Page 1April 2003

April, 2003Vol. 20, No. 4

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 Products 3 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 ................................................................................................... 2003 Eastern Workshop

4 "On The Wing..." ......................................................................Bill & Bunny KuhlmanFlying Wing Design & Analysis .............................................................................. Blackbird XC.3

9 "Gordy's Travels" ................................................................................. Gordy StahlSailplane Design .....................................................................................Balance Affects landings

10 "Have Sailplane Will Travel!" ..................................................................Tom NagelTravel Saga ...................................................................................................... The Stealth Sloper................................................................... A Travel Sailplane from "Have Sailplane Will Travel!"

13 Workshop Design .................................................................................. Lee Murray........................................................................................................ Visit to Fran LeClercq's Shop

14 "Tech Topics" ................................................................................... Dave RegisterTechnical Analysis & Design ...........................................................A Fiberglass Fuselage Repair

15 Flying Techniques .................................................................................... Bill Kuhl...................................................................................... Path to Improvement in Thermal Soaring

17 "Gordy's Travels" ................................................................................. Gordy StahlFlying Techniques ................................................................. Ten Tips That You Have Found Lift!

8 Cavazos Sailplane Design8 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

Events20 Eastern Workshop - MD9 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 3April 2003

TheSoaring

Site

Slope Flying

Jeff Fukushima at PSS Festival,Cajon Summit, California in

1999.

Jeff walks to the edge to launchhis F-18 Hornet, which he kitsand sells along with other slopejets and PSS warbirds at VortechModels.

Photography byDave Garwood, New York.

SCHEDULE OF SPECIALEVENTS

May 15-18, 2003Midwest Slope Challenge Wilson Lake, KSwww.alltel.net/~mwsc

May 24-25, 2003So. California PSS Festival Cajon Summit, CABrian Laird, Slope_Scale@compuserve.com<ourworld.compuserve.com/homepages/slope_scale>

June 6-8, 2003Spring Aero Tow Festival Visalia, CAChris Pratt, cmesoar@quik.comhttp://www.cvrcsoaring.com(559) 733-5188 (7-9pm)

June 13-15, 2003JR Aerotow Monticello, ILpdf file available on the RCSD main web page

June 20-22, 2003Eastern Workshop Ridgely, MDTom Blevins, tomblevins@gwi.net207-882-6396

July 19-26, 2003AMA/LSF NATS Muncie, IN

October 10-11, 2003Texas National Tournament (TNT) Dallas, TXwww.SLNT.org

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

Please send in yourscheduled 2003 events

as they become available!

Happy Flying!Judy Slates

Sailplane Builders2003 Eastern Workshop

We received an invitation from TomBlevins to the R/C community to joinSailplane builders and pilots for a Mid-summers Night Weekend of fun. Theregistration form for this event is alsoincluded in this issue of RCSD (backpage).

Friday, June 20th - Sunday, June 22ndRidgely Airpark

Ridgely MD on Maryland’s EasternShore

“This year’s workshop emphasis willbe on flying, sharing sailplane-build-ing experiences and techniques, andjust hanging out together. We willhave a few technical presenters and asmany kit-providers and builders as wecan muster, but there will be more timefor flying and talking with friends.Come with plans and bits and pieces ofwhat you’re working on, or a flyablefinished product: just let us know whatyou’re bringing.

“For more information on the SailplaneBuilders see:

www.sailplanehomebuilders.com/

Contact:Tom Blevins

tomblevins@gwi.net(207) 882-6396

178 Boothbay Rd.Edgecomb ME 04556

Workshop Program in-the-Works

“Steve Arndt, Eastern VP, will showand talk about the Carbon Dragon hebuilt, then demonstrate the Dragon’soutstanding performance. [Take-Offsare optional, Landings mandatory!]

“Leo Benetti, with Alisport(www.alisport.com), will talk about his12 meter Silent motorglider and thenew Silent II 13 meter. The Silentseries, with and without motors, areavailable in quick build kits providing

outstanding performance at a moder-ate price. Leo will also bring photosfrom his recent trip to the factory inCremella, Italy.

“John Marske, hopefully, will fly hissingle-wing Monarch for us andupdate on his latest design work.

“R/C Sailplanes - We are hoping tofind someone (or several!) to talk aboutR/C Sailplanes and demonstrate themwith flights at the Airpark.

“Jeff Snyder and his resident GliderCub will have their collection ofgliders to see and discuss. Schweizerspredominate but we might be sur-prised.

“Mark Maughmer PhD, Penn StateAerodynamicist, is expected to give usa variation of his talk “Aerodynamicsfor Dummies” and bring his guitar.

“Goetz “Pipa” Bramesfeld, PSU, willtalk to us about German glider devel-opments and hopefully show us thewing testing (destruction) video again.

