Page 1October 2003

October, 2003Vol. 20, No. 10

U.S.A. $3.50

R/C Soaring DigestPage 2

ABOUT RCSD

R/C Soaring Digest (RCSD) is a reader-written monthly publication for the R/C

sailplane enthusiast and has been publishedsince January, 1984. It is dedicated to sharingtechnical and educational information. Allmaterial contributed must be exclusive andoriginal and not infringe upon the copyrightsof others. It is the policy of RCSD to provideaccurate information. Please let us know ofany error that significantly affects themeaning of a story. Because we encouragenew ideas, the content of all articles, modeldesigns, press & news releases, etc., are theopinion of the author and may notnecessarily reflect those of RCSD. Weencourage anyone who wishes to obtainadditional information to contact the author.RCSD was founded by Jim Gray, lecturerand technical consultant.

RCSD should not be considered to endorseany advertised products or messagespertaining hereto. An advertising rate card isavailable for businesses, and clubs.

Feature ColumnistsBill & Bunny Kuhlman (B2),

Lee Murray, Tom Nagel, Mark Nankivil,Dave Register, Steve Savoie, Jerry Slates,

Greg Smith, Gordy Stahl

ArtworkGene Zika is the graphic artist

who designs the unique ZIKA clip art.

RCSD StaffJerry Slates - Editor/Technical EditorJudy Slates - Managing Editor, SubscriptionsLee Murray - RCSD Index/Database

(available on-line)Bill & Bunny Kuhlman - RCSD Web Masters

PayPal Coordinators

Copyright © 2003 R/C Soaring Digest.All rights reserved.

R/C Soaring Digest556 Funston Drive

Santa Rosa, CA 95407phone: (707) 578-7871

e-mail: rcsdigest@aol.comhttp://www.b2streamlines.com/RCSD.html

OTHER GOOD STUFF

19 Classified Ads - New Products17 Schedule of Special Events

Monthly Feature Photography & Web Version of the Printed Article (where appropriate)Highlights & Mailing Status of the Current IssueAbout RCSD..................................................................................... Subscription Information...................................................Advertising Rate Card (Adobe Acrobat PDF format).............................................RCSD Feature Columnists, Reporters, and Editors....................... (E-mail/web addresses, plus general information about their areas of interest)"Getting Started in RC Soaring" ........ Getting started guide - Adobe Acrobat PDF formatLinks to Organizations, Special Interest Groups & ClubsOn-Line Articles - Great articles originally written for the printed version of RCSD......................................... "Trimming Your Sailplane for Optimum Performance" by Brian Agnew.................................................................................................. "Flys Faster" by Dr. Michael Selig.............................. "The Square-Cube Law and Scaling for RC Sailplanes" by Dr. Michael Selig.................................. "Modifying & Building the MB Raven (Parts 1-4)" by Bill & Bunny Kuhlman............................................................. "Butterfly and Moth Airbrushing Tutorial" by Joedy DruliaBookshelf Listings - A listing of recently published books of interest to aeromodelers.Complete RCSD Index, 1984-2002

RCSD ON THE WEBhttp://www.b2streamlines.com/RCSD.html

TABLE OF CONTENTS

3 "Soaring Site" ....................................................................................... Judy SlatesEditorial ........................................................................................... F3J Team Selection Write-Up...................................................................................................... SOSS Aero Tow Event Photos...............................................................................................................................House of Balsa

4 "On The Wing..." ....................................................................... Bill & Bunny KuhlmanFlying Wing Design & Analysis .................................. Twist Distributions for Swept Wings, Part 5

12 Sailplane Tool & Adhesive Applications ........................................... Paula Garwood.........................................................................................Hidden Treasure in the Balsa Dungeon

14 "The Sloper's Resource" ...................................................................... Greg SmithSlope Flying Resources ............................................................................... Learning to Slope Fly

16 "Gordy's Travels" .................................................................................. Gordy StahlFlying Techniques .................................................................... Home in - On the Range... Check!

18 AMA .............................................................................................. Dr. Sandy FrankHow AMA Elections Work ........ Please read no further unless you are interested in AMA politics.

3 Cavazos Sailplane Design11 R/C Soaring Digest

Special Interest Groups19 Eastern Soaring League (ESL)19 International Scale Soaring Assoc.19 League of Silent Flight19 Sailplane Homebuilders Association19 T.W.I.T.T.19 Vintage Sailplane Association

Advertiser Index

Events13 Tangerine - FL

Don't forget to check out the RCSD web pages each month.Cover photographs are always available for viewing, and

usually available for downloading, as well. Special article .pdf filesare frequently available for a limited time, and of course our webmasters update the highlights and status information of each issueas it becomes available.

Page 3October 2003

TheSoaring

Site

MIDWEST SLOPECHALLENGE 2000

CR Aircraft Renegade takesto the sky over beautiful

Wilson Lake during the Mid-west Slope Challenge, a specialyearly event. Rich Loud isflying for the camera.

Photography by DaveGarwood, New York.

Back Cover

THE LAST FLING

An annual event in Oklahoma,the Last Fling is held by the

Tulsa RC Soaring Club. Jim &Mike enjoy this special event!

Photo by Dave Register,Oklahoma.

F3J Team Selection Write-up

Jim Bacus, Member of the ChicagoSOAR club, has done an in-depth

write-up on the F3J Team Selectioncomplete with photographs. It isavailable for viewing at:

http://www.jimbacus.net

SOSS Aero Tow Event Photos

Paul Naton<paul@radiocarbonart.com>, hasposted some excellent photos of theSOSS aero tow event held at atMontague.

http://radiocarbonart.com/Pages/zmontepicsone.html

http://radiocarbonart.com/Pages/zmontepicstwo.html

House of Balsa

We received a snail mail request from longtime subscriber, Joel Lefkowitz:

“Great article about House of Balsa2x6! I would like to purchase kit.Perhaps you could forward address ofmanufacturer to me in order to do so.”

Not knowing the answer to the ques-tion, we asked B^2 and received thefollowing response in short order!

House of Balsa10101 YUCCA ROAD

ADELANTO, CA 92301PHONE: 760-246-6462

They went on to say:

“We did a quick check and found thatTower carries the 2x4. They shouldhave the 2x6 as well, but it’s not intheir on-line catalog, at least that wecan find.

“Order direct from <http://www2.mailordercentral.com/

quantummodels/products.asp?dept=21&pagenumber=2.

Price is $29.95.

Happy Flying!Judy Slates

“Joel should be able to get a kit fromhis local hobby shop, by special orderif need be.

“There are a number of clubs whichuse the 2x6 as the kit in school aerocourses, and it’s the kit used in theBoeing intern program. Yeah, 60teenagers running around 60 Acres,each with their own airplane and radiogear... “

Special Thanks

There’s always a lot going on behindthe scenes. This past month, a specialthanks is in order for Dave Register,who tackled a complex editorial taskfor me. Thanks, Dave!

And Dave’s not the only one. TheRCSD team always seems to be therewhen I need them, lending theirtechnical expertise, answering com-puter questions, or sending somethingmy way that they think may be ofinterest to most if not all of the readers.For example, the first two items of thiseditorial were sent in by B^2. Thanksfor all each of you do!

And, then there’s Gordy. We alwaysseem to know which state he’s travel-ing through, next!

