resin. The plane flew again.Kelly and Dave changed their towingtechnique at the request of DaveBeardsley, John Walter and BobThe Friday before the fly-offs, Mustafa Toc, from Team Turkey, brought inhis helicopter to help search for lost planes. Even eyes-in-the-sky wereunsuccessful, and none of the missing planes were found.McGowan (all Junior team dads) andJoe Wurts at the request of the Kiwis.In higher wind they would let the glidersstop them, but not give ground. Theyalso started briefing pilots before eachflight on what the towers were goingto do for the conditions and directedthe pilots to watch their flex and fly thelaunch, because the towers cannot seewhat is going on.I hope you are beginning to understanda monofilament launch with big towmenand a great launcher in a big headwind isway more powerful than anything you willever see from a Thermal Duration launch.These launches were downright violent!On a Thermal Duration winch, if you overload the winch, the winch just slowsdown. It is impossible for a typical TDwinch to put the forces on a plane thattwo monster towmen can do in windyconditions.Radio issues struck Jeffery Walter inRound 5. Jeffery was using one radio,but like everyone else was taking twoplanes to the launch area. Confusedelectrons made his primary plane unflyable.He switched models in his radioto the backup plane and another caseof confused electrons. Jeff was forcedto retire from the round. Back in the pits,Jeffery successfully bound his planesto his backup radio and finished thecompetition.October 2008 23

Clockwise from upperright:Bob McGowanBarry Kennedy ofKennedy Composites.Barry served as Helper/Assistant, Photographer,etc.Junior AlternateMichael KnightTeam Manager JimMonaco (L) and CodyRemington’s father (R)check out the scores inreal time.24 R/C Soaring Digest

Above and clockwise: Junior Team towmen, Kelly Johnson (L)and Dave Kalamen (R), and Senior towmen Frankie Burnoskiand Phil BarnesOctober 2008 25

Right: What was left ofRich Burnoski’s Supra stabafter its collision with thelauncher’s hand, and theresult of a lot of repair work.Below: Ben Clerx working ona Supra stab, and the resultsof his efforts, a few dayslater, mounted and ready togo.26 R/C Soaring Digest

Clockwise from above:The Supra wing donated by Team Japan, cut up to repairvarious Team USA Supras.Ben Clerx’ Aspire wing following repair after a collision with2006 F3J WC David Hobby’s aircraft.Dave Beardsley repairing the center section of son Brendon’s“lite” aircraft after it fluttered on launch. Notice all of thediagonal repair work. Additionally, all of the servo mounts werereinforced with boxes, strengthening the weak points.Rich Burnoski’s repaired wing tip.October 2008 27

Servicing the radio determined that the confused electronswere in the antenna wire, between the RF output section of theradio and the base of the antenna. We are not sure if it was aloose connection or a broken wire, but the resulting intermittentfault was enough to retire the radio.After the contest was over, we did the math and determinedthat all Jeffery had to score in Round 5 to move the USA JuniorTeam into first place was 549 points.At about this same time, I noticed that many of the pilotschecking their radios into the impound area checked theradio in a radio case. Many of the cases were oversize, whichseemed odd, until I realized that the oversized cases actuallyhad two radios in them. These pilots took two planes and tworadios to the launch area. Live and learn.Remember the contact that Rich suffered on launch inRound 2? Well, he thought the plane was undamaged, but nowthinks it may have caused enough damage that the plane failedin Round 5 in the high winds and launching into lift.Cody Remington landed off field in Round 5. His parents lookedevery day for the next week. Dave Beardsley, myself, andseveral others spent an entire day looking for the plane. It wasnever found.Landing off field at this event not only created an instant throwoutround, but it created a lot of grief for the people looking forthe plane. The mix of trees and corn made finding a plane VERYdifficult and in Cody’s case impossible.The trees are actually a crop. The trees are harvested every sixyears or so and turned into toothpicks. They were about 35 feettall and the canopy created by them was very dense. Mixed inwith the trees were fields of corn that was about a month fromharvest and already a foot taller than me. If the plane camedown in the corn or the weeds surrounding the corn, you had toliterally step on the plane to find it.AJ McGowan wearing his beaver hat. It definitely seemed tohave an intimidating effect on the other competitors.According to the odometer on the bus, the freeway was exactlyone mile downwind from the field. One plane was found justseveral hundred feet from the freeway!Brendon Beardsley had a mid-air with a parachute from thenext lane on launch. That’s right, a mid air with a parachute.During launch, Brendon’s plane jerked and started flyingdifferent. It wasn’t until he landed that we figured out whathappened. The pilot next to him popped off early. Somehow theother pilot’s launch line caught in the gap between the flap andthe aileron and as Brendon launched, the chute pulled throughhis wing, blowing a hole in the center panel, de-laminating theaft portion of the outboard panel, and removing a portion of theaileron. No one actually saw it happen, but the perfect circularindentation from the ring at the top of the chute in the top of28 R/C Soaring Digest

Joe Wurts, Manager for Team New Zealand,helps out with a repair for Team USA.Brendon’s wing was unmistakable. Brendon knew somethingwas wrong with the plane on tow, but he didn’t hit anotherplane. If Brendon had known he flew through someone else’sline, he would have been entitled to a re-flight. But not knowing,and aware that every flight might count, he just re-trimmed andsuccessfully flew it out.The delamination on the outboard panel was repaired, themissing piece of aileron was found and reattached, and a newpiece of wing was used to cover the hole in the center panel.The plane flew again.Daryl did his thing and impressed the crowd in Round 8.Wind is up, line is tensioned to its max, two seconds beforethe window opens the towmen take off, as the window opensthe thrower releases and BAMMMM, the stabilizer decides toremove itself from the plane. Daryl does not flinch. He rolls theaircraft inverted and lands upside down using the flaps like anelevator. No further damage to the plane. Less than 35 secondshave passed.Daryl picks up his backup aircraft, wind is up, line is tensionedto the max, towmen take off, two seconds later the throwerreleases and BAMMMM, the stabilizer tries to remove itself fromthe plane. This time the stabilizer remains attached, just oneside is broken and hanging down at an 80 degree angle. Daryluses all the down trim available and has to hold down stick tokeep the plane flying. Word travels quickly through the crowdand within seconds everyone is watching. The rabid NASCARfan mentally has fully taken over and they can smell a crashcoming. Will he make it?Not only did he make it, but he shot and made a landing, too.Then he fell over mentally exhausted.In Round 10, Cody was on approach, about ten seconds out,when he was mid-aired by a competitor. The collision creasedhis rudder which was easily repaired. Unfortunately, the collisionalso weakened or possibly broke the glue joints in his rudder/elevator box. It went unnoticed in the re-fly and in Round 11. Itis possible that the landing in Round 11 dislodged the box andwent unnoticed until the launch in Round 12. The launch wasvery flat and the plane popped off. Cody, who was in 6th placeat the time and tried hard to make his time from a low launch.Unfortunately, it did not happen and Cody slipped from the flyoffs.After 12 preliminary rounds, the team placing is determined.The seniors finish in 5th place and the juniors finish in 2nd placetaking the Silver medal. Daryl Perkins makes the 11 man fly-offfor the seniors and AJ McGowan and Brendon Beardsley makethe nine man fly-off for the juniors. AJ was flying out of hismind. He finished the preliminary rounds with ten, 1000 pointflights in a 12 round preliminary event. Amazing.October 2008 29

Dave Beardsley photo14530 R/C Soaring Digest

2316October 2008 31

The Multiplex CupThe Multiplex Cup was a chance tolaugh a little. Multiplex provided a bunchof EasyGliders and made it clear thatMultiplex wanted the planes back at theend of the competition. Each team hadone hour to assemble the aircraft. Wefinished and moved to the flightline fora bungee launch contest. Team USAlaunches and the Easy Glider rolls overinto the ground on launch! The teamscrambles, taping the damaged planeback together with blue painters’ tape.They re-launch and the plane prettymuch hit the ground like it did the firsttime. I don’t think I have seen so manypeople laughing this hard all week!David Hobby, two time F3J WorldChampion, won the event.32 R/C Soaring Digest