“Dave Hudnut and Al McCarty willtalk to us about metal aircraft buildingtechniques and report on their build-ing progress.

“Tom Blevins will talk about Ad-vanced Composites construction, givea sample demonstration, and welcomequestions during the Workshop.

“Bring what you know. Bring whatyou have to show. Everyone hassomething to offer.”

Thanks for the invitation, Tom!

R/C Soaring DigestPage 4

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

Blackbird XC.3

As mentioned in a previous column, we’rehard at work on our third Blackbird XC.This will be the eighth Blackbird to comeoff our building board. As usual, we’veincorporated many modifications to theoriginal design besides the enlarged size.This column will describe all of the variouschanges to be incorporated in this rendi-tion and share some of the highlights of theconstruction process. The second install-ment will cover completion of constructionand test flying.

Our experience with Dave Jones’Blackbird planform goes back

nearly twenty years. We’ve alwaysfound it to be relatively easy to build,stable and maneuverable in flight, and,in spite of its total lack of exoticmaterials, capable of full power “pedalto the metal” winch launches whichend in thrilling zooms to great alti-tudes.

The Blackbird XC has a span of 107inches and an area of 2300 squareinches. The last one we built weighs162 ounces for a wing loading of justover ten oz/ft2 and is an incredibleflying machine. Due to its size, itcruises sedately through the skybetween thermals. Once in rising air,the low aspect ratio of the planformand the light wing loading makeclimbing fairly easy. All of the sheetingon this aircraft, with the exception ofthe fin, is 3/32 inch balsa. The Black-bird XC now under construction willbe sheeted with 1/16 inch balsathroughout, not only reducing theoverall weight of the sheeting, but alsodecreasing the amount of lead placedin the nose. As an example of thisweight saving, each wing for the lastversion weighs 48 ounces, the newwings will likely weigh between 32and 36 ounces. The projected flyingweight should therefore be well under

162 ounces, and we anticipate a wingloading of under 9 oz/ft2.

We’re using Hitec HS-605BB servosthroughout — one for each elevon, onefor each flap, and a fifth for the rudder.These servos are close to the size of astandard servo and come equippedwith dual ball bearings and helicalgears. This servo can put out 77 oz. in.of torque at 0.16 sec./60 degrees on 4.8volts. These “high torque” servos wererecommended by John Packer, themanager of Hobbytown in ParklandWA, and we’re extremely pleased withthem.

Vertical fin and rudder

After putting rudders on our twometer Blackbirds and finding a notice-able improvement in handling, wedecided to add a moveable rudderduring construction of this XC ma-chine. This dictated a redesign of thefin so that the hinge line would not beswept back so severely. The leadingedge of the wing is swept back tendegrees, and we swept back theleading edge of the fin 20 degrees.Since the hinge line is located at 50% ofthe local chord, it sweeps back at tendegrees. Additionally, the moveable

rudder will be of open frame construc-tion with diagonal ribs rather thanfully sheeted. This should save someweight compared to the same surfacesfully sheeted. The included 3-view(Figure 1) shows the old fin planformand the redesigned fin and rudderassembly.

Because of the large chord and ex-pected flight speeds, we wanted anairfoil of about 10% thickness. We alsowanted an airfoil with a smalldeadband around neutral. The S 8020seemed to meet our needs, despitesome recent notes which state thedeadband is slightly larger thanoriginally measured.

Because of the modified fuselageshape, the already large sub fin wasmade deeper. We also wanted to makesure that upon landing the wingwould be driven to below its zero liftangle of attack.

Airfoil

Our previous versions of the Blackbirdhave used the CJ-3309, the CJ-25209,and the BW 05 02 09 sections. Theseairfoils differ from each other insignificant ways.

Page 5April 2003

R/C Soaring DigestPage 6

The elevon servo is mounted right behindthe main spar. Notice the high strength

clevis and pushrod. The Hitec HS-605BBservo puts out 77 oz. in. of torque, so the

system has to be of more robustconstruction than the usual.

The complete flap and driving servosystem. Each flap is 18 inches longand three inches wide. The leadingedge sheeting is not yet in place. A

rolled paper tube acts as a conduit forthe elevon servo cable.

The flap hinges are inset into the 1/16inch balsa sheeting, then covered with 1/

64 inch plywood. The outside edges ofthe plywood were rounded with

sandpaper before being glued in place.

(Left) The flap servomounting and pushrod

system. The hinged edge ofthe flap is toward the left.

The CJ-3309 has a flat lower surfacefrom the leading edge radius back tothe point where the reflex starts at 75%chord. Building a warp free wing on aflat surface is therefore automatic.

The CJ-25209 has what’s commonlycalled a “Phillips’ entry.” The lowersurface curves upward from 25%chord forward to the leading edgeradius. This reduces the camber fromthree percent to two and a half percent.Flight speeds appear to be slightlyfaster with this airfoil than when usingthe CJ-3309. Launch height is greaterbecause of the lower drag, allowinghigher zooms, and climbing ability in athermal is not noticeably affected.