R/C Soaring DigestPage 4

bsquared@appleisp.nethttp://www.b2streamlines.com

Twist Distributions forSwept Wings, Part 5

The Horten twist distribution has been thefocus thus far, but it’s now time to take alook at the twist distributions formulatedby Irv Culver and Walter Panknin, makesome comparisons, and derive a fewconclusions.

The “middle effect”

First, a small digression is necessaryin order to understand one remain-

ing concept, the “middle effect.” TheHortens’ later designs includedgeometric modifications aimed atreducing or eliminating the “middleeffect.” Irv Culver’s twist distributionis specifically formulated to eliminatethe reduction in lift near the center of aswept back wing. Interestingly, theHortens and Culver are trying tocounter two different phenomena.

As the wing moves through the air, theair coming off the trailing edge isdeflected downward. This is called thedownwash. As the air approaches thewing, it moves up slightly to meet thewing. This is called the upwash. We’vealready illustrated these two propertiesin previous portions of this articleseries, pointing out the angle of attackis directly related to the position of thestagnation point.

If you look at an airfoil travelingthrough the air, you’ll see that the airmoving over the upper surface ismoving faster than the wing is movingthrough the air. So too, the air alongthe lower surface is moving slowerthan the wing is moving through theair. From a vector mathematics per-spective, if you subtract the velocity ofthe wing from the two air flows, the airover the upper surface is still movingfrom leading to trailing edge, but theair along the bottom of the wing ismoving backward toward the leadingedge. From this perspective, the air

“circulates” around the airfoil in aclockwise direction as a wing produc-ing lift moves right to left. The coeffi-cient of lift is directly proportional tothis circulation. See Figure 1.

According to Prandtl’s lifting linetheory, you can visualize a wingmoving through the air as simply aline connecting the two wing tipsalong the quarter chord line withhorseshoe shaped vortices comingfrom it and extending back to infinity.In this model, both downwash andupwash are accounted for: the airinside the vortices is being deflecteddownward, and the air outside thevortices is being deflected upward.The actual lifting line calculations,however, are both complex andextensive. Schrenk expanded Prandtl’slifting line theory to include taper,twist and control deflections, but notsweep. Multhopp expanded thistheoretical framework further, but stilldid not fully account for the effects ofsweep.

A swept wing can be viewed as aseries of connected small wings, theleading edge of each slightly behindthe leading edge of its inboard partnerand in front of the leading edge of itsoutboard partner. Each small wing hasan effect on the air flow of both itsinboard and outboard partner, but theeffect on the outboard partner is verymuch greater than the effect on theinboard partner. The upwash is notequal along the span but rather tendsto progressively increase over the moreoutboard segments. (We’ve illustratedthis concept in previous portions ofthis article series.)

Schrenk’s approximation does notaccurately portray a swept wing, andtherefore does not account for the lossof circulation and associated loss of liftat the root and the increase of circula-tion and associated increase of lift atthe wing tips.

Multhopp’s method of determining thelift distribution, which involvesestablished “control points” based on“central difference angles,” does notaccount for sweep either, but was usedby the Hortens as the best availablemodel at the time. The H-II was thefirst of the Horten aircraft to use a bell-shaped, sinx, lift distribution, anoutgrowth of the Multhopp paradigm.

The “middle effect” which is so often

talked about regarding the Hortendesigns is simply an artifact of thisinability to accurately predict thesweep induced changes in circulation,specifically a loss of lift at the center.This middle effect is strictly an artifactof the computation methods and is anerror in analysis. The “middle effect” isnot the loss of lift in the center area ofthe wing, it’s the unanticipated loss oflift in the center area of the wing.

Horten

The Hortens, in an effort to coordinatestalling behavior and center of gravitywith other planform parameters,performed the necessary mathematicalcomputations, but always found errorsin their results. The aircraft did notbehave exactly as predicted becausethe center of pressure was not at thelocation predicted. The Hortensbelieved the problem to be related tothe intersection of the two quarterchord lines at the centerline, andenvisioned colliding vortices. Theyconstructed “bat tails” which substan-tially increased the root chord. Theirintent in using the bat tail was toreorient the quarter chord lines of thetwo wings and eliminate the collidingvortices. On the H IV, the quarterchord lines meet at right angles to thecenterline, while on the H VI thequarter chord lines actually bendbackward. Despite these changes to thequarter chord line, the “middle effect”remained. Al Bowers has suggestedthat the Hortens might have realizedthey were looking in the wrongdirection had they actually flown theirParabola design.

Despite their problems getting ahandle on the “middle effect,” theHorten twist distribution has thepotential to reduce induced drag andallow turns to be accomplished with-out adverse yaw. But aircraft willoperate as Dr. Horten envisioned onlywhen all of the design parameters areutilized: moderate sweep angle, largetaper ratio, carefully chosen airfoils(pitching moment), strong nonlineartwist distribution, “bell-shaped” spanload (lift distribution), and outboardailerons of defined size and configura-tion.

The Horten twist distribution is suchthat the wing twist is concentratedover the outer portion of the wing, inthe area where the sweep generatedupwash is greatest. Computing the

Page 5October 2003

twist distribution is a rather compli-cated affair, and we’ve been so farunable to obtain formulae of use tomodelers. Mathematically inclinedreaders may be interested in ReinholdStadler’s paper, “Solutions for the Bell-Shaped Lift Distribution.”

Culver

Unfortunately, Irv Culver did notwrite a comprehensive treatise on histwist formula. Rather, his descriptionof its use is sparse, and its derivationnot explained in any detail. Still, it ispossible to understand the generalthoughts behind Culver’s paradigm.

Although Culver did not specificallymention the “middle effect,” he didrealize that lift of a swept wing isdepressed in the area of the root. Tocompensate, some amount of up trimis required of the outboard elevons,depressing the lift generated by thatarea of the wing as well. Performanceis substantially reduced as a result. InCulver’s view, the ideal is to make thecenter portion of the wing producemore lift and thereby allow the wingtips to create more lift. At the designcoefficient of lift, the lift distribution isnear elliptical.

Another digression... The most simple

method of creating a twistedwing is to use a single foamcore and root and tiptemplates. Twist is thenimparted by setting the twotemplates at the appropriateangles relative to each other.Cutting with a tensioned hotwire always creates a wingwith straight leading andtrailing edges. This is quickand simple, but the angle oftwist does not changeconsistently across the semi-span. Rather, the anglechanges at a more rapid ratenear the root for wings withno taper, and near the wingtip if the wing is moderatelytapered. As Culver useswings with moderate taperin an effort to better achievean elliptical lift distribution,it is the latter situationwhich Culver wants toavoid.

In an effort to compensatefor the loss of lift in thecenter area of a swept backwing, Culver proposesplacing most of the twist inthe inboard 30% of the semi-span, say eight degrees.Three more degrees of twistare then imparted in theouter 70% of the semi-spanfor a total of eleven degrees.The increased angle of attackat the root increases the liftin that area. This allows theup trim of the elevons to bereduced, increasing the liftin that area as well. TheCulver twist thereforerequires constructing thesemi-span of a foam wing in

two parts rather than as a single panel.