Above and right: Cody Remington prepares torelaunch the Team USA EasyGlider after putting thedamaged plane back together with blue painters’tape. The relaunched plane pretty much hit theground like it did the first time, breaking off a largepart of the left wing tip and fracturing the aft fuselage.I don’t think I have seen so many people laughing thishard all week! Jeff Walter is on the right.Opposite page: Contestants in the Multiplex Cup.David Hobby, fourth from left, was the winner.October 2008 33

Left: Demonstration of a 4-man tow.Photo by Bob McGowan34 R/C Soaring Digest

Above: One of the many collisions that occurred at the Spor Yapi Cup and the World Championships.This mid-air was captured by Dave Beardsley.October 2008 35

Rich Burnoski and AJ McGowan, with his beaver hat,demonstrate the typical F3J skeg-less landing.36 R/C Soaring Digest

The F3J WorldChampionship Fly-offsThe Individual EventThe fly-offs only determine the individualplacing. The team event is already over.Unfortunately for AJ, all the previousscores are scratched and the pilots startover with a clean slate.The fly-offs consisted of six rounds,but the window was increased from tenminutes to 15 minutes. Even with thelonger windows, so few were flying itseemed like it was over before it started.All of the exciting stuff already happened.There were no more mid-airs or offfieldlandings for Team USA. No planesexploded on launch. The pilots, thethrowers, and the towmen were all actinglike a well oiled machine.Daryl Perkins moved from 11th in thepreliminaries to 6th in the fly-off. If apilot flew five 1000 point rounds, themaximum score would be 5000 points.Daryl was just 8.6 points out of firstplace.Brendon Beardsley finished second injunior class, just 3.8 points out of first.AJ McGowan finished in third place, just5.4 points out of first. The fourth placejunior finisher was 226 points out of first.The US Junior F3J Team with their awards. Mike Lee, Junior Team Manager, on theleft; Brendon Beardsley, AJ McGowan, and Jeffery Walter.October 2008 37

The ASC CupImmediately after the WorldChampionships was the ASC Cup. Thisis a two round contest sponsored bythe gentleman who owns the field. Thewindows were 20 minutes and wereflown in the windy part of the day. Thecontestants were the top three juniorpilots and the top five senior pilots. Thatmeans Team USA had two junior pilotsin the ASC Cup. AJ McGowan, just3.9 points out of first, finished second.Brendon Beardsley finished in 6th place.Frequency ControlAll radios, including 2.4 GHz, had to bechecked into the transmitter impoundeach morning. Frequency control was astight as I have seen it. Even with all thetransmitter control, several planes wereshot down from frequency conflicts. Thecompetitors list shows 122 pilots, juniorand senior. Of that amount, ten wereflying 2.4 systems. Countries flying 2.4were Australia, Brazil, Israel, Norway andthe US. None of these pilots encountereda frequency control problem.IstanbulThe team manager, Jim Monaco, did itagain. The team drove back to Istanbulthe night before many had to get on aplane and fly home. Again, Jim Monacomade the arrangements. Several of usstayed for a couple of extra days. TheThe second bus, filled to the roof with plane boxes and suitcases.38 R/C Soaring Digest

Ben Clerx’ plane box and traveling workshop.The two boxes (temporarily) lost by British Airways.October 2008 39

hotel was across the fence from Sophia,across the street from the Blue Mosqueand the Roman Cistern, and just eightblocks from the Grand Bazaar. This is aBIG city with 14 million people and lotsand lots of things to see. We saw asmuch as we could see in two days. It wasan exceptional way to finish the trip.If you are reading this article andthinking about competing on a WorldChampionship level you are in for afantastic time. Making the podium is ona whole different level from what youhave experienced on a local contestlevel. The commitment of time, airplanes,equipment and money is BIG and worthevery penny.The only bummer of the whole tripwas British Airways. On the trip home,British Airways lost two airplane boxeswith a total of 11 planes in them. One ofBrendon’s planes was signed by many ofthe best pilots from around the world andis impossible to replace. British Airwayshas treated the entire issue as if it reallyis not their problem. I will never fly BritishAirways again. (Both boxes were foundat the end of August in an air cargowarehouse at SeaTac Airport. - Ed)I am sooooo tired. At the same time, Ican’t wait to do it again. Both MichaelKnight and Brendon Beardsley are youngenough to try it again.France in 2010, here we come!Additional information:1.For a List of who was flying what planeand radios see 2.Official website with all kinds ofinformation The US and German Junior Teams hangin’ out.3.A rather long thread on the F3J WC onRC Groups n40 R/C Soaring Digest

Above: Ordering at McD’s is easy as long as you stick to numbered meals.Right: The interior of the Grand Bazaar in Istanbul.Left: Our hotel for the F3J World Championships.October 2008 41

Wings with a Twis tSteve McKinlay, s.mckinlay@xtra.co.nz42 R/C Soaring Digest

first became aware of Pitcherons/I Wingerons not long after I first becameinterested in flying RC sailplanes in 2000.At the time, threads on RCGroups andelsewhere inspired my imagination ofwildly twisting, fast flying slopers. I hadno experience with flying sailplanes, butthat didn’t stop me dreaming of flyingthese high performance planes. Soonafter I bought my first RC plane (an EPPP51) and learnt the basics of flying. Myprogression of learning after that wassimilar to most, a couple of EPP planesbefore my first crunchy (a 2m Mefisto),my first molded plane and various otherplanes over the next six or so years.A little history first. As far as I have beenable to research, wingerons have beenaround for a long time with the 160" HegiSB10 wingeron in the late 1970’s alongwith the Sailplanes International Axel inEurope and the Bridgeman Snipe in theUS of around the same era being someof, if not the earliest designs using thiscontrol method. Others since then havemodified well known planes like theHobie Hawk and Sagitta to wingerondesign.The pitcheron control was invented as faras I can see by Ken Stuhr of VS Sailplanefame in the late 1980’s when he designedand built the now famous Rotor. Kendesigned and built what are consideredby many to be some of the finest (andnow rarest) examples of pitcherons andwingerons: the Rotor, Vmax and Xica.These slopers were responsible forinspiring others to design their own TWFplanes.The slopes around the Tri City areain Washington State (Eagle, Chandlerand Kiona Buttes) and the NorthernCalifornian coastal slopes are perhapsthe spiritual home of the TWF (twistywing fetish) designs. This is where Kenand others such as Charlie Richardsonand Harris Nelson designed, built andflew their planes and made them famous.Since then others have fallen in love withthe sleek designs and high performanceand have designed and built their own,some going onto commercial production.Examples include the Charlie RichardsonTurbo, Tom Feldvebel’s Kestrel, SigSamurai, Harris Nelson’s Shrike andothers including Harley Michaelis’ Orca.Recently there has been renewed interestin production models including someshort run of kits such as the re-releasedShrike and Shredder, the Pica and Ultron.The term TWF refers to both twisty wingtypes, and was thought up by BrianCourtice in his Ultron build thread onRCGroups. It was taken from a relatedterm: PNF (or pointy nose fetish) whichwas coined by Brian Laird to describethe predilection for pointy fuses of thefast and heavy planes which originated inNorthern California.Other priorities overtook my life (I wasfinishing Uni at the time and just startingmy first serious job and lost a lot ofmy spare time) though I still kept flyingwhenever possible. I had come acrossthe Orca, a 70" pitcheron designed andbuilt by Harley Michaelis – a well knownsailplane designer and builder (includingthe Genie line and the RDS) and fell inlove with the sleek purposeful design,but never figured I would be able to buildone.Years later, after some more experiencein flying and building, I came across theplans, Harley was generous enough tomake them publicly available with thehelp of his friend and TWF guru JayDecker. The design was for a slab sidedfuse made from wood, ply and balsa andcovered with fiberglass. At the time, I hadlittle experience in building planes fromscratch, but was playing around withbuilding wings with a vacuum bag. Theplan appealed to me in a number of ways– it was a beautiful plane, it looked easyenough to build, I could attempt my firstcomplete vac bagged wings, and it was apitcheron. So I printed the plans, boughtthe wood as well as some high powerservos and started to build.It came together much easier than I wasexpecting (with a lot of help via a buildthread on RCGroups). I’m no masterbuilder but I found the plans easy enoughto understand and managed to getthrough without any major dramas.I did change the plans in one crucialway – a fellow RCGer had generouslydonated a pair of beautiful machinedOctober 2008 43