The third section, the BW 05 02 09, hasno flat portions on either the upper orlower surface, making a constructionjig of some sort a necessity. We reallylike this airfoil because of its low dragand reduced reflex. The CG location isin exactly the same spot as the versionwith the CJ-25209 section, but thenatural oscillations in pitch whichappear when flying straight ahead forlong periods are slower and of lessermagnitude. The performance improve-ment over the CJ-25209 is remarkable.Energy retention during zooms off thewinch are consistently higher, cruisingbetween thermals is noticeably faster,and the aircraft is more quiet.

Despite the more convoluted construc-tion methodology, we chose the BW 0502 09 for this aircraft.

Flaps

The topic of flaps on planks was asubject of our correspondence withDave Jones, designer of the Blackbird2M. While such flaps cannot be used toimprove thermal climb, they can beduring winch launches to improveinitial climbout and for glide pathcontrol during landing. The general-ized “rules” for flaps on plank plan-forms are as follows: location of theleading edge of the flap at 40% of thelocal chord; approximately 5% of thewing area; deflection of 45 degreesshould be sufficient.

The flaps are 18 inches long and threeinches wide. They consist of 1/16 inchbalsa exterior and interior sheeting,and 1/8 square spruce diagonal ribs.The control horns are mounted onplywood triangles which fit into the

corner under the servo output wheel.The flaps are lightweight and torsion-ally rigid. We used standard nylonpinned hinges, five per flap. OurDremel was mounted on a router baseand just enough balsa was removed forthe hinge to be flush with the flap andwing sheeting exterior surfaces. Wethen cut 1/64 inch plywood into theshape of an aerodynamic strut andused that to cover the exposed surfaceof the hinge.

We’re using Hitec HS-605BB servosthroughout — one for each elevon, onefor each flap, and one for the rudder.These servos are close to standard size,have dual ball bearings and helicalgears, and can put out 77 oz. in. oftorque at 0.16 sec./60 degrees on 4.8volts. The flap control system utilizes ashort pushrod with ball links at eachend. The servo wheel is set so thatthrottle trim (low speed) adjusts theclosing position, and when the flap isfully deflected there is no pressureagainst the gear train. See Figure 2 andthe flap servo photo.

We settled on a Y-harness for the flapservos. This allows us to use thethrottle channel for controlling flapdeflection, the aileron and elevatorchannels for the elevons, and therudder channel for the rudder. Theflap servos were mounted in mirroredpositions in the wings, so one servohad to be modified for reverseddirection of rotation. Our original planwas to use a Hitec seven channelreceiver and mixing options on thetransmitter, a JR PCM 10. This channelutilization allows us to use our FMAM5 with additional protective foamsurrounding it, and our JR Century 7transmitter should the need arise.

Fuselage

The Blackbird 2M per plan fuselage

Page 7April 2003

(Right) A visual comparison of theBlackbird XC.2 (front) and Blackbird

XC.3 (rear). The new XC.3 has lessinternal volume, but is far superiorfrom an aerodynamic perspective.Note that the steel wing rods are

inserted into both fuselages. The wingplacement is therefore parallel.

View of the left front of the fuselage nose.1400 mAh battery pack, Hitec seven

channel receiver, and vertically mountedrudder servo. Still plenty of room in the

forward nose for lead ballast to adjust CGlocation.

Another view of the forward fuselageshowing the location of the various

electronic items. The receiver location wasframed for the Hitec seven channel, but theFMA M5 will be used with lots of room for

protective foam.

The fuselage nose with side blocks in place.The area in the region of the wing spar is

still open. Fiberglass and resin are still to beapplied.

construction consists of 1/8inch plywood sides whichmatch the wing root profilefrom the high point to thetrailing edge. From the highpoint forward, the fuselageside view is similar to theairfoil. The rectangular crosssection at the high pointgradually blends into a solidnose of roughly circularcross section as the plywoodsides bend inward. Theinternal volume is incred-ible. A four cell 1600 mAhsub-C battery pack forward,receiver behind. Without arudder servo installed,there’s more than enoughroom in front of the spar fortwo Ace thermal sniffers.

We desired a fuselage with acylindrical cross-sectionfrom the nose to the inter-section of the wing at theexpense of internal volume.Our original thought was toconstruct a central keel anda slip-on nosecone. Wesketched out the side viewin full size, then drew incircular cross-sections fromthe nose to the high point ofthe wing root. In looking atour creation, it becameobvious that a slip onnosecone would not bepossible because of thefuselage curves as seen inthe side view. Our decisionwas to retain a central keeland form large balsa sides ofbalsa block.