As the sweep angle is increased, theCulver twist distribution calls for moretwist. As the Culver twist distributionis aimed at maintaining an elliptical liftdistribution at the design coefficient oflift, this is in keeping with the in-creased upwash which is anticipatedwill occur over the outer portion of thewing.

In flight, specially designed elevonsare used to trim for low coefficients oflift. As the aircraft approaches a stallattitude, the root will stall first whilethe wing tips remain well below their

R/C Soaring DigestPage 6

Page 7October 2003

R/C Soaring DigestPage 8

stall angle. This makes a fullstall across the entire span veryunlikely.

There are a few limitations tothe Culver twist distribution: itis accurate only for wings ofmodest sweep and taper, andthe recommended design liftcoefficient is for very highcompared with other method-ologies, particularly that of Dr.Walter Panknin. Since theCulver twist distribution isbased on maintaining a nearelliptical lift distribution,adverse yaw may be notice-able, particularly around thedesign coefficient of lift.

There are reports stating thatswept wing aircraft utilizingthe Culver twist distributionare both spin-proof andtumble-proof, and there is alsoat least one report stating theCulver twist distribution wasincorporated into the wings ofa number of Boeing commer-cial aircraft. These reports havenot been corroborated bysecondary sources, and itshould be noted that Boeingcommercial aircraft are ofconventional tailed configura-tion and utilize both rollspoilers and rudder to counteradverse yaw.

A six meter (236 inch) spanswept wing model using anapproximation of the Culvertwist distribution was con-structed in Germany in 1987.The Stromburg ’wing utilizedthe Eppler 220 for the outboardportion of the wing and theEppler 210 at the root, and hada sweep angle of 28.5 degrees.The twist angle at the root was11.5 degrees, going to zerodegrees at station .167 andremaining at zero degrees tothe wing tip. Elevons consistedof “Junkers flaps” from station.833 outboard. This modelperformed extremely well, andwas large enough to have amovie camera mounted at theCG and directed at the centersection. Films taken duringflight showed no air flowseparation at the root duringcruise, turning, high speedflight, or landing.

Panknin

Dr. Panknin derived his twist para-digm from a paper by Helmut Schenk.Using airfoil zero lift angles and

pitching moments, span and chords,sweep angle and static margin, a pitchstable tailless aircraft can be assured.The method relies heavily onMulthopp’s approximation of the lift

Page 9October 2003

distribution, but includes a correctionby D. Kuechemann so that it has goodaccuracy for sweep values for zero tobeyond 30 degrees. (Schenk states the“middle effect” still exists using thesecalculations.)

The Panknin methodology providesonly the total twist required forlongitudinal stability for a givenmonolithic wing with straight leadingand trailing edges and a predeter-mined static margin. The computedtwist values have been proven inpractice to be extremely accurate forsweep angles of up to 30 degrees,tapered or constant chord wing.

Like the Culver formulae, the Pankninmethod lends itself quite easily to bothcustom written computer programsand commercially available spread-sheet software. In fact, a scientificcalculator is sufficient when there areno time constraints. The defined twistangle can be used on a moderatelytapered wing using the foam coreconstruction method described previ-ously, with straight leading andtrailing edges from root to tip. Success-ful applications, however, includeplanforms with constant chord inwhich the twist begins at station 0.5,half the semispan, placing more of thetwist over the outboard portion of thewing.

All of Dr. Panknin’s designs, and ourown designs based on Dr. Panknin’sparadigm, incorporate winglets. Thesevertical surfaces assist in reducingoscillations in yaw in straight and levelflight and act to reduce adverse yaw atthe expense of some increase in drag.As we’ve stated in previous columns,thermal machines seem to climb betterwith winglets, racers track better witha single vertical fin mounted on thecenterline.

Conclusions

All three twist distributions have bothpositive and negative aspects.

The Horten twist distribution is basedon the work of Prandtl and others, andhas been supported by the more recentworks of R.T. Jones and Klein andViswanathan. The Horten paradigmhas the potential to reduce induceddrag and eliminate adverse yaw, but iscomputationally intensive and thetwist distribution itself must be used incombination with a number of addi-

tional planform attributes.

The Culver twist distribution iscentered on the elliptical lift distribu-tion. This is a conservative approachwhich provides relatively low dragand good efficiency within a confineddesign point, but may be prone toadverse yaw, particularly whenoperating at the design coefficient oflift.

The Panknin twist distribution hasproven itself over a nearly two decadeperiod to be an accurate determiner ofboth required wing twist and center ofgravity location. It has been used withgreat success by a very large numberof international designers. Its majorlimitation is that it calculates only thetwist required for pitch stability, but itcan be used as a fundamental methodof determining the approximateminimum twist required for a prelimi-nary design.

Figure 2A shows the elliptical liftdistribution for a conventional cross-tailed design as seen from behind. Thefuselage and vertical surface have beenneglected. Figure 2B shows thedownwash pattern this lift distributionproduces. Keep in mind the internalstructure of the wing is required tosupport both itself and a fuselage andtail structure. Additionally, the fuse-lage must be strong enough to supportitself and the mass and aerodynamicloads of the tail.

These factors, taken in combination,paint a picture of a relatively heavyaircraft with substantial surface andinterference drag. Additionally, thereis the surface and induced drag of theseparate relatively low aspect ratiohorizontal and vertical stabilizers. Inflight, large amounts of drag arecreated in an effort to make coordi-nated turns. Given this perspective, thepossibility of more efficient aerody-namics, as seen in Figure 2C, is obvi-ous.

While a specially tailored singlesurface wing may be necessary toachieve this goal, a well integrateddesign approach for tailless aircraft iscertainly very close, as demonstratedby the recent articles by Katherine Diazin Pilot Journal and Carl Hoffman inPopular Science. It is only a matter oftime before such design paradigmsand appropriate construction technolo-gies are available to modelers.

When designing a tailless planform,the type of twist distribution to beused should be one of the first deci-sions to be considered, and alwaysrelative to other aspects of the designsuch as prescribed task, design liftcoefficient, and planform. There are anumber of design “flowcharts” avail-able to assist the novice designer, andwe very much encourage readers toinvestigate their usefulness. Theinformation presented in this seriescan be used to augment these re-sources and assist in developingviable, and perhaps cutting edge,designs.__________

Ideas for future columns are alwayswelcome. RCSD readers can contact usby mail at P.O. Box 975, Olalla WA98359-0975, or by e-mail at<bsquared@appleisp.net>.

References, complete:

Allen, Michael. <http://pr.erau.edu/~allenm/wing.html>

Anderson, John D. Jr. Introduction toflight. McGraw-Hill, New York,1985.

—. Fundamentals of aerodynamics.McGraw-Hill, New York, 1984.

Bowers, Al. Correspondence within<http://www.nurflugel.com> e-mail list and private correspon-dence, 2000-2003.

—. The Horten H X series: ultra lightflying wing sailplanes. TWITTNewsletter, Andy Kecskes, editor,No. 148 October 1998, No. 149November 1998, No. 150 December1998. TWITT, El Cajon CA.

—. Manned flight - past, present,future. TWITT Newsletter, AndyKecskes, editor, No. 190 April 2002.TWITT, El Cajon CA.

Carmichael, Bruce. Personal aircraftdrag reduction. Self published, SanClemente California USA, 1995.