aluminium bell cranks to operate the wings. These weredesigned and machined by Doug Boyd and were installed withthe drive pins at the trailing edge of the wing. Other than thedrive system for the wings, the fuselage was built the same asthe plans. It did come out a little heavier than I was hoping, butit proved to be very strong.The wings were built a little differently than the plans. I followedJay Decker’s article on installing sparless joiners for twisty wingplanes (see www.slopeflyer.com/artman/pubish/twf> for more details). The cores were theoriginal e374 thinned to about 8% and cut from polystyrene andsheeted with balsa and 3oz fiberglass. The finished wingloadingcame out at 24oz/sq ft, meaning that it was by far the heaviestand fastest plane I had ever seen or built.About half way through the build, I was lucky enough toconvince my fiancée that I needed another pitcheron, andmanaged to get onto the list for the last run of the Sky KingsRC Products Shrike, a re-release of the famous Harris Nelson60" pitcheron. As I was working in a winery in New Zealand,I wanted to finish and maiden the Orca before harvest began(mid-March) as I was working flat out for the six or so weeksthat harvest runs. Thankfully I was able to complete it in timeand managed to have a number of flights before the harvestbegan.To say that I was nervous before my maiden would be anunderstatement. I had set up the controls as per Harley’s plans,but never having flown, let alone seen, a pitcheron before, I wasunsure what to expect – other than it would be a handful tryingto land (no flaps/spoilers and a heavy slippery design).The day of the maiden saw my flying partner and I at the topof our favourite slope in 45kph winds. I’d flown my Destiny andseen my friend maiden his heavy PSS Hawker Hunter so I waspretty sure that it would be able to fly.Detail of the wingeron/pitcheron system.44 R/C Soaring Digest

We agreed that Dan would launch for me,both so that I could have both hands onthe controls in the event of a mishap andso that it would receive a proper throw.I tested the controls with Dan hangingonto the plane at the lip of the slope – allthrows were correct and felt good, so Igave him the nod.A heave into the lift made it pitch upviolently and I had a few thunderousheartbeats before I managed to getit down safely with little damage. Wepatched up the damage and I dialedin some down trim before Dan walkedfurther down the slope and threw itoff again. This time I was ready for thesudden lift and kept it under control,though I did need every bit of downtrim to get it flying level. The lift washuge, probably nothing compared tosomewhere like Eagle Butte, but for me itwas a wonderful moment. A scratch builthigh performance plane flown in big lift –just slightly addictive!!!The plane felt at home in the air, theheavy AUW meant that it cut through theturbulence that I had struggled with whenflying my Destiny, and meant that it flewfast.All the controls felt very precise, almostdigital like, so much so that after only afew passes I did a fast pass and rolled toinverted six feet across the front of theslope.Rolls were fast and smooth, while theelevator was smooth without being overresponsive. To be honest, I only flew itfor about 10 or 15 minutes. The releaseof adrenalin was too much and I beganto think, somewhat nervously, aboutlanding.I ran a couple of approaches to getthe feel of the landing zone and howthe plane felt in the rough turbulent air.The first was a little high, however thesecond from the opposite directionfelt right if a little bumpy, so I put herdown firmly. Stories of tip stalling whileloitering over the LZ were in the back ofmy mind. To say I was elated would bean understatement, we were both veryhappy with the day and left to go home,talking nonstop. Two successful maidensleft us both wired.Sometime after the maiden, I founda new slope that put all our others toshame. With 150m or so of steep front,600m wide, a smooth laminar LZ withfew rocks, and the approaches for thewind were super smooth. Nothing acrossthe river flats to impede the flow of airfor kilometers, this slope quickly becameknown as the “Mecca.”While the wind wasn’t as strong as theday of the maiden, there were somevery strong thermals cycling through. Ilaunched — no easy feat by myself —into some great lift and spent the next15 minutes or so doing endless pumps,aerobatics and speed runs.One thermal I found gave me some niceheight for a speed run across the slope,so I put the nose down and let the planegain some speed. About 50m before Iwas going to level out, one of the wingsfolded in the blink of an eye, and the fusewent into a ballistic trajectory headingsouth. I didn’t see the landing, but wassure I would be picking up the pieces toput in plastic bag, so I was shocked tosee that there was almost no damage.The horizontal tail surface had broken offthe fin, and there was a small crack in thefuse. Other than that, there was a brownscar where the nose had dug a hole25cm into the hard dirt. The wings weredifferent,. The one that had folded wascompletely beyond recovery, so I packedup and went home depressed...Harvest came and went, my Shrikearrived, was built, maidened and flowna lot, but always in the back of my mindwas the fuselage of my Orca sitting in themidst of the spare/model room waitingfor a new set of wings.A local RCGer was generous enoughto volunteer his time, expertise andequipment to help me build another setof wings. I settled on a slightly largerwingspan (2m), both to give me a largerplane and to bring the wingloading down,but I stuck with the original 8% e374.This time I cut the cores from blue foamand vac bagged on white poplar sheetingwith 3/4oz glass and a carbon golf clubshaft spar out to 50% span. They cameOctober 2008 45

ShrikeOrca and ShrikeOrca46 R/C Soaring Digest

out light and stiff and looked up tohandling full speed dives.We built the wings just before my fiancéeand I moved back to Australia, sounfortunately my mentor was unable tosee it fly.Here where we have based ourselves inNorth East Victoria, slopes big enoughand with a nice LZ to land a slipperyplane are few and far between. Thenthe winds have to come from the rightdirection, and unfortunately they are alsorare, so it was some time before I waslucky enough to get some wind that wasgood enough for a maiden.The slope I maidened it for the secondtime is a superb one, a huge meteorcrater many kilometers across and 200mor so of steep slope.I had already flown my heavy Destiny, sofelt confident enough to launch the Orca.A few dry run launches to check thedirection of the throws and get my armmoving again and she was away.Although the lift wasn’t big, there wasenough to get some height for somegentle speed passes and carving turns.Since it had been some time since theoriginal had flown, it was so nice to seeit in the air again and hear the turbinewhistle as she flew past. The lift wasgood despite the low wind-speed, so thenoise was very clear and very differentfrom any other plane I’ve heard.The lighter wingloading was apparent— down to a little over 18oz/sq foot —though I was unable to get more thanabout 75m above the slope. A successfulif bumpy landing meant that I wasecstatic. I was taking her home in onepiece again.I then rebuilt the heavy tail and managedto shave another few ounces off thewingloading (down to just over 16oz/sq foot) so the second time I flew it indecent lift, I was able to really wring itout.Fast passes were addictive, half pipeswere endless, and the energy retentionwas excellent, with endless Cuban 8’sOctober 2008 47