Fuselage construction beganwith the keel. Two pieces of1/16 inch plywood were

glued together to form the 1/8 inchthick main portion. This part of thekeel is mounted to the main spar wingrod at the rear and to a 5/8 inch dowelnear the wing leading edge. The dowelis a lightweight method of establishinga good carrythrough between the keeland the wing roots and acts to preventcrushing if the wings happen to swingforward on a rough landing. Addi-tional rims of 1/16 plywood wereglued to both sides of the keel. Moreabout those rims in a bit.

A few of our last construction projectshave utilized large carved and hol-lowed blocks. We’re getting to bepretty good at the shaping process andhad a large balsa block of the correctdimensions to work on. Blocks werefirst run through a jig saw to give therough profile, then tack glued to bothsides of the completed keel. An X-Actocarving blade, a freshly sharpened lowangle plane, a razor plane and carbidesanding bars were used to get thefuselage to match circular templatesfabricated from credit cards.

After external shaping, the blocks werepopped off the keel. Holes were drilledaround the perimeter of the keel toserve as holders for several mounting/alignment pins. The nose blocks werethen reattached with wide maskingtape and the holes in the keel used toguide the drilling of matching holesinto the nose blocks. The nose blockswere removed and hollowed using aDremel and a carbide grinding tool.The holes for the pins were coatedwith thin CA and then cleared by handusing a matching drill bit.

The keel is quite sturdy by itself. It’svery much stronger with the sideblocks attached, and we’re sure thestrength will increase further with the

additional layer offiberglass which willencase the entirefuselage structure.

Other modifica-tions and details

The spruce spars aretapered in widthfrom 3/4 inch at theroot to 3/8 inch at thetip. This is wider atthe root and morenarrow at the tip thanscaling the spar caps

R/C Soaring DigestPage 8

as indicated on the two meter plans,where the width should be constant forthe entire length of the spar. The sparwebbing is also heavier at the root andmore light at the tip than would beindicated by the two meter plans. Asmentioned before, the completed winghas no carbon or Kevlar, yet is strongenough to withstand full powercontest winch launches with a barelynoticeable flex at the root.

As is now our usual practice, theelevon servos are located in the wingbehind the spar and directly in front ofthe inner edge of the elevon. Thisallows a direct linkage between theservo output arm and the servo controlhorn. Additionally, the Frise typeelevon has been eliminated. Thisversion will once again use simplefabric hinges at the upper surface.

The rudder servo is mounted verticallyon the keel directly in front of theleading edge of the wing. The pushrodcable consists of 1/16 inch music wirethrough a yellow ridged NyRod whichgoes through a red NyRod. Thispushrod goes below the 5/8 inch

R/C Soaring Digest556 Funston Drive

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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.

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GONE SOARIN’Zika

dowel which traverses the fuselage inthe forward part of the wing.

In the past, we’ve run the antennaalong the leading edge of one wing. Inthis version, the antenna is routedbehind the rudder servo, down theright side of the fuselage and up thefin.

The rudder servo is connected directlyto the receiver with a shortened cablewhile the flap and elevon servosrequire cable extensions within thefuselage. The elevon servos alsorequire 24 inch cable extensions withinthe wing. All servo cables are cut tominimum length and twisted to inhibitspurious noise being introduced intothe signal paths._____

Suggestions for future columns canalways be sent to us at either P.O. Box975, Olalla WA 98359-0975 or<bsquared@appleisp.net>.

n

Page 9April 2003

GORDY’S TRAVELS

Gordy StahlLouisville, KentuckyGordySoar@aol.com

Balance Affects Landings!

In my recent past articles I talkedabout how to find the ‘balanced’

point of a full flying stabilizer thermalduration sailplane. I talked about howa ‘balanced’ model is free to indicatethe smallest lift, turn tighter slowerand safer, and land slower.

Most guys I meet react with the usualover reaction of: ‘rearward’ balancedmodels are uncontrollable. As if‘balanced’ meant un-balanced.

I often ask them this question, “If youbalanced your model according to mysystem, and it flew slower, indicatedthe smallest lift, turned tighter atslower speeds, needed less surfacedeflection and landed slower, thentook it home, measured the balancepoint, found it to be 2” behind whatthe plan showed – would you move itup to the plan mark?”

I seldom get an answer. But there is areason to move the balance pointforward from what seems to be a reallyoptimized balance point! And I figuredit out today at the flying field.

I had brokered a purchase of a sail-plane for a relatively new full functionsailplaner, and decided to set the planeup for him. I flew it as it came from atalented contest pilot, and found it tobe a real dog. To be fair, the wind andhumidity weren’t the best for TDflying. But the model really was NOTmy cup of tea... Sluggish on rudder,quick to stall, and tight thermal turnsspiraled downward.