Coffey, Aaron. Culver twist distribu-tion spreadsheets. <http://www.b2streamlines.com/Culver.html>

Culver, Irv. Tailless -flying wings.TWITT Newsletter, Andy Kecskes,editor, No. 201 March 2003.TWITT, El Cajon CA. (Reprint ofarticle originally published in No.4, September/October 1986.)

de Piolenc, F. Marc. Flying wingdesign flowchart. TWITT Newslet-ter, F. Marc de Piolenc, editor, No.2 July 1986. TWITT, El Cajon CA.

R/C Soaring DigestPage 10

Diaz, Katherine. The call of the wild.Pilot Journal, May/June 2003, pp.78-87. Werner Publishing Corpora-tion, Los Angeles.

Dommasch, Daniel O., Sydney S.Sherby and Thomas F. Connolly.Airplane aerodynamics. PutnamPublishing Corporation, NewYork, 1951.

Donlan, Charles J., compiler. Aninterim report on the stability andcontrol of tailless airplanes. NACAReport No 796, 1944.

Eppler, Richard. Airfoil design anddata. Springer Verlag, New York,1990.

Ewald, Bernd. Will we have a Hortenflying wing in the air again? VGCNews No. 104, Winter 2000.Vintage Gliding Club, SomersetGreat Britain

Faye, Robert, Robert Laprete andMichael Winter. Blended wingletsfor improved airplane perfor-mance. AERO 17, pp. 16-31.Available at <http://www.boeing.com/commercial/aeromagazine/aero_17/winglets.pdf>

Fonteneau, Glyn. Panknin twistdistribution spreadsheet. <http://www.b2streamlines.com/Panknin.html>

Galè, Ferdinando. Tailless tail.B2Streamlines, Olalla WashingtonUSA, 1991.

Harrison, Joa. Panknin twist distribu-tion spreadsheet. <http://www.b2streamlines.com/Panknin.html>

Hoerner, Dr.-Ing. S.F. and H.V. Borst.Fluid-dynamic lift. Hoerner fluiddynamics, Vancouver WashingtonUSA, 1985.

Hoffman, Carl. The shape of wings tocome. Popular Science, October2003 and <http://www.popsci.com/popsci/avia-tion/article/0,12543,483523,00.html>

Horten, Dr. Reimar. Lift distributionon flying wing aircraft. Soaring,June 1981, pp. 40-42.

Hurt, H.H. Jr. Aerodynamics for navalaviators. Published as NAVWEPS00-80T-80 by the U.S. Navy, 1965.

Jones, Bradley. Elements of PracticalAerodynamics, third edition. JohnWiley & Sons, New York, 1942.

Jones, Robert T. Notes on the stabilityand control of tailless airplanes.NACA Technical Note No. 837,1941.

_. The spanwise distribution of lift forminimum induced drag of wingshaving a given lift and a givenbending moment, NACA TN 2249,1950.

—. Minimizing induced drag. Soaring,Oct 1979, pp. 26-29.

—. Wing theory. Princeton UniversityPress, Princeton NJ USA, 1990.

Kermode, A.C. Mechanics of flight.Pitman, London, 1980.

Klein, Armin and Sathy P.Viswanathan. Approximatesolution for minimum induceddrag of wings with given structuralweight. Journal of Aircraft, Feb1975, pp. 124-126.

Kuechemann, D. A simple method forcalculating the span and chordwiseloading on straight and sweptwings of any given aspect ratio atsubsonic speeds. R.A.E. Reportsand Memoranda Nr. 2935, August1952.

Lennon, A.G. “Andy.” R/C modelairplane design. MotorbooksInternational, Osceola WisconsinUSA, 1986.

Kirschbaum, Nathan. On-the-boarddesign progression. AircraftDesign Education Newsletter,W.H. Mason, editor, Vol. 2, No. 1,December 1, 1991. Blacksburg VA.

Masters, Norm. Correspondencewithin <http://www.nurflugel.com> e-mail list,2000-2003.

Maughmer, Mark D. The design ofwinglets for high-performancesailplanes. AIAA 2001-2406,Washington D.C., 2001. <http://www.mandhsoaring.com/articles/Winglet_Design.pdf>

—. About winglets. Soaring, June 2002,and <http://www.mandhsoaring.com/articles/WL-Soaring.pdf> (133K)

— and Peter J. Kunz. Sailplane wingletdesign. The Pennsylvania StateUniversity, University Park.Presented at the XXV OSTIVCongress, Saint Auban, France.<http://www.mandhsoaring.com/articles/ostiv97.pdf>

—, Timothy S. Swan, and Steve M.Willits. The design and testing of awinglet airfoil for low-speedaircraft. AIAA 2001-2478, Wash-ington D.C., 2001. <http://www.mandhsoaring.com/articles/Winglet_Testing.pdf>

McCormick, Barnes W. Aerodynamics,aeronautics, and flight mechanics.John Wiley and Sons, New York,1979.

Morris, S. J. Integrated aerodynamicsand control system design fortailless aircraft. AIAA-92-4604,Washington D.C., 1992.

Multhopp, Hans. Die berechnung derAuftriebsverteilung vonTragflügeln. 1938.

Munk, M. The minimum induced dragof airfoils, NACA Report 121, 1921.

Nickel, Karl, and Michael Wohlfahrt.Tailless aircraft in theory andpractice. American Institute ofAerodynamics and Astronautics,Washington D.C., 1994.

Nurflugel e-mail list. Correspondencefrom multiple authors regardingelliptical and bell-shaped liftdistributions, June 18 through June26, 2003.

Panknin, Dr. Walter. Flying rainbows.Proceedings MARCS Symposium1989. Al Scidmore, editor. MadisonArea Radio Control Society,Madison WI, 1990.

Perkins, Courtland D. and Robert E.Hage. Airplane performance,stability and control. John Wiley &Sons, New York, 1949.

Prandtl, L. Applications of modernhydrodynamics to aeronautics.NACA Report 116, 1921.

—. Uber Tragflügel des kleinsteninduzierten Widerstandes. ZeitsFlugeltechnik undMotorluftschiffahrt, Vol. 24, pp.305-306, Nov 1933.

Raymer, Daniel P. Aircraft design: aconceptual approach. AIAAEducation Series, Washington, DC,1992.

Schenk, Helmut. Laengsmomenten-rechnung beim Nurfluegel-Modell.Self published, Pforzheim, Ger-many, publication date unknown(acquired 1996).

Schönherr, Prof. M. Das Stromburg-Prinzip — Ein versuch, 7Nurflügelprobleme zu lösen.Faszination Nurflügel, Hans-Jürgen Unverferth, editor. Verlagfür Technik and Handwerk GmbH,Baden-Baden Germany, 1989.

Schrenk, Oskar. A simple approxima-tion method for obtaining thespanwise lift distribution. NACATechnical Memorandum No. 948,1940.

Page 11October 2003

Shevell, Richard S. Fundamentals offlight. Prentice-Hall, EnglewoodCliffs NJ USA, 1983.

Simons, Martin. Model aircraft aerody-namics. Argus Books, HemelHempstead Great Britain, 1994.

—. Airflow. AE Press, Melbourne,1984.

Smith, H.C. “Skip.” The illustratedguide to aerodynamics, secondedition. TAB Books, Blue RidgeSummit Pennsylvania USA, 1992.