eing a highlight. There were a few largethermals that passed through giving meenough height to do some really fastruns with no sight of any wing flex. Again,the feeling of the controls was of digitalresponse and smoothness, fast enoughfor aerobatics and drill-like rolls, butaccurate enough for precision flying.To me flying a pitcheron feels like a wellsetup plank wing. You can’t “yank andbank” it, but it has to be flown around theturn to get the most out of it. Yes, I knowtheoretically it should be no different toa conventional plane, but that’s how itfeels. They like to be flown fast and nothang around in the lift. As clean modelswith little drag, they quickly accelerateand hold their speed excellently.I was shocked the first time I handlaunchedmy Shrike on a football pitchat how quickly it accelerated out of theturns. On a good slope in decent lift afew well strung together turns quicklypiles on the speed.I’ve yet to have either my Shrike or Orcadrop a wingtip, and they thermal aswell as my molded HLG. The Shrike is alighter, smaller pitcheron (60" wingspanand AUW of 21 ounces) but as it is nolonger available it is limited to slopeswith excellent LZ’s and good lift. It alsothermals superbly and has a good turnof speed for such a low wingloading.The only downside to the Shrike is thatit does take some planning to land itconsistently, such a drag free designmeans that it glides forever.Being a V-tail, it possible to pack it downinto a case about the same size as asmall-bore rifle. This is perhaps the bestperforming plane I own, being able tofly in thermals along with up to 80kphwinds without ballast at a wing-loading ofaround 11oz/sq foot.I love both of my TWF planes, but myShrike doesn’t have the soul that theOrca does. It’s a bit like comparing ahigh performance F1 car to a muscle car.The muscle car may not have the highperformance of the F1, but the musclecar wins hands down in that they havetheir own “character.”I am now planning a scratch-built 100"wingeron of my own design with a splitrudder and pop-up canopy for airbrakes.Having been bitten by the twisty wingbug, it is impossible to recover: thespeed, precision and lightning rollsare highly addictive. These little knownplanes are the thoroughbred speedstersof the sky, and I’m sure my arsenal ofplanes will always include at least one.Thanks to Jay Decker and Doug Boydfor checking my history section andFrank Slaughter for the photo of HarleyMichaelis’ Orca flying during the 2007Tri-Cities Six Pack event.GlossaryPitcheron: Both wings rotate in the samedirection for elevator input and oppositedirection for aileron input. There is NOelevator or aileron surface. The wholewing rotates in response to the input.Wingeron: Wings rotate in oppositedirection for aileron control, but the planehas a normal elevator, either all moving orarticulated.Both can have a normally functioningrudder and can often be built as eitherconfiguration.Websites Plane reviews anddedicated TWF construction articles andplans written by guru Jay Decker. Theplans for the VS line of pitcheron andwingeron planes are available via thiswebsite courtesy of Ken Stuhr.www.genie.rchomepage.com>Orca Plans OriginalOrca build thread with Video of maiden Re-build ofOrca.n48 R/C Soaring Digest

Uncle Sydney’s gossip columnMiles and Storks meanSmiles and TurkeySydney Lenssen, sydney.lenssen@virgin.netLucky enough to be in Istanbul twoweeks ago, Murat Esibatir and PhilipKolb kindly invited me to their local twometrecompetition.The club’s field is about an hour out ofthe city and almost under the flight pathof the city’s second airport on the Asianside of the Bosporus.No surprise, the field is also a fewminutes away from the new fineworxfactory where “Miles,” the new two-metrecompetition glider, is coming off theproduction line, first of a series of modelsplanned to be manufactured by thisdynamic duo.What a fantastic fun day was enjoyed byall, about 24 pilots, friends, girlfriends,children and helpers, in weather whichranged from 30 to 35 degree Centigrade,scarcely a cloud in the sky, thermalsaplenty and a vital need to drink as muchwater as possible.Philip Kolb with a characteristic overarm launch, this time from abungee with the new cool “Miles”, the all-wooden 2 metre competitionglider from fineworx, the new model manufacturer in Turkey.October 2008 49

A clutch of Miles, the new two metre class glider produced by MuratEsibatir and Philip Kolb, and already a hit with the Turks. Kits forwhat has been described as a “small F3J model dressed in sheep’sclothing” are available in the US from Kennedy Composites.First an outline of Turkey’s two metrerules. The model must be all woodand no composites, only rudder andelevator/v-tail and two servos, launch isby bungee - 30 metres of cotton coveredrubber to limit extension to roughly twicenormal length - and 100 metres of line.Pilots fly man-on-man in 9 minute slotswith a maximum allowable flight time ofsix minutes. A standard F3J landing tapeis used to score landings and overflightsare penalised by deducting the numberof seconds over, up to a 30 secondmaximum. Pilots can launch as oftenas they wish, the last flight and landingcounts as the score.Toughest part of the contest is to landaccurately and close to the 6 minutetarget. With only two controls, it is noteasy to get the glider down out of athermal and slow it down to a pace whichallows you to land on the spot withoutdamaging your model. From what I hear,the United States has a two-metre class,still popular for club contests, and therea third servo is permitted and used tocontrol a spoiler. The option of a spoilerwill become part of Turkey’s rules fornext year’s competitions.Many F3J pilots have visited Turkeyin recent years to compete at Riva onthe Black Sea coast and at Adapazariwhere the world championships wereheld this summer. They will vouch forthe high standard of organisation andfacilities which the Turks lay on. While not50 R/C Soaring Digest

quite as grand for this club competition,everybody on the field mucked in tomake sure that the event ran smoothly.Every pilot in the three slots per roundhad an independent timekeeper andscorecards, the computer churned outresults, when the timing system brokedown, a loudhailer was used to start andfinish slots and check that all pilots wereready. Regular breaks were called to eatand drink. Pilots went out to the line withtwo helpers, one to act as spotter andcount down the six minutes, and one toretrieve the bungee in case a second orthird launch was necessary and sort outany crossed lines.The standards of flying was very mixed.Everyone knew that Philip and Muratwere international standard, severalothers were well experienced whileothers were at various stages in thelearning process. Each slot had mixedabilities, rivalries were intense and ribbingand joking went all down the line.A number of the pilots had yet to beindoctrinated into Dave Thornburg’s“River of Air” guidelines. They persistedin pushing upwind where they wereconfident that the factory roofs weregoing to lift them to the clouds. OzgurVural is an experienced model helicopterand power flyer, but thermal flying isdifferent. He had yet to be convincedthat it is worth following a thermaldownwind. But after flying out his sixminutes in three consecutive rounds, withA few of the happy band of two-metre pilots at the end ofthe day, with the jet overhead on its approach to SabihaGokcen airport on the Asian side of Istanbul.October 2008 51

his spotter shouting “fly downwind,” he was convinced and hissmile was almost two metres wide!But the highlight of my day were the flocks of storks. At onepoint there were five separate darkish clouds of the majesticbirds spread across the sky from north to south, storksreturning to Africa across the Bosphorous from northernEurope. Each cloud paused almost stationary in the sky, athousand or more storks thermalling and gaining height beforebreaking away to catch the next batch of lift. How do they allcircle so closely, seemingly in random turmoil, certainly not allin the same direction, without any collision?But whether it’s one stork or a thousand, when they circle itmeans lift! Several of the two-metre models went up to jointhem, and again, even when models were in the thick of theflock and hard to distinguish and keep your eyes on, there wereno collisions.When Philip launched almost into the base of the flock, hecried: “I hope their radar is good,” and amazingly half a minutelater, I saw Philip’s model flying above the flock and to one side.I hope that a reader somewhere will explain this phenomenon.It appears that a well trimmed model glider will climb faster thanthe typical stork in the same thermal. I am confident that Naturehas blessed the stork with super thermal reading skills and finefeatheredaerofoils. If the stork is not climbing as fast as themodel, then either the bird did not want to climb fast in the liftor its wing loading was higher than the model.Whatever the explanation, the storks were a wonderful sight tosee and provided a wonderful bonus to super contest. nThe model is easy to spot as it breaks away from the flock inthis enlarged photo. The storks seem to be just as good atavoiding man-made objects as their own kith and kin!One of what was at one time five flocks of storksthermalling over Istanbul’s two metre class thermalglider contest, and not one collision. See if you canspot either of the two gliders in that lot!52 R/C Soaring Digest