So, I flipped it upside down to checkthe balance, only to find that it was

carrying a considerable amount of leadin the nose. How could that be, whenthe guy who had it has won a lot oftough contests? Simple. Many of uslearn to fly the models we have, well.

I pulled all the lead out (about anounce or so), then launched again.Inverted showed that it didn’t needany down to keep it flying level, so Iwent looking for thermals. It flewgreat! No problems what so ever; itshowed lift, rudder yawed it like it wason rails. It wasn’t till I brought it downfor a landing that I found that it wasnot ‘balanced’.

It tracked in on line to the spot withouta hitch, smooth in yaw, pitch and roll,until I poured in some landing flap;then she popped up and wallowedaround. No way I was going to make itnear the spot.

Turns out that the balance point wasdead on, for the chord of the un-flapped wing.

Learning about balance can only bedone through experimenting. Gettingyour model optimized will allow youto spend more time learning to readair. Have you found that point that isperfect for your un-flapped chord?Then added in some nose weight to getyour model set for all conditions?

So many of us move from one new‘super’ model to the next, only to findthey all seem to fly as disappointing asthe last. Maybe it’s because they are‘hobbled’ by the balance and trim setups. If measuring a CG is what you’vedone in the past, why not give flying todiagnosis balance instead? Balance tofly, not to match some drawing.

Give it a try; you’ll find that the planeyou have may be the plane you havebeen paying for! I did! n

R/C Soaring DigestPage 10

Mark Gellart flying theStealth Sloper in the XC

event at the NATS.

Stealth Sloper over the dunes of LakeMichigan near Luddington.

Toledo Show

This column is dedicated tosoaring vacations. If you have a

favorite sailplane saga, considerwriting it down for RCSD. If youare planning a vacation thatincludes your plane and transmit-ter, consider making notes as yougo, and working up an article later.Take photos. Collect maps. Andsend your story to Tom Nagel attomnagel@iwaynet.net for gentleediting and suggestions.

Tom

HAVE SAILPLANE, WILL TRAVEL!

By Tom H. Nagel904 Neil Ave.

Columbus, OH 43215tomnagel@iwaynet.net

The Stealth SloperA travel sailplane from “Have

Sailplane, Will Travel!”

Afew years ago my son and I wereat the Weak Signals RC extrava-

ganza in Toledo. Robart had justintroduced a line of molded styrofoamtoy hand-toss gliders, and I bought onefor Andrew, an F-117. Robart was alsoselling toy gliders styled like a UFO,and an F-16. At the time the Robartrepresentative had at least one of themodels fitted with an 049 engine andservos. The little F-117 was nicely

done, but proved to be a lousy toyairplane. It didn’t glide all that welland mostly wanted to roll inverted anddork in. We hung it up in the garageand generally forgot about it.

Two things brought the F-117 back tomind recently. The first was the adventof Gulf War II, Act Two of the War ofthe Bushes. The second was that flyingbuddy Chuck Rumele had installed alittle GWS receiver and some servos ina little toy styrofoam flying wing he’dfound at an RC swap shop. With the F-117 back in the news and Chuckflaunting his inventive craftsmanship, Iremembered the little Robart foamyand took another look at it. The timeseemed right. The cheap GWS receiv-ers and servos on the market certainlymade the conversion of the little gliderto a sloper a more attractive opportu-nity. I got out the Dremel.

For those of you who haven’t seen theRobart toy F-117, it is small and light,

Page 11April 2003

Jim Carlton (not shown) on theCleveland Lakefront Park.

(Below) Cumberland,Maryland Slope Fly-In.

Terry Edmonds landing the stealth sloperin the Scale competition at the NATS.

spanning only 18" and 19" in length.Still, that is 171 square inches of wingarea. The glider comes equipped witha set of stick-on markings for thecockpit, inlets, and so forth. The V-tailis molded separately onto a block offoam that fits into a recess at the rear ofthe fuselage. There are four recessesmolded into the bottom of the wing,one forward for modeling clay ballast,and three behind that for finger holes

Using sanding blocks I smoothed offthe rough edges here and there, andstarted sanding a taper into the trailingedge of the glider’s wings. Those TE’sare molded fat and square. I taperedthe bottom surface of the wing, left thetop surface more or less flat, andthinned the last few inches of winguntil it was down to about half itsoriginal thickness. I added a piece ofEPP cut into a sharp wedge shape forthe nose of the plane, covering andattaching it with black electrical tape.

Next, I built elevons to tape onto thetrailing edge of the wing. The first set,out of 3/4" TE stock looked too small. Ibuilt a second set out of 1/8" balsasheet. They are cut to match the TE ofthe wing and are roughly 6" long and1" wide. I sanded a taper into theirtrailing edges and a 45 degree bevelinto their leading edges. Control hornsI cut from some leftover counter topsamples, the little pieces left afterbuilding some RDS driver pockets. Iglued these into the elevons andcovered the elevons with blackmonokote.