Stackhouse, Don. Correspondencewithin <http://www.nurflugel.com> e-mail list,2000-2003

Stadler, Reinhold. Solutions for thebell-shaped lift distribution.Self-published, 1996. <http://www.nurflugel.com/Nurflugel/Papers/h_ca_01e.pdf>

Sutherland, Alasdair. Basic aeronauticsfor modellers. Traplet Publications,Worcestershire UK, 1995.

Thies, Werner. Eppler-Profile, MTB 1.Verlag für Technik and HandwerkGmbH, Baden-Baden Germany,1983.

Tucker, Chuck, J. J. Quinn, BarnabyWainfan and Walter Boyne. Flyingwings. Flight Journal, October2003, pp. 24-44. Air Age Inc.,Ridgefield CT.

Wegener, Peter P. What makes air-planes fly? Springer Verlag, NewYork, 1991.

The White Sheet, Spring 1986, No. 36.Sean Walbank, editor. White SheetRadio Flying Club, DorsetSomerset Great Britain.

Wills, C. Horten - the truth. VGCNews, (Part 1) No. 105, Spring 2002pp. 40-42, and (Part 2) No. 106,Summer 2002, pp. 36-38. VintageGliding Club, Somerset GreatBritain.

Wooldridge, E.T. Winged wonders, thestory of flying wings. SmithsonianInstitution Press, Washington D.C,1988.

n

R/C Soaring Digest556 Funston Drive

Santa Rosa, CA 95407

e-mail: RCSDigest@aol.comhttp://www.b2streamlines.com/RCSD.html

A MONTHLY LOOK INTO THE WORLD OF SAILPLANE ENTHUSIASTS EVERYWHERE

R/C Soaring Digest Subscription Form

R/C Soaring Digest (RCSD) is a reader-written monthly publication for theR/C sailplane enthusiast. Published since 1984, RCSD is dedicated to thesharing of technical and educational information related to R/C soaring.

RCSD encourages new ideas, thereby creating a forum where modelers canexchange concepts and share findings, from theory to practical application.Article topics include design and construction of RC sailplanes, kit reviews,airfoil data, sources of hard to find items, and discussions of various flyingtechniques, to name just a few. Photos and illustrations are always inabundance.

There are RCSD subscribers worldwide.

USA: $30 First Class (CA res., please add $2.25 tax.)Canada & Mexico: $30 AirEurope/U.K.: $45 AirAsia/Africa/Pacific/Middle East: $52 Air

Check or Money Order, only, please. U.S. funds.

Name_________________________________________Address___________________________________________________________________________________________________________________________________

SPRIN G TIM

E!

ZIKA

R/C Soaring DigestPage 12

Icall my husband’s workshop the“balsa dungeon.” Early on, I was a

little pissed because he put so muchwork into building the benches andputting up shelves and lights andelectrical outlets, but I soon foundmyself down there snooping aroundand finding all kinds of cool suppliesand tools, not to mention what anefficient work space for those tasksyou want to protect your carpet from.

I am a crafter, thread bender, artist. I’malways trying out new techniques. I’malso the yardman, handyman,plumber, painter, carpenter, and maidat our house. The treasure in the balsadungeon has made my life easier.Some of the items hidden down therewere so cool or so useful to me I had tohave my own - like the heat gun. Iwore out three of Dave’s heat guns sohe finally bought me my own. I alsohad to have my own Dremel tool andbalsa strip cutter, mini files, smallplane, drill and bits, and miniaturepliers set. Sharing can be over rated.

I’ll list the tools and supplies I’ve usedover the years and what I used themfor, but feel I have to tell one littlestory about how my husband and thetools in the balsa dungeon saved mysanity.

I had broken a bone in my foot andhad a walking cast. It wasn’t too bad, Icould get around and even drive mystandard shift car. I was supposed towear the cast for six weeks. Well, afterfive weeks and five days I wentcompletely nuts. I couldn’t stand thecast one minute longer. It was itchyand hot and uncomfortable and thecast was making sleep almost impos-sible. I was TOTALLY freaking outand had to have the cast off IMMEDI-ATELY. After calling the doctor andgetting permission, Dave sawed mycast off with the Dremel tool andprevented my head from exploding.

Specialized adhesives:

• Tan carpenter’s glue: fix furni-ture, fix broken wooden knittingneedles (I break a lot of knittingneedles), bind handmade books.

• Goop®: fix flapping soled sneakers,seal the base to the dome of hand-made snow globe.

• CA: fix deeply torn fingernails, alsokeeps cuts “too deep for a BandAid” closed, repairs broken potteryand dishes - and all in about 30seconds.

• Epoxy (and epoxy fillers likemilled fiberglass): fix handmadewooden knitting swift for windingskeins of yarn (basically had to fill aworn wooden threads and re-boreso the swift could be clamped to atable). This repair saved andbeautifully hand crafted woodentool that would have been expen-sive to replace. Repair antique chairthat had chunks of wood missing,preventing broken parts frominterlocking and supporting theseat. Used epoxy and micro bal-loons for “creating” missing wood.

Drill – I probably drilled a thousandholes in the house and in projects overthe last 20 years.

Soldering tools - fix broken jewelry,make new original jewelry, fix thewiring on the clothes dryer.

Small saws, files, X-acto®knives, pliers, large and smallscrewdrivers - cut and shape small,

delicate items, cut out stencils, emer-gency orthodontia repairs. Excellentfor working with polymer clay beforeand after curing.

Specialized tape - wrap packages,bind or repair books, seal gaps be-tween the window frame and airconditioners. The special Mylar™ tapethat the flyers use to hinge the aileronsor flaps or whatever those controlpanels are on the wings is also greatfor hinging anything. It’s one of myfavorites.

Heat-shrink tubing - fix circularknitting needles, encapsulate solderedor glued stuff (like knitting needles orwashing machine wiring harness).

Small clamps (holding items whileglue sets up) - convenient for fixingframes, book bindings, all the obvious“hold this” stuff.

Dowels - make knitting needles,curtain rods, quilt hangers, furniturerepair, plugs for when you goof and“measure once and drill twice.”

Heat gun - dry paint, remove paint,remove labels from boxes and enve-lopes so you can reuse them, removestamps that didn’t get postmarked forreuse. Shrink plastic wrap for giftbaskets. For those “in the knowcrafters” shrink Shrinky Dink®

Hidden Treasure in the Balsa Dungeon

by Paula Garwood

Attention ladies, there is valuable stuff in your RC flyer’s workshop.

Page 13October 2003

artifacts. Melt embossing powder forrubber stamping, dry the ink whenrubber stamping.

Covering iron - fuse covering forbook/journal making. Use with fusibleweb to repair wallpaper -anything youmight want to use your iron for on avertical or small surface or somethingyou don’t want to use your regulariron for since you use it on yourclothes. Be careful though, it doesn’thave the sophisticated temperaturecontrol that your “domestic” iron does.

Dremel® rotary tool - buff stuff,sand small places on furniture or yourwooden creations, remove orthopediccasts (maybe to get your doctor’spermission).

Balsa Strip Cutter - for cuttingmasking tape into 1/4" strips forquilting guides.

Scroll Saw - easily cut wood (dowelsto 2x4s) for craft projects or homerepairs.