October 2008 53

What a landing!Daniel Bizzera, Daniel_Bizzera@carrefour.com>Hello, friends.Here, I share some photos. In thoseyou can see me and my model, after alanding...Notice how the cone stayed fixed in theground!The Timekeeper did not know how tomeasure the distance to the base oflanding!!!Finally, he measured three meters fromthe nose of the model.A good landing for me.n54 R/C Soaring Digest

October 2008 55

Klingberg Wing 100RevisitedTom Nagel, tomnagel@iwaynet.net56 R/C Soaring Digest

Rol Klingberg built and flew hang gliders and flying wingsailplanes. You can find a picture on the internet of Rolpiloting his full scale flying wing hang glider, sitting in a hole ontop of the thing with his head sticking out, looking for all theworld like Santos Dumont getting ready to cross the Englishchannel in some alternate universe.All across America are there are two meter spruce and balsaKlingberg Wings, stuck up in the rafters of the basements of RCsailplaners — some still in the original box. Some folks swear bythem, and some folks still swear at Rol for kitting the darn thingin the first place.Somewhat less common is the Klingberg Wing 100, the balsaover-foamcore five servo floppy-winglet wonder from the early1990’s. This story is about my adventures with the KW 100. Butthe story starts a little earlier than that.I started flying RC in 1993, and soon after getting control ofmy Goldberg Sophisticated Lady I started looking around formy next plane. The 2M KW caught my eye. Due to my limitedbuilding skills, that was probably a mistake. I eventually got itinto the air, but it was truly a dog. The sliding tray mixer, as Ibuilt it, neither slid nor mixed. I got a computer radio and solvedthat problem. The 2M KW wallowed in flight, with adverse yawthat had to be seen to be believed. I learned about the floppywinglets on the big KW and fashioned some of those for the2M, and the plane became manageable in flight, but it was nota pretty thing to watch.I never thermaled the 2M KW, not even once. Its majorachievement in flight came on the slope over in Newark, Ohio,when it flew right through a Zagi LE and cut it in half. Oneday while bungee launching the KW, it achieved lock-out,spiral divergence and total destruction, faster than I can inputthose words into the word processor. I gleefully ripped out theelectronics and stuffed the tattered remains in a trash barrel.Thus, I find it hard to explain to myself why I wound up buyinga completely built KW 100 a couple of years later. I guess I justhave a thing for wings.—————Tom Hoopes of Sandy Utah had advertised his completelybuilt KW100 for sale on the RC Soaring Exchange. He offeredit complete with servos and battery at a very reasonable price.I had heard that Tom Hoopes was an immaculate builder, andwhen the big box arrived via UPS I was soon able to attest tothat. The cardboard shipping box itself was better built andbetter looking than any of the planes I had constructed to thatpoint. I still use that box to store and transport the KW100 tothis day.October 2008 57

Even before I had the big Klingberg programmed into my new JR radio, I puttook it to the Westerville Ohio RC show and entered it into the static displaycompetition. It won first prize in the sailplane division. Now it was time to tryto fly it.The KW has five servos: one each for the two elevons; one each for the twoflaps; and one servo in the radio compartment to slide the big Nicad batteryback and forth, so that the CG can be adjusted in flight. For some reason, Iwas having trouble getting the two flap servos to act in unison. We finally gotthat more or less straightened out, although to this day the two flaps drop atslightly different rates. As it turns out, that doesn’t matter much.Tom and his Klingberg Wing 100 at the thermalfield. Because there are no hand-holds, Tomdevised a rather clever foot pedal releasemechanism which works extremely well.58 R/C Soaring Digest

The KW 100 awaits another flight. Hey, is that a Flamingoid off the KW left wing?Don Harris kindly donated severalhours of his time helping me programthe KW100 onto my JR 783XP. TomHoopes sent me some long emails withsuggestions. All it took was the advice ofthese two experts and several eveningsof my time, and I was ready to go. (I don’tthink the folks at JR anticipated a flyingwing with dual flaps and an adjustableCG when they designed the 783.)One control that didn’t need any work atall was the floppy winglets. Rol Klingbergdevised a set of winglets that are free torotate outward only. A metal pin stopsthe inboard rotation. The intended effectof the floppy winglets is to eliminateadverse yaw. When I did the math towork up the KW100 specifications, I wassurprised how small the winglets actuallyare: each one is only 17 ½ square inches,equivalent to a square less than 4 ¼" by4 ¼". My Zagis had more winglet thatthat.After getting the controls sorted out, Iwaited for slope weather.And while we are waiting for slopeweather, this might be a good time torun down the specs for the big wing. Roldidn’t include any specs in his lengthyinstruction manual, so these are from myown measurements:Span -- 100" in three segments: a 30"center segment and two 35" outboardsegments.All of the electronics, battery, and servosare in the center section. Pushrods crossthe joint-line between the center sectionand the wing-tips to run the elevonson the outboard sections. If you arebuilding a KW100 today you might wantto consider Harley Michaelis’ RDS driversinstead of long, exposed pushrods.Wing area: about 1000 square inches.Aspect Ratio 10:1All up weight as built by Tom Hoopes:71.8 ounces or 4 ½ pounds.Wing loading: 10.33 ounces per squarefoot. A wing loading calculator at www.silentflight.net says this means the stallspeed will be about 16 mph.The whole thing breaks down and travelsin box 36" x22" x 9".For comparison purposes, a Maple LeafDesign Icon is 130" in span, has a wingarea of 1150 square inches, weighs 69 to75 ounces and has a wing loading of 9.5to 9.8 ounces per square foot.The plane has a single towhook, andI ultimately learned it winch launcheswith no difficulty, once you learn how. Ithas a small plywood landing skeg nearthe trailing edge at the wing root, andit turns out this is the part of the planeOctober 2008 59

most susceptible to damage. The skeg isrectangular, about 3 ½" long by 2" high.Tom Hoopes told me he broke it once,and I have busted it twice since then. IfI were building a new KW 100, I wouldtaper the leading edge of that skeg sothat it would still protect the flaps butwould not knife into the turf and getbroken.My first outing with the KW100 was tothe big slope at Plainfield, Ohio, a longgrassy ridge a couple of hundred feethigh, the remnant of a reclaimed stripmine operation. The ridge has sincebeen parceled out and sold off to homeowners, but back in the late 1990’s hanggliders and RC slopers flew there. Theslope was open, forgiving, possessedof a generous landing area, and so wideleft to right that you could fly even a largesailplane out of sight.I let Don Harris take the first flight. Wechecked to make sure the CG was runall the way forward, and I shoved theKW100 off into the wind while Don flew.It was all very smooth and unremarkable.Don didn’t try anything radical, justcruised around up and down the slope,doing turns away from the slope, andthen into the slope, checking the actionof the flaps, and just generally having afine time. I think it always pays to havesomeone with a couple of LSF 8 hourslope flights under their belt try out yourbeautiful new sloper.I got in a couple of flights that day, too.The big center section flaps really slowdown the big flying wing and allow easylandings. Just before touch-down I raisedthe flaps again, and the wing flopped intothe tall grass nice and easy.Ohio doesn’t have many big open slopes,and sadly the big Klingberg didn’t getout of the cardboard storage and travelbox very often. The plane was allegedlywinch launchable, but for the life of me Icouldn’t figure out how to hold the thingto launch it. Years passed while the KWlanguished in its cardboard box.The internet provided an answer. I sawan article about how to build a foot-pedalrelease mechanism for bungee or winchlaunching. Here is a YouTube video of adevice similar to the one I built.The launcher I built was made out ofcarefully selected one inch boards froma waterbed frame that I found in the alleyout behind the house when some dudemoved out of the apartments next door. Ipadded the rails with some leftover foamwater pipe insulation material. I think Ihave about $1.50 in the whole thing, theprice of the 12" bolt that the long footpedal pivots on. The launcher is 60" long,8" high, 9" wide (except for that big bolt)and sports a handy carrying handle onone side, right at the CG.There are three spikes: two in the rear tohold the rig from sliding forward, and onein the front to capture the tow ring on topof the chute. There is a big circular holein the front of the foot pedal. When youstomp on the foot pedal, the forward endcomes up and pushes the ring up off thefront pin, and off you go. There are onlytwo other essential pieces of equipmentto make the launcher work:A short tow line extension, looped ontothe ring on top of the chute. This runs toback to the tow hook under the plane.A trusted companion to run the winch foryou.At first I experimented using a high start,and using the foot pedal launcher tolaunch my trusty Mongo Jr. My Mongois set up to fly thermal and has a singletow hook just forward of the CG. The footrelease mechanism worked beautifully onthe Mongo Jr. But there is no off-switchon a high start, and the big KW justlooked sooooo beautiful that I couldn’tmake myself risk it to the bungee.More years passed. The KW sat patientlyin its cardboard box.Once a scrounged bed frame, now a Klingberg Wing 100 foot-pedal release mechanism.60 R/C Soaring Digest