The battery, receiver and servos camefrom a crashed Pico Stick electric parkflyer. I had a couple of GWS 7-cell 110mah nicad packs that Nimh Technol-ogy had orphaned. I cut them down to4-cell receiver packs. Then I masking-taped the 4-cell pack, the servos, thereceiver and the elevons right onto themodel glider in the places that Ithought likely, to check how thatchanged the center of gravity. It waspretty close. Time to warm up theDremel.

The Dremel’s grinding stone is a greatway to cut servo pockets in styrofoam.It took almost no time to cut out twoservo pockets, and a recess for theGWS receiver. I also enlarged the frontballast hole into a slot for the 4-cellbattery. Using the router head and aruler, I cut grooves for the servo andbattery wires. The plane came out atabout 5 ounces, or a wing loading ofabout 4.2 ounces per square foot.

Almost all of the on-board equipmentwas recycled stuff. Even the wirepushrods were recycled from the oldcrashed Pico stick. All of the gear,including the elevons, was put in or onwith clear packing tape. The only newpiece of equipment was the spiralwound indoor-RC antenna. These little

and throwing. The rear-most hole ismore or less on the proper CG point.

My first move was to toss the glider tomake sure I had the CG more or lessclose. It was, and the glider was still acrappy flyer. I marked the CG on thefuselage top and bottom, and then dugout the modeling clay ballast from thefront hole.

R/C Soaring DigestPage 12

gizmos really work, cutting downstray signals for the little singleconversion GWS receivers, and at thesame time providing a neat, compactinstallation.

I recruited Andrew to help me handtoss the F-117. It turned out that theneutral elevon setting involved a bitmore down trim than I would haveexpected, but once that worked out,the model glided much better with RCcontrol than it ever had a free flighter.Time to hit the slope.

My test slope is a small hill behind achurch near my office. I tried out the F-117 in brisk west winds. The plane wastwitchy in roll and needed a lot offlying, definitely not a hands-offfloater. But elevator response wasgood and the trim was right on. Themajor discovery in the first slope flightwas that the plug-in V-Tail is fragile. Ikept the plug in block but I rebuilt therest of the tail out of black meat traystyrofoam, which gave me a chance tothin the profile of the tail for penetra-tion purposes, to make it stronger, andto color it stealth black, like theelevons.

In mid-April I finally got a chance totry the stealth sloper on a real slope inreal wind, 20 to 25 mph out of thesouthwest. A little less wind mighthave been better; the stealth had somedifficulty punching out through thewind to get in front of the slope. Still, itflew pretty darn well for a recycledkid’s toy. The stealth has a quick rollrate, and a little exponential helped alot. Axial rolls were easy. Loops weredifficult, ending in a vertical invertedstall and back flip. Slope landings werecontrollable, and crashes (of which Ihad a few) were survivable. The pointyEPP nose worked well.

An un-planned encounter with aguardrail ended the flying day, but thelittle F-117 went back together on theworkbench with some fast epoxy.

The Stealth Sloper has a number of keyadvantages. It is small and cheap. It iseasy to pack along on a trip. In a pinchit is disposable.

Another advantage is that you don’tactually need to fly it. You can leave itin the car. For that matter, you canleave it home on the workbench. Youcan just stand on the slope with your

transmitter in hand and grin into thewind. If folks ask what you are doing,just point out vaguely into the air andtell them you are flying your StealthSloper. I have included photos ofvarious notables flying the StealthSloper at locales around the Midwest.

Robart Mfg. apparently still makes theF-117. It is available for under $10 froma number of toy outlets on the internet.Try kidstoysplus.com, for example.

Sources:

Robart Mfg. Inc.PO Box 1247625 N. 12th StreetSt. Charles, Illinois 60174

www. Kidstoysplus.comsells Robart toy gliders

www.happyhobby.comanother source for the glider

Grand Wing Servo, makers of smallcheap onboard electronics, plus awhole line of airframes and electricmotors.

Indoor RC antenna:from Dave McCarthy at LiteflyRC.com,

614-539-9259Azarr makes a similar unit,

www.azarr.comalso available from DJ Aerotech,

djaerotech.com

Slope Photos courtesy of the CentralIntelligencia Agency (HSWT)

n

Page 13April 2003

On March 15th, seven members ofthe Silent Flight Special Interest

Group of the Valley Aero Modelersvisited the LeClercq home for aninteresting and delicious meeting.Sally prepared delicious salads, soupsand finger food.

Like most other AMA clubs we aremodifying our constitution and fieldrules. We discussed the proposedsafety rules and etiquette guidelinesfor using the sod farm. However, mostof the time we were talking about whatwas going on in the sport. We noticethat it is more difficult to get new fliersto become part of the RC modelingscene. The models are either tooexpensive or take lots of time toconstruct.