Mini Plane - shape and rough finishpolymer clay projects to save on thesanding.

Sand Paper - sanding anything oreverything.

I have become such a frequent visitorto the balsa dungeon, that I started tonag a little about more “bench space”for myself. I did manage to get Dave to“light up” my side of the basement sothat I now have my “own” well-

lighted bench in the laundry dungeon.Like I said before, sharing is overrated.

Now ladies, don’t think for a minutethat this is a one-way street. I showedDave the joys of using a hot-melt gluegun, and I keep him in waxed paperand paper towels. I say support TheOld Man so that he keeps buying glueand dowels and sandpaper and thestuff we need.

n

R/C Soaring DigestPage 14

“The Sloper’s Resource”

Greg’s Brian McLean Extreme crusing overLake Michigan. Photo: Mirko Bodul.By Greg Smith of slopeflyer.com

greg@slopeflyer.comhttp://www.slopeflyer.com

Dave Garwood recently sent me anote from a guy who is just

learning to fly R/C and how he foundhappiness at the slope after the frus-trating experiences he had trying tolearn to fly with electric powered R/Cplanes. It reminded me of my experi-ences learning to ski in the Midwest.FYI, I learned to fly R/C at the slope inthe early ‘80s so I can only share byassociation the frustrations of learningto fly any other way!

Here in the Midwest we obviously getsnow, and we have hills, so it seemsthat learning to ski should be a no-brainer. Problem is the hills are allsmall, 300 vertical or less, and justwhen you start getting the hang of it,you are at the bottom! Then, wait inline 10-15 minutes to get back to thetop, forget what you just learned anddo it all over again, falling most of theway. Didn’t help that the snow wasreally more like ice.

Out West, the scenario is totallydifferent. Thousands of vertical feetmean you get a lot more time to ski onyour way down and as you get up

from each fall you find yourself beingable to go longer between falls becauseyou can get at it again right away. Ilearned more about skiing in two daysat Heavenly Valley in California thanin 3 years of face plants in the Mid-west.

And so it goes with R/C flying.Sloping is like that beautiful mountainat Heavenly Valley; you get a lot ofairtime without all the peripheraldistractions like charging the motorbattery or gassing up the plane just tobe in the air for 5 minutes. Then, youhave to start all over. In the 20 minutesof prep time between flights you canforget a lot! At the slope picking up theEPP wing and tossing it back out in thelift is like getting up on the ski slopeafter a fall with 3 more miles of runleft. You’ve got a long time to learn.You can learn more at the slope over aweekend than in a whole season at thelocal power field.

Sure, people do learn to ski in theMidwest, it happens all the time. Justlike people learn to fly R/C at the localpark or at the power field. However Ican’t help but think that the joy offlight is somewhat diminished by thefrustration that accompanies all thehassles that go with learning to fly in

an environment where the reward forall your hard work and prep time is a 3to 5 minute flight and, likely as not, aplane you have to repair after thatshort period of time. It will alsoprobably take more time than the 10-minute ride to the top of the ski hill torepair that plane and have another go.

BTW, I have a nominee for a great firstslope plane: the Weasel from RichterR/C at www.flyweasel.com. It wasextensively reviewed, and constructionnotes were reported, in RCSD, a coupleof months back so you may havealready heard of it. I have been flyingone for a couple of months now. Onecool thing about the Weasel is it is agreat advanced pilot’s plane too. Justmove the CG back and it goes fromstable, predictable beginners plane to asuper aerobatic performer. I have hadit in winds as light as 4 and as heavy as25. I even had a chance the DS it on arecent trip to South Dakota! It alwaysworks well. It is also one of the easiestplanes to fly inverted that I own. It letsme fly when I otherwise could not andat slopes that are not suitable for anyother plane. All this in a 36-inch spanglider that stows anywhere! Cool!

Page 15October 2003

Me and my Weasel at the Big Bay slope inMlwaukee. Photo: Mirko Bodul.

This month’s links:

Richter R/C –http://www.flyweasel.com

McLean Extreme –http://www.mccomposites.com

The wind finally started to pick uphere in Milwaukee and we have had acouple of good days at the sloperecently. Besides flying the Weaselregularly, I have had some great flightswith my molded McLean Extreme.Brian has a winner with this one! Thenew Extreme would definitely be atthe top of my list if anyone ever gaveme the dreadful ultimatum, “You canonly have one slope plane for the restof your life; which one is it going tobe?”

Time to wrap it up. Until next time,here is a little thought for you courtesyof the New York Slope Dogs: Talk’sCheap, Let’s Fly! n

GONE SOARIN’Zika

ZIKA

R/C Soaring DigestPage 16

GORDY’S TRAVELS

Home in- On the Range... Check!

We often have heard about howimportant doing a simple range checkis to check up on our transmitter’sconnection to our sailplane’s receiverand, pretty much, we all know how todo it... But that was the good old days.

I recently had one of those months,definitely a trip I hope I never experi-ence again. Two brand new moldedplanes destroyed after just a fewflights.

I had heard of planes having receptionproblems due to high carbon contentin their fuselages but most of thereports were from Europe. Now Iguess that makes sense, because Euro’stend to only fly molded planes withmostly carbon fuselages and, untilrecently, we flew mostly Kevlarfuselages.

It seems the worst signal ‘blanking’problems occur in planes which use acoarse weave, sort of like burlap, crosscarbon/Kevlar weave. The materialseems to create a ‘choke’ which killsthe transmitter’s signal in the receiver’santenna, in effect cutting its length.

And that means lost range.

I went to the web site focused on themolded planes I had, and read thecomments and articles about how itwas important to route the antennaoutside the fuselage... But since “I”knew so much about the hobby, Ididn’t really read the articles in detail.

And I didn’t believe their advice; moreimportantly I didn’t do a range test...Actually I never have, not once in allmy time in the hobby.

So, I lost the first model almost on thefirst day of flying. I was gettingglitched but the plane seemed to beflying okay. Until I got a little furtheraway and it went in hard.

I remembered something about havingthe antenna outside the fuse so, on thenext model, I ran it outside the canopyand along the fuselage tail boom – butagain, no range check.

I flew this one a few times and it hadsome problems, but it seemed to fly farout okay. Then finally it went in.Fortunately, it landed in a hay fieldand sustained pretty minor damage.

That night I went back to the web siteand read the notes more carefully. Thefirst thing I found there was this note:

“ Don’t run the antenna out thecanopy. It’s almost as bad as run-ning it in the fuse!”

Dup! After reading more, I found thatthey had done lots of real worldtesting, finding alternative routings forthe antenna. One key factor in theirsuccess was to get the antenna not onlyoutside the fuselage but ‘away’ fromthe fuselage.

I also heard from some other guys herewho had run into the problems withrange with the same model. Now don’teven think it’s just this particularmodel, because I have since heard ofother models using the same weavematerial. Some guys in Denver had thesame plane but the ‘light’ versionwhich mainly had a lighter wing withonly the area forward of the spar made

of carbon. They had found that theycould use the 9th pin of their 9 pin Dconnector to route the antenna intoeach side of the wing. They also foundit didn’t work on the full carbon lay-upwing that I had.

