Review of the July 2004 Flying Wing workshop - Mat's

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From there, the presentationmoved on to the actual designprocess. This is the one areawhere the expertise of modelersturned out to be invaluable to theongoing discussion. Compared tothose involved with full sizeaircraft, modelers tend to design,build and fly a much largernumber of aircraft over a giventime span. This provides anenormous body of first handevidence for what does and doesnot work in practice. And Markand Bill had arrived with a largemental store of ideas fromtechnical papers, magazinearticles, and personal experienceregarding tailless planforms.The last portion of the workshopinvolved the future of taillessaircraft. Projected improvementsin design and construction, andthe advances in performancewhich are expected to result,were balanced with theacceptance of tailless aircraft bythe public/consumer.Mark and Bill came away fromthe workshop with a number ofideas for tailless designs,predominantly involvingplanforms with quarter chordlines which are perpendicular tothe aircraft centerline or slightlyswept forward.As mentioned in prior columns,such a planform, with taper,provides a large arm for theelevator function and moves theailerons to a position closer to theCG, allowing use of differentialwithout adversely affecting pitch.If the aspect ratio is held to underten, stall characteristics are quitebenign and the Reynolds numbersare larger. Additionally, taillessaircraft of this type are quiteeasily constructed, can be verylight, and can be designed to haveminimal drag. All of this meansan expanded speed range, ease ofcontrol, and excellent thermalability.Mat, until recently, had beenflying his Monarch and thrillingin his ability to thermal well invery small areas of lift. Whenflying the Monarch, the pilot isalmost entirely out in the open,and subject to feeling the airwarm and cool, smelling thepollen being lifted by thermals,and having to wipe spider websfrom his or her glasses. Matexplains that flying the Monarchis the closest thing to actuallybeing a bird that one can imagine.Jim flew his own Monarch atHarris Hill a few years ago andsurprised everyone with a flightMat Redsell takes his Monarch up on auto tow. This launch methodis quite inexpensive. A strain gauge readout visible to the drivermakes sure the line tension remains consistent.Photo by Bill Kuhlman taken during the May 2000 workshop.2 R/C Soaring Digest
Mike Couts at the controls as the Pioneer II-D starts its aerotow toaltitude. This ’ship originally belonged to Lloyd Watson who hadpurchased it in nearly complete form from another owner. TheMarske Flying Wings team rebuilt the entire aircraft. The wingsurfaces were contoured to match the original airfoil and thefuselage underwent some modifications, including addition of anose wheel. Wing tip extensions were added, increasing the wingspan to just over 15 meters. Not readily apparent in this photo arethe fences which separate the inner edge of the elevator from thefuselage fillet. This addittion nearly eliminated the separatedturbulent flow at the aft end of the fuslelage. Photo by Bill Kuhlman/in excess of four hours from areasonable launch height.Jim and Mat have recentlyexperimented with a moveableCG for the Pioneer II-D. Thisopens even more vistas, as trimdrag is substantially reduced. Aten pound weight has beeninstalled, and it travels the lengthof the fuselage inside a tube,pulled along by a continuouscable attached to a rotary dial.The weight is slid forward forhigh speed cruising, to the rearfor thermalling.When Mike Couts landed thePioneer after the workshopdemonstration flight, it seemedlike the rollout was extremelylong. Mike later related that oncethe nose wheel touches theground, the glider just continuesto travel in a straight line, and it’seasy to run off the runway if theaircraft is canted on landing dueto a cross-wind. When the mainwheel touched the ground, Mikehad simply moved the weight tothe extreme rear of the aircraftand was able to hold the nosewheel off the ground for anextended run. Rudder authoritywas good enough that he couldsteer the aircraft down nearly theentire length of the runway.Was the workshop worthwhile?Bill and Mark agree they learneda lot from the workshop,particularly because of the varieddisciplines involved in thefrequent discussions both duringthe workshop and during breaks.Additionally, watching theadvanced Pioneer II-D fly was anawesome experience.Mark is currently in the laststages of designing a TD ’wingwhich he hopes to campaign inlocal contests, and Bill is ready tostart building two competitionaircraft for the 2005 Visalia Fallfestival — a two meter and anunlimited.The one other item which Markand Bill agree on is the need forscale models for preliminaryflight testing of a new design andthe desire to construct scalemodels just because it’s so cool tobe flying the closest thing to a fullsize aircraft without leaving theground. In fact, Marske FlyingWings is well on the way tobuilding a quarter scale PioneerIV. And a future “On the’Wing...” column will give detailsof the Monarch G, in hopes anR/C Soaring Digest reader willtake on the challenge.Until next time...January 2005 3
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Review of the July 2004 Flying Wing workshop - Mat's

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