We would like to have more publicexposure and think we can do betterby attracting spectators and even havethe cable TV company cover ourevents. Perhaps take some membervideos and air them on TV. We justhad a model show and auction inwhich we demonstrated video telem-etry with a model flown off frozenLake Winnebago.

This would take some work but wejust might find someone who can mixand edit a great program from DaveBeck’s electric and solar powered XCflights and Rob Lehman’s sky camvideos (electric glider and wet pow-ered model).

Some things I learned during our visit.Fran is now 77. He has on display amodel just like the one he made andflew in 6th grade on the playground.He has some old models hanging onthe wall like a triplane that wascontrolled by a Proline radio; an earlyRC unit that was good in its time butwas big. He had photos of him and hismodels as a young man. The aileronson the top wing were powered by alarge servo in the fuselage and asquare tube to rotate a servo wheel inthe upper wing. Fran is still living inthe Bond Street home he built withouta mortgage as money permitted. Theextra spaces, like kitchen cabinets, arenow filled with transmitters while thefridge has batteries and chargingequipment as shown in the photos.The kitchen that does the actual

cooking in the house is in his house-keeper Sally’s apartment that is justbelow the level where Fran lives mostof the time. Sally has been Fran’shousekeeper for as long as I haveknown him (20+ years).

Check out the photos of the models inthe fine wood cases. The one shownhas two unlimited sailplanes in it. Oneis a Spectrum and the other will gowithout a name since Fran couldn’trecall what it was called. Hangingfrom the ceiling are two Graphites, aProbe, a Dodgson Lovesong, andseveral others.

Fran’s abilities as a craftsman often arecalled into use as we ask him to repairparts of our high tech models wedamage during the flying scene.During our summertime weekly flyingsessions and contests, Fran operatesthe VMC retriever. On rare occasionshe flies his models but he takes greatenjoyment in seeing others includinghis sons, Dave and John, fly hisbeautiful models. It doesn’t get anybetter than this for a club to have amember like Fran in your midst. n

by Lee MurrayAppleton, Wisconsin

Visit to Fran LeClercq’s Shop

R/C Soaring DigestPage 14

Dave RegisterBartlesville, Oklahoma

regdave@aol.com

TECH TOPICS

This is an often-discussed topic inthe magazines, web sites, chat

groups, etc. As more pre-moldedaircraft prevail in the marketplace, it’sa good idea to know how to repairthem. We always envision our latestcreation or acquisition lasting foreverbut experience says that if it lasts oneseason without a serious ding, you’redoing pretty good.

This little article is not intended to be aprimer on the subject. Much hasalready been written by a great manyfolks who know a lot more than I do.But I did have a recent occasion forsome re-construction of my Omega 1.8and think I learned something usefulfrom the experience.

One lesson to be learned from thiscrash is to be sure you know whichplane you’re flying. Computermemory is great but when you dosomething stupid, it’s pretty unforgiv-ing.

In this case, after a long, medicallyenforced absence from flying, the dayfinally came to get back to the field. Sonaturally there was a little apprehen-sion anyway.

When I got to my favorite schoolyard,3 or 4 young people were rollerblading in one of the parking lots andcame over to ask all the usual ques-tions: how much does it cost, whatdoes that little thingy do, why arethere so many buttons on the radio,etc., etc.

Well, between trying to satisfy the kidsand trying to assemble the airplane, Iforgot to call up the right aircraft. Sothe Omega went into the air with myWhisper 2M control setup. Not good!

I’m not sure which scattered faster,those kids or the pieces of the fuselage.

It turned out that the fuselage wasbroken in about 6 places but every-

Once the CA kicks off, you now have apiece of aircraft that you can pick upand handle. In the cockpit area, a fewlayers of 0.75 to 1.5 oz. cloth on theinside surface will restore mechanicalintegrity. I use West Systems forrepairs like this, not 30 minute epoxy.If you don’t slop too much resin inhere, things will be nice and strong.You don’t need a high quality finish inthe interior but don’t go too heavy onthe resin either.

It’s the outside that’s really a problem.You want things to look right but oftenthere are lines, ridges and little chunksmissing. Fill the gaps with some of theleftover resin from gluing up theinterior (before it sets!). At this point Imix in enough micro balloons to makeit pasty so it wont drool after you’veput it on.

Following full cure of the biggest gaps,rough sand the exterior globs - themicro balloon filler sands very easily.But you still have the lines from thecracks and some other dents and nicks.Here’s where a neat idea really helpedme.

A Fiberglass Fuselage Repair

thing else was more or less intact. Somaybe we can do something with thisbaby after all. A careful search in andaround the crater was made to gatherall the big stuff to see what could bedone.

Once everything was cleaned up, itlooked like the pieces could be putback together with very few gaps. Theprocedure went something like this.