October 2008 61

Launch! Tension the line, stomp on the launch mechanism, and it’s off!You can already see the ’wing rotating into a climb.Finally, last fall I recruited good friend BillHoelcher to run the winch for me, and Ihauled the KW and foot pedal launcherout the club’s new flying field. Late in theday we gave it a try. We lined up directlyinto the wind and checked throws for thecontrol surfaces. The CG control wasfull forward. Bill tensioned up the club’ssecond-line winch (The Wimpy Winch ofthe West as we call it). At Bill’s command,I hit the foot pedal and the KW100zoomed off the launch rails.That first launch was smooth, fast andlow. Bill and I have since learned how tolaunch a bit higher, but even at its bestthe KW100 does not do the near verticallaunches that we are used to seeingfrom our sailplanes. I flew around thefield a couple of times, dropped the flapsand landed. We did a couple of morelaunches with similar results. It was toolate in the day to find decent thermals,so we called it a day, happy with the firstwinch launches, only a decade after theKW’s purchase.(I should add here a note about Bill’swinch technique. The Wimpy Winch ofthe West is an old second hand unit, andbelt driven. It will launch large sailplanes,but it is not a zoomer. Bill just tensions62 R/C Soaring Digest

Flaps down!October 2008 63

up the line, and then stomps on the winch pedal until the beltslips. Then I hit the foot pedal release; away she goes.This summer we gave it another try. Our launches were gettingsuccessively better, higher with a nice zoom off the end, but stillno thermal flights.On one of the launches, with lots of altitude, we experimentedwith shifting the CG rearward a bit. Whoa Nelly! At about 25%of the travel on the CG control pot the KW suddenly becameunstable and stalled. I did a standard stall recovery while Billacted as my third hand and dialed the CG back to full forward.I was surprised how sensitive the KW was to CG shifts,especially since it is rock solid throughout the entire range offlap deployment. If you build a 100" KW, be cautious of that CGknob!On Sunday August 17, 2008, I finally thermaled the bigKlingberg Wing.It was a fine, high pressure summer day, with a light west windand cumulus clouds building during the afternoon. Thermalshad been tight, but powerful, and growing bigger and “poofier”as the day progressed. The club had been flying a Gnomecontest and generally fooling around all afternoon. Around 4 pmI finally set up the pedal launcher and got the KW out of its boxand ready to fly.On the first KW launch of the day I could see the big wingmarking thermals. I checked out my trims, decided to leave theCG adjusted full forward and made by customary precautionarylanding in the soy bean field. On the next launch I dropped theflaps a bit as soon as I hit a thermal bubble, and began a gentleturn. The KW climbed out and became the thermal bird that shehad been advertised to be.If you are going to fly your KW as a thermal bird, all I can say isjust follow the directions Rol Klingberg wrote in the manual, butwatch out for that aft CG:“To enter a thermal, simply start a gentle roll while adding insome down elevator. Then roll a little more briskly into thethermal and then ease in the required up elevator. Once you arein the turn, lower the flap and pull the CG back aft and up you’llgo. To achieve the best performance and more stability, in thethermal use about ¼ flap.”The 110" KW is definitely something different. Well built, it isa beauty to behold. It looks strange and wonderful in the sky.It slopes majestically, and if you can figure out how to winchlaunch it, will go up the line with no protests. The foot-pedallaunch release box is a bulky but effective solution.What next? I am going to program in some flap pre-sets forthermal flying. And I am going to pull the hatch off, observe theCG movement of the #5 servo, and make some index markson the CG control knob for future reference. Finally, I am goingto find out if my radio will program reverse differential into thechannel for the CG shift.My thanks to our club’s “flight surgeon,” Dr. Greg Bell, for takingsome of the photos used in this article.n64 R/C Soaring Digest

The FerengiRules of SoaringBy Peter Carr, WB3BQO@localnet.comMany of us have enjoyed the variousStar Trek series. The characters, suchas Spock and Seven of Nine, hold ourinterest to this day. Cloaked in all theintriquing gadgets and stunning visualsare some very profound pieces of advise.For example, when Spock departs, heusually says, “live long and prosper”. It’shard to argue with advise like that.And so it was that I found myself at theflying field not long ago. It was the usualcontest between my sailplanes and thethermals and I was looking for someguidance. As you can probably attest,the business of staying aloft by remotecontrol cries out for guidance.You may have been fascinated bythe Ferengi of the Deep Space Nineseries. For them “Profit” wasn’t amotivation, it was a religion. And, aswith all good religions, this one hadrules. They are listed on the Internet athttp://en.wikipedia.org/wiki/Rules_of_Aquisition. I read through the rules anddecided that there must be a hiddenmessage. After looking a little further Ifound that the author of the Rules wasIra Steven Behr, the Executive Producerof the series. Rumor has it that Ira wasalso a sailplane pilot. It seems that Irawas looking for quidance about soaringand developed the Rules while battlingturbulence along the eastern edge ofthe Rockies. It’s amazing what you’ll doto distract your mind when the air-sickbag is full. Now we know that sailplanepeople, whether full size or models, havea problem communicating their passionto unbelievers. Ira decided to substitutethe words “soaring” and “thermals” for“aquisition” and “profit.” This was howhe enhanced the TV series while helpinghis fellow pilots. While there are over 200Rules, it seems that they were not allwritten in sequence. Here, paraphrased,are the ones of greatest interest to us.* Once you have acquired a thermal....never give it up.* Never allow family to stand in the wayof flying.* A man is only worth the sum of hissailplanes.* Keep you ears open to the thermalsensortone.* Small details at the pilots briefing leadto big risks.* Opportunity plus instinct equals lift.* Soaring is eternal.* A thermal is a thermal... until a betterone comes along.* A thermal pilot without a thermal is nopilot at all.* Thermals are not guaranteed.* Never place friendship above good lift.* A wise man can hear lift in the wind.* Never make fun of a pilots sailplane.* Nothing is more important than yourhealth... except thermaling.* It never hurts to suck up to the ContestDirector.There you have it, my friends. You nowhave words to fly by. The next time youwatch Star Trek on TV keep in mind thatthere may be more to the plot than youimagine.Live long and thermal.nOctober 2008 65