I was pretty fed up with guesses, so Idecided to figure out my own ‘rangetest’. I own a Picalario Talking Altim-eter which has a glitch warningfeature. That means if the servos get tojiggling, a lady announces, “Attention,Attention, Attention.” This meant Ihad a tool to specifically gauge rangeloss during a ‘standard’ range test.

I went to the park, set up the plane inmy Super-Stand, and sat down to thinkabout the best way to perform therange test. I decided that I needed tofind a benchmark to start from - a setup that would provide me with anantenna down, measured distance.

I figured that if I took the receiver outof the plane, and then plugged in 6servos and battery, with the antennahanging free of any obstruction, thatshould be the cleanest possible set upfor my distance range test.

With the Picalario plugged, I paced off350’ before I got an “Attention.” Wow!I had tried a test the way I had beenflying it and that produced about 35’.

The web site mentioned the best theyhad found was to run the antenna inthe fuse, exiting the fuselage top justbehind the trailing edge of the wing,adding at least the amount of wire thatwas inside to the wire extendedoutside. Then, to run the wire up to thetop of the vertical stabilizer, letting therest trail behind. Uck! But better thanlosing the plane, so I decided to addabout 20” instead of just the 10” in thefuse, then to trim back till it affected

Gordy StahlLouisville, KentuckyGordySoar@aol.com

Page 17October 2003

the optimum range.

Okay, so with all of the on board stuffhooked back up, the RX in the plane,and the antenna routed in the fuse tojust behind the wing to exit, extendedthat 20”, I began my tests.

Each time I got the optimum, I wouldtrim off an inch. I didn’t want a bunchof wire flopping around the back ofmy plane. Sure enough, I got to wherethe antenna was 2” longer than the

tiptop of the vertical and I still had fullrange.

Just to double check, having it taped tothe outside of the tail boom wouldhave a negative effect on range, I tapedit along the boom, with the excessdangling. Almost all that range waslost.

The wire’s total length ended up beingalmost exactly the same amount thatwas inside the fuselage.

It’s not the good ole’ days anymore,things have changed, definitely for thebetter. Those fuselages are super stiff,light and durable, but they can causesome radio range problems if notunderstood and measures taken toinsure clean reception.

If you have one of the new breedmolded planes, take the time to set upwith the RX and servos outside thefuselage. If you don’t own a Picalario,just have someone stand by yourmodel to signal you when they see aproblem. Move only one surfaceconsistently, and then start countingyour paces to find your system’soptimum potential range. Loadeverything back inside, including theantenna wire as you have in the past.Then do the test again to see if you

have been actually enjoying the bestpossible range.

Your TX antenna (top mount) shouldbe completely collapsed, which willleave only the first segment extended.‘Inny’ mount antennas, which collapsecompletely into the TX, leave onesegment up, about 6”.

The idea is to find out what the bestpossible range is, then to try to reachthat with your antenna location.

Things like carbon or steel pushrods,powerful servos are also consider-ations for decreasing range. UsingTorrodial Rings (iron rings), electronicchokes, etc., can cut down on jigglescaused by signal feedback from longservo leads and power wing servos;but jiggles can also be an indicator thatit might be wise to get more seriousabout antenna placement.

PCM radios ‘mask’ interference andsignal loss, creating a sort of ignoranceis bliss situation for some modelers. Doyour range testing with a non-PCMsystem. Then, once you have deter-mined your best receiver antennalocation, reinstall your PCM.

SCHEDULE OF SPECIALEVENTS

November 29-30, 2003Tangerine Soaring Orlando, FL Championshipswww.orlandobuzzards.org

Please send in yourscheduled 2004 events

as they become available!

ZIKA

GONE SOARIN’

Our sailplanes are expensive butmostly they are hard to replace; it’sworth it to take some extreme precau-tions to protect them. Give it a try andI think you’ll be less likely to ‘stumble’with your next soaring adventure.

Oh yeah, I said, “Two new moldedsailplanes destroyed.” The second oneworked so well that I flew the batteryout. I guess I still have a lot to learn.

Coming down the road is a review ona new FM, Channel Synthesized,Digital Signal Processing, Micro 8channel Receiver, which allows you topre-scan the frequency you are set onto see if someone else is on thatfrequency. It will also allow you tomaintain control of your model ifsomeone else turns a TX on yourfrequency!

See you next trip!

n

R/C Soaring DigestPage 18

Please read no furtherunless you are interested

in AMA Politics.

By Dr. Sandy Frank- AMA Life Member #L-69

105 N. BrazosWeatherford, TX 76086-3207Phone/Fax: (817) 599-7131

E-mail: sfrank69@airmail.net

NOW it is Executive Council (AMABoard of Directors) election time

in the AMA District VIII region.

Each adult AMA member (almost19,000) who reside within the states of:Texas, New Mexico, Oklahoma,Arkansas and Louisiana will be sent aballot (to save outgoing postage thisballot is enclosed within their 2004membership renewal paperwork).

It is NOT required that you submityour 2004 membership renewal at thesame time as your ballot. In fact yourrenewal and your vote MUST be sentto separate locations to be properlyprocessed (AND COUNTED).

Each year literally thousands of AMAelection ballots are improperly sent tothe AMA Headquarters enclosedwithin their membership renewal.

(Some have told me that they thoughtthat they were saving AMA postage bysending these together by enclosingtheir ballot within their membershiprenewal paperwork.)

This is NOT at all THE CASE as YOURVOTE MUST be sent to a separateaddress where the auditors indepen-dently tally the votes. So PLEASE usethe postage paid postcard to cast yourballot - just mark it and drop in intothe mail. (It is pre-addressed andpostage paid and will get to theauditors.)

IF YOU ENCLOSE YOUR BALLOTWITHIN YOUR RENEWAL PAPER-WORK AND SEND IT TO AMAHEADQUARTERS IN MUNCIE,INDIANA IT WILL NOT BECOUNTED AND WILL BE DE-STROYED.

The 2004-2006 term of office for theAMA Board of Directors (ExecutiveCouncil) will set the course whichAMA takes into the 21st Century.

Your input via your vote is needed andimportant!

Elsewhere you will be seeing thepolitical rhetoric and campaignpromises of all the candidates in thiselection!

Please read it to help you choose whoto vote for... Or if you choose to, pleasecontact the candidates directly andpersonally to ask any questions whichyou may have of them and theircandidacy.

(I gladly publish my contact informa-tion and would be HAPPY to discussthis election with anyone at anytime!)

Historically only 10% to 12% of theeligible membership votes in theseelections.

Many just do not BOTHER to VOTE!

So please vote! Your vote is neededand important!

It is by YOUR vote that you canexpress how much you really careabout your AMA organization, and itsmission and its goals and its objectives.

Please read no further unless you areinterested in AMA Politics...

Please read no further unless you areinterested in AMA Politics...

Please read no further unless you areinterested in AMA Politics...

HERE is where I stand and WHAT Istand for!!!

And please consider the following...

sfrank69@airmail.net wrote:

Hello,

I am Dr. Sandy Frank of Weatherford,TX. I am seeking your vote for re-election as your AMA District VIIIrepresentative to the AMA Board ofDirectors. In that capacity, I willcontinue to insure that your thoughts,concerns, and issues are broughtforward for consideration by the entireAMA Executive Council. The 2004-2006 term of office will continue tosteer the course for AMA into the 21stCentury.

Please vote.