After the radio and motor wereextracted and cleaned up, the fuselagepieces were put back together usingCA and a light dusting of filler. I usethin CA and then use a small squeezebottle to dust the glue lines withbaking soda. This is a bit like re-assembling a jigsaw puzzle and itneeds to be done with very carefulattention to alignment.

(continued on page 15)

Page 15April 2003

Prepare a few strips of fine weaveglass for the exterior repair. 1/2 oz. to3/4 oz. will do. Also cut up some peelply that will be larger than the re-paired area. If you’re going around acompound curve, cut this into longstrips that won’t wrinkle too mucharound the curve.

Now mix up some microballoons inthe West systems. Not so thick thistime. Wet the area to be repaired (asolder brush works nicely), lay on theglass strips and then add the peel ply.When you put on the peel ply, tapeone end of it to a good section of thefuselage and then pull it very tightacross the resin/glass area. The stripneeds to be long enough that you canthen tape it down to a solid area of thefuselage on the other side of thedamaged section.

Repeat with each strip of peel ply untilthe entire area is covered. If you’vepulled hard enough, two thingshappen:

Path to Improvementin Thermal Soaring

By Bill KuhlBkuhl@luminet.net

fishing, and many other things, luckshould be a decreasing factor in yoursuccess as you improve.

The objective of this article is to discussattitude and approach to improvingthermal flying skills, not so muchtechnical details covered in many othersources. It is about breaking down theelements and practicing smaller partsbefore trying to perfect everything atonce. Hopefully I can offer a couple oftips that have helped me.

In writing this article, I came up withseveral points that were important tome.

Attitude

Your success or failure has more to dowith controllable factors than by luck,good or bad. Seemingly small factorsadded together can give big results.The skills will not be learned over-night; if they could be it would not besuch a challenging, interesting hobby.

Adjusting Your Attitude

It is only natural to think that the smallthings really don’t matter, how could aslight difference in the curve of a wing

make a difference? In an activity that isso much about efficiency, all the littlethings together can make a hugedifference. One of the biggest attitudesto overcome is that your skills don’tneed improvement. Contest flyingshould prove to you that there is roomfor improvement.

The fair weather attitude is one Iadmittedly have problems with,practicing only on days with lightwind and plenty of sunshine, will notmake you a competent contest pilot.Besides, when you try to fly on theslope in 30 mph winds, it will be atraumatic experience when landingwithout some windy weather experi-ence.

If you have power plane experience,following thermals will take somechange in your flight paths over thefield. As Dave Thornburg stated,“Thermals don’t care about fieldboundaries, tree lines, and such.” InThornburg’s video I thought he madeit seem like thermals travel in astraight line downwind. Paul Naton inhis “Secrets of Thermal Flying “ videoshowed graphics of how the path of athermal downwind can take many

1) You force the resin into the glasscloth, and

2) The excess resin bleeds out throughthe peel ply.

At this point, your repair looks RE-ALLY ugly. Have faith. Set it aside for24 hours, then come back and pull offthe peel ply. What’s left behind is avery well wet out repair with no excessresin and maybe a few small ridgesthat can be wet sanded out with verylittle effort (this is where the microballoons really help).

After wet sanding, hit it with primer tofind any little pin holes and fill those.Prime and wet sand, then spray withthe best color match you can find.

For the tail boom of a glass fuselage,it’s even easier. At this point it’s hardto get to inside the boom so we’reworking on the outside. Again, re-assemble with CA and a sandable fillerand be sure the alignment is REALgood.

Wet sand the fuselage to expose theglass all the way around. Then use theresin micro balloon mix to coat therepair surface. Lay down 2-3 layers of3/4 oz. cloth and then spiral wrap theboom with peel ply. Tape one end andpull it pretty hard across the repairarea. Tape the other and then leave italone for 24 hours.

After the resin has cured, remove thepeel ply. Most of the excess gunk goeswith it. Sand and prime as before andyou’ll wind up with a very strongrepair with little, if any, visible signs ofirregularities after you’re done.

A couple of pictures of the break in theOmega boom are shown as an ex-ample. One round of primer and wetsanding was all it took to get back tonear original quality.

The Omega is back in the air again.Now if I could just fix that brain-glitchabout which program to run withwhich planeÖÖ.

n

Introduction

After my first year of sailplaneflying, I thought I was a fairly

competent RC sailplane pilot. Thesecond year of flying, my flyingimproved significantly also, in factevery year I seem to improve some.This made me realize this is a hobbythat will provide continuous chal-lenges. The first couple years, I oftenblamed the conditions for difficulty inthermalling, as my skills improved Ifound success staying up in lift in moreconditions. With sailplane flying, (continued on page 16)

R/C Soaring DigestPage 16

twists and turns in the path down-wind. This appears closer to real worldconditions in my opinion.

Practicing the Parts