TinamouCurtis Suter, suterc@msn.com66 R/C Soaring Digest

Tinamous are strictly neotropical birds— not found outside the tropics, andnowhere but in the Americas. They arelarge-bodied, almost tailless birds withslender necks and small heads, maybe30% larger than a bobwhite. They flybut prefer to walk or run, and they’resecretive.Well, so much for the name. MyTinamou is not secretive, as Ihave plans free for the asking and itlaunches, flies and lands very well!I’ve always been intrigued by flyingwings, especially swept flying wings. Sixyears ago I happened upon an articleabout a flying wing built and flown byHerk Stokely. See On The Wing... TheBook, Volume 2 #101 - “A Comparisonof Two Taillesss RC-HLG’s.” I wanted a bigger flying wing thanHerk’s little HLG wing and chose toenlarge his model to 100" wingspan.So I had cut the wing cores using whitebead foam as I intended to use balsasheeting for the skin. They did a greatjob cutting the cores, too!As all this was taking place I gotmarried, bought a house, and waspromoted at work. So best laid plansOctober 2008 67

I also learned that a flying wing can have flaps, and very effective ones at that!ended up in the rafters of the garage forfive years! The end of 2007 I had somefree time on my hands and needed aMontana winter project. So I got the foamcores down from the rafters, emailedHerk and started to think about what Ineeded to do to complete this project.Originally I wanted to launch her viaelectric assist and Herk suggested thatI reduce the amount of twist or washoutfrom 8 degrees to 4.5 due to the higherspeed of the model.Well, after five years and just like theweather, I changed my mind about howto launch the model and wanted to usea hi-start and to have a thermal durationmodel, thus I should have used theoriginal amount of twist. This begged thequestion, “How do you determine theproper amount of twist”?This is when I was led to the late Dr.Panknin, who devised a complex butfairly simple formula with the use of acalculator to determine the requiredtwist. I have since taken his work andmade a companion spreadsheet to“Sailplane Calc” called “Flying WingCalc” that will easily calculate the twist.The spreadsheet is available at THE DESIGNHerk wanted a nice flying thermal HLGflying wing and he was successful. Hechose the SD7037 airfoil for the centersection of the wing as this airfoil wasproven to have good characteristics. TheSD8020 was chosen for the outer portionof the wing as it’s a fully symmetricalairfoil and its sole purpose is to act asthe tail of the wing.A flying wing has a tail just like yourtypical tailed model; it’s just that thetail has a very short moment, i.e. thedistance from the wings quarter chordlocation to the tails quarter chordlocation. Remember from your basicaerodynamics class that the horizontaltail is used to counteract the negativepitching moment of the main wing byapplying a down force, thus pitching theleading edge of the wing up.The same thing needs to beaccomplished with a flying wing. In aswept wing this is done by twisting the68 R/C Soaring Digest

Tinamou SpecificationsSpan 95"Chord, rootAirfoil, root17”, not including bat tailSD7037Chord, tip 9.5"Airfoil, tipSweep angleWing AreaTwist (washout)CG locationWeightWing loadingEffective Wing loadingSD802025 degrees at 0.25 chord26.8 degrees at LE1235 in²4.5 degrees13.2" aft root LE,8% static margin77 ounces8.98 oz/ft²11.67 oz/ft²Note: Effective wing loading is 30%greater, as part of the wing is acting asa tail.outer portion of the wings trailing edge up in relation to theleading edge, thus this applies a down balancing force tothe lifting section of the wing.This is different than with a reflexed airfoil that raises thetrailing edge of the airfoil across the entire span, creating avery low negative pitching moment. Very little, if any, twist isrequired if a reflexed airfoil is used.Some may ask why not use a reflexed airfoil over the entirespan. Well, what I’ve learned during this process is that areflexed airfoil will suffer in its thermalling or lifting ability. Ibelieve that reflexed airfoils are suited more to slope soaring,electrics, unswept plank type wings or where higher speedis desired. I was looking for a thermal duration model.Herk then chose a planform, sweepback angle, taper ratioand aspect ratio for his wing. With all of this informationhe was able place this information into Dr. Panknin’sformulas and determine the required twist angle that wasrequired to be built into the wing. It’s important to note thatDr. Panknin’s formulas require a linear twist. The first 10" ofmy wing are pure SD7037 with no transition to the SD8020as I wanted a good lifting section in the center of the wing.One of the many things I enjoy about aviation is that I amalways learning. During this endeavor I learned about airfoilpitching moments, airfoil zero lift angles, the middle effect,the difference between reflexed and non-reflexed airfoils,and how to determine wing twist to longitudinally balance aflying wing. I also learned that a flying wing can have flaps,and very effective ones at that!See the table on the left for Tinamou’s specifications.October 2008 69

THE BUILDThe basic building of the wing is quitesimple. I took the cores that wereprofessionally cut and chose to use1/16" balsa wood as the skin with 0.2ounce carbon fiber in between fortorsional strength. The spar is .007carbon tape top and bottom. I usedpolyurethane Gorilla glue to attach thebalsa to the cores via my home madevacuum bag. I can’t take credit forthis method as it was done by TerryBrox and an excellent review is onhis website .Proof of how strong his wing is canbe found by clicking on “Misc Stuff.”I thought this would be plenty strongfor what I needed. The entire centersection top and bottom is fiberglassedwith three layers of .75 ounce clothstarting where the bat tail ends at thetrailing edge. Each layer is progressivelysmaller in span.The radio gear is mounted in a verysimple manner. The battery and receiverare cut out of the top of the foamnear the leading edge. The servosare mounted underneath the wing inpockets cut out of the foam; they arecentered on their respective surfaces.I placed hollow pushrod tubes in thewing prior to applying the sheeting sothe servo wires were easy to route tothe center of the wing. Here you can seeThe radio gear is mounted in a very simple manner.Typical wing joiner. Basswood box, the rectangular carbon rod is six inches long.70 R/C Soaring Digest

The finished tip panel ready for sheeting showing, spar(black line), wing joiners (wrapped wood pieces), and servowire tube (red).Vacuum bagging with MityVac hand held brake bleed kit.where the ’chute servo and drogue ’chuteare placed. More on the ’chute later.I couldn’t transport the wing at 100"so I made removable wingtips. I builta basswood box that could receive arectangular carbon fiber rod and simplytape the panels together prior to flight.It’s worked flawlessly.The carbon rod is six inches long andtapers are cut into the ends of the boxto transfer the loads to the wing skins.I chose the length of the outer panel onwhat I estimated that I needed for elevonsize versus the inner section that wouldbe used for flaps.The photo above shows the completedouter tip. I used 1/8" hard balsa ribs atthe root and tip. The tiplets are 1/8" balsaand fiberglassed to the end of this panel.For sizing I use the TLAR method — ThatLooks About Right. The black line is .007carbon fiber tape as a spar and the redtube is for the servo wires. This panel isready to be sheeted.The photo above right shows an outerwing panel in the vacuum bag. I useda Space Bag (storage type bag) and aMityVac hand held brake bleed kit toremove the air. I easily obtained 7lbsper square inch of pressure overnight.However, the Space Bag won’t holdmuch more with this setup. I’ve used theMityVac system with a different bag andeasily held 15 inches overnight.Herk suggested a skeg in the aft centerof the wing to keep the flaps off theground during landing and something tohold on to during launch. This has alsoproven to be very effective and simple.I used a center 1/8" plywood rib to jointhe wings halves to and the skeg isOctober 2008 71

cut as one piece with this rib whichincreases the skegs strength.There is an effect called The MiddleEffect. In short this effect is the loss oflift at the center of a swept wing due tothe detrimental interaction of vorticesat the center of the wing. To counteractthis, a so called “bat tail” helps incompensating for this loss of lift. Thebat tail is shown in the photos on thenext page. You can see the raisedtriangular area built up over the centersection, that’s the bat tail.You may read more about it the effect atOn The Wing…The Book, Volume 2 #86,“The Middle Effect” There are two tow hooks placedapproximately five inches each side ofthe center of the root. The left photoon the next page shows the hardwoodblocks I inserted in the foam core. Theblock is full depth so the loads aretransferred to the main wing sheeting.I made a bridle that attaches to themain hi-start chute, it has two rings thatattach to the wings hooks and anotherring that slides on the harness (string)and this ring is attached to the hi-startparachute.The skeg and bat tail.72 R/C Soaring Digest