I have been an aeromodeler since myearliest recollections, an AMA membersince 1957, and have built, flown,competed with and enjoyed, all typesof C/L, F/F and R/C model aircraft.As a child, I was taught about model-ing and over the following 39 years Ihave learned and experienced thepersonal fulfillment of AMA volunteerwork at the local, regional and nationalvolunteer levels.

As a means by which to better servethe AMA members and all modelers ofDistrict VIII, in 1999 I conceived,organized, and produced the firstSouthwestern Aeromodeling Confer-ence in Arlington, TX. (SWAC 2003 -Oct. 3rd - 4th) All profits will onceagain go to AMA projects and initia-tives (within the 5 state region of AMADistrict VIII).

I have been successful in my personalcareer as a Licensed Psychologist(Ph.D.) and have owned and operateda private practice, but am now semiretired. My record on Council for thepast six years is solid proof of myextensive leadership, management,and representational skills. I can, andwill, continue to devote the time,energy, and effort required to repre-sent “YOU” well to the AMA Board ofDirectors.

Your vote is needed and important!

I will support no dues increases orAMA instigated lawsuits. I willcontinue to place local modelingsupport (especially flying site assis-tance) as AMA’s highest priority, andwork to even further open communica-tions between the AMA and all of itsmembers.

Your vote for me will be a vote forprogressive and dynamic representa-tion of each and every member ofDistrict VIII, and sincerely appreciated.I am available 24 X 7 X 365 to assistyou!

n

Page 19October 2003

T.W.I.T.T.(The Wing Is The Thing)

T.W.I.T.T. is a non-profit organization whosemembership seeks to promote the researchand development of flying wings and othertailless aircraft by providing a forum for theexchange of ideas and experiences on aninternational basis. T.W.I.T.T. is affiliatedwith The Hunsaker Foundation which isdedicated to furthering education andresearch in a variety of disciplines. Fullinformation package including one back issueof newsletter is $2.50 US ($3.00 foreign).Subscription rates are $20.00 (US) or $30.00(Foreign) per year for 12 issues.

T.W.I.T.T., P.O. Box 20430El Cajon, CA 92021

www.twitt.org

The Eastern Soaring League (ESL) is a confederation of Soaring Clubs, spread across the Mid-Atlantic and New England areas, committed to high-quality R/C Soaring competition.AMA Sanctioned soaring competitions provide the basis for ESL contests. Further guidelines arecontinuously developed and applied in a drive to achieve the highest quality competitionspossible.Typical ESL competition weekends feature 7, or more, rounds per day with separate contests onSaturday and Sunday. Year-end champions are crowned in a two-class pilot skill structureproviding competition opportunities for a large spectrum of pilots. Additionally, the ESL offers aRookie Of The Year program for introduction of new flyers to the joys of R/C Soaring competition.Continuing with the 20+ year tradition of extremely enjoyable flying, the 1999 season will include14 weekend competitions in HLG, 2-M, F3J, F3B, and Unlimited soaring events. Come on out andtry the ESL, make some new friends and enjoy camaraderie that can only be found amongst R/CSoaring enthusiasts!

ESL Web Site: http://www.e-s-l.org

The League of Silent Flight (LSF) is an internationalfraternity of RC Soaring pilots who have earned theright to become members by achieving specificgoals in soaring flight. There are no dues. Once youqualify for membership you are in for life.The LSF program consists of five “AchievementLevels”. These levels contain specific soaring tasksto be completed prior to advancement to the nextlevel.Send for your aspirant form, today:

League of Silent Flightc/o AMA

P.O. Box 3028Muncie, IN 47302-1028 U.S.A.

http://www.silentflight.org

SailplaneHomebuilders

Association (SHA)

A Division of the SoaringSociety of America

The purpose of theSailplane HomebuildersAssociation is to stimulate interest in full-sizesailplane design and construction byhomebuilders. To establish classes,standards, categories, where applicable. Todesiminate information relating to constructiontechniques, materials, theory and relatedtopics. To give recognition for noteworthydesigns and accomplishments.SHA publishes the bi-monthly SailplaneBuilder newsletter. Membership cost: $15U.S. Student (3rd Class Mail), $21 U.S. RegularMembership (3rd Class Mail), $30 U.S. RegularMembership (1st Class Mail), $29 for All OtherCountries (Surface Mail).Sailplane Homebuilders Association

Dan Armstrong, Sec./Treas.21100 Angel Street

Tehachapi, CA 93561 U.S.A.

Classified Advertising PolicyClassified ads are free of charge to subscribersprovided the ad is personal in nature and does notrefer to a business enterprise. Classified ads thatrefer to a business enterprise are charged $5.00/month and are limited to a maximum of 40 words.RCSD has neither the facilities or the staff to inves-tigate advertising claims. However, please notifyRCSD if any misrepresentation occurs. Personalads are run for one month and are then deletedautomatically. If you have items that might be hardto sell, you may run the ad for 2-3 months.

For Sale - Business

PARACHUTES: $12.50 (includes S&H U.S.A.)Send check or money order to Dale King, 1111Highridge Drive, Wylie, TX 75098; (972) 475-8093.

Summary of Low-Speed Airfoil Data - Volume 3 is reallytwo volumes in one book. Michael Selig and his studentscouldn’t complete the book on series 3 before series 4was well along, so decided to combine the two series ina single volume of 444 pages. This issue contains muchthat is new and interesting. The wind tunnel has beenimproved significantly and pitching moment measure-ment was added to its capability. 37 airfoils were tested.Many had multiple tests with flaps or turbulation ofvarious configurations. All now have the tested pitchingmoment data included. Vol 3 is available for $35. Ship-ping in the USA add $6 for the postage and packagingcosts. The international postal surcharge is $8 for surfacemail to anywhere, air mail to Europe $20, Asia/Africa$25, and the Pacific Rim $27. Volumes 1 (1995) and 2(1996) are also available, as are computer disks contain-ing the tabulated data from each test series. For moreinformation contact: SoarTech, Herk Stokely, 1504N. Horseshoe Circle, Virginia Beach, VA 23451 U.S.A.,phone (757) 428-8064, e-mail <herkstok@aol.com>.

Reference Material

BBS/Internet

Internet soaring mailing listserve linking hundreds ofsoaring pilots worldwide. Send msg. containing theword "subscribe" to soaring-request@airage.com. The"digestified" version that combines all msgs. each dayinto one msg. is recommended for dial-up users on theInternet, AOL, CIS, etc. Subscribe using soaring-digest-request@airage.com. Post msgs. tosoaring@airage.com. For more info., contact MichaelLachowski at mikel@airage.com.

Books by Martin Simons: "World's VintageSailplanes, 1908-45", "Slingsby Sailplanes","German Air Attaché", "Sailplanes bySchweizer". Send inquiries to: Raul Blacksten,P.O. Box 307, Maywood, CA 90270,<raulb@earthlink.net>. To view summary ofbook info.: http://home.earthlink.net/~raulb

There is a growing interest in scale soaring inthe U.S. We are dedicated to all aspects ofscale soaring. Scale soaring festivals andcompetitions all year. Source for informationon plans, kits, accessories and other peopleinterested in scale. For more information:

web site: www.soaringissa.org

InternationalScale SoaringAssociation

R/C Soaring DigestPage 20