One of the two tow hook blocks installed in the wings.These are full depth so the loads are transferred to thewing skins.The drogue ’chute and associated servo linkage.The wings tow hooks are placed 1/2inch forward of the balance locationwhich is 4% MAC forward of the balancepoint. This seems too far forward butany further aft and the launch sufferedin height and would periodically pop offduring launch. The launches have beena non-event, perfectly straight up the histart.The initial launch is what concernedme most prior to the first flight but thelack of sleep was unwarranted.THE ’CHUTEThis hobby is supposed to be fun so Iadded a drogue ’chute. I saw this on afriend’s Graupner SB13 flying wing, soI thought the idea would be great to tryon my wing. There was room for a ’chutein the area that made up the bat tail. SoI simply made a hatch with a releasemechanism. The aft part of the hatchis held in place with two plywood tabsthat slip under the top sheeting and thefront of the hatch has a small balsa blockglued underneath with a hole drilled in itthat accepts a plastic pushrod.At the end of the ’chute I tied a loop ofstring and inserted it from left to rightthrough a hole in the center plywoodbulkhead and when the pushrod isinserted this holds the ’chute in place.See the photo above right. The pushrodgoes through the loop and extends pastthe hole in the rib into the balsa blockOctober 2008 73

Jeff Vrba launching Tinamou at the Alpine Soaring Adventure Joseph Oregon. Note the wing fences are still in place.74 R/C Soaring Digest

in the hatch, thus holding the hatch inplace.Since the ’chute fits snuggly in itscompartment when the hatch is closed, itapplies a little pressure to the hatch andwhen released by the servo this allowsthe front edge to pop up allowing airflowto blow the hatch off the wing. The ’chuteis attached to the hatch thus it deploysthe ’chute.The servo has two actuations: 1. Duringthe first half of the movement of theservo the pushrod pulls towards the noseof the wing releasing the hatch, but notfar enough to expose the hole cut intothe rib, as this would release the ’chute.2. The second half of the actuationexposes the hole in the rib, releasing theloop of string and allowing the ’chute tobe emergency jettisoned.Also shown in this photo is the root riband skeg that’s cut as the one piece of1/8” plywood.The ’chute is somewhat effective butnowhere close to effective as the flaps.The ’chute is big in the “Wow!” factor,though!Here’s a video demonstration of the’chute: .FLYINGCurtis! Why did you name this beautifulmodel, that flies with the grace andbeauty of an Albatross, after a shy semiflightlessjungle bird that probably has thesame glide ratio as your transmitter?— Herk StokelyThe launches are a non-event and seemto have launch heights similar to my otherthermal duration models.The launches off the hi-start are a littledifferent than my tailed gliders as youdon’t lean back and give her a heftythrow with forward force. She should beheld with one hand by the skeg slightlynose high about waist level and the otherhand holding the trailing edge to keepher level. When you’re ready to launchyou lift her straight up about 12" and letgo at the top of the lift, slightly raising thenose during the lift.Tinamou will go straight up the launchwith very little correction required. Shedoesn’t seem to zoom off the launch aswell as other thermal duration models.She thermals well, but detecting lift willtake a lot of practice as the tail momentis short and it’s difficult to see changes inpitch.There is a bit of yawing during flight andturns but it’s negligible.The stall is quite sharp and will catchyou by surprise if you crank too much upelevator in a turn. It takes about 1½ turnsfor the recovery.I’ve tried wing fences and at first Ithought there was a significant differenceOctober 2008 75

76 R/C Soaring Digest

in handling, but I’ve since removed themand haven’t noticed a significant changewith our without them except the stallisn’t as abrupt with the fences.At times I wish I had a little more elevatorcontrol in order to crank her tighteraround a turn without feeling I may stallher. Finesse is key in flying her, more sothan with my other TD ships as a lighthand on the elevator is required. Thismay be solved with moving the balancepoint further aft and adding the flapsto work as elevators. Thus more flighttesting is in order.The model was balanced at 8% staticmargin for the first few flights and latermoved back to 3% which proved to betoo far aft during the low speed highangle of attack landing portion of theflight. She really got overly pitch sensitiveduring landing.I’ve since moved the balance point backto 8% as she launches, soars and landsvery well.The landings are easy. She really slowsdown well with the large flap area andwith more practice spot landings arequite possible. F3J type landings havebeen obtainable from the first flight,however the USA style of precisionlandings will take more practice.CHANGES I’D MAKE IF I WERE TOBUILD ANOTHERSince the twist was reduced for anelectric model I chose to increase thewing sweep from 22.5 degrees to 25degrees at the quarter chord point whicheffectively increased the amount of twist.This reduced the overall wingspan to 95".I’m currently flying with approximately1/8" of reflex to maintain a nice thermalspeed.So if I were to build another Tinamou I’dchange the amount of twist from the 4.5degrees to the 8 degrees Herk originallyused. I’d also change where I have thewings joined, making the elevons longerand the flaps shorter, perhaps a 20%increase in elevon span.I’d probably leave the ’chute out as ittook quite a while to get it rigged properlyand the flaps are way more effective.I also would like to try different nonreflexedairfoils, such as the excellentDrela airfoils and perhaps a little bithigher aspect ratio.But these would be the only changes. I’mso very pleased with how easily she builtand how well she flies. Herk Stokely andDr. Panknin really know what they aredoing!Perhaps in the near future I may make aremovable fuselage pod that houses anelectric motor in the nose. The pod canbe held in place by slipping over the nosethen attached to the skeg. It’d be a verysimple on/off arrangement.CREDITSThere are a lot of people I’d like tothank, beginning with Herk Stokely whopatiently answered my daily emails formonths. Also Jeff Vrba, Jim Cooney,Shawn Keller, Norm Masters and thefolks at RCGroups.Photos and videos courtesy of JimCooney, Shawn Keller, Jeff Vrba andmyself.There is a build thread at RCGroups ifyou’re interested. VIDEOS’Chute video Flight video compilation My website: nOctober 2008 77

CampbelLGreg Potter, mrgregpotter@hotmail.comMy wife and I are raising a guide dog puppyfrom the South Australian Royal Society for the Blind(RSB). We got him when he was nine weeks old andnow he is nine months old and near fully grown. He is ablack Golden Retriever/Labrador cross especially bredfor the RSB and his name is Campbell.I took him to the flying field for a practicesession some months ago so he could have a run in thepaddock and maybe see some farm animals (usuallysheep).When I walked to retrieve the winch line hewould trot along with me and then when I picked upthe parachute he would try and grab it from me, so I lethim carry it. At that age he was not strong enough topull the line back against the friction of the winch andthe turnaround pulley, so I would take the strain and lethim carry the chute.After about three sessions like this he had growna bit stronger and was able to pull the line back underhis own steam.Now he does the whole retrieve on his own.When I am about to launch he sits at my feet with hiseyes fixed on the parachute. Once I have launched hesits looking towards the turnaround until he sees thechute floating to the ground. Once he has spotted it heheads off at full gallop, grabs the chute and returns itto the winch.If I am flying with a hi-start he does the sameand he is now strong enough to stretch the line backto the point where I launch from.Frank Slaughter took these photos of Campbell atour recent local club RES competition.n78 R/C Soaring Digest

October 2008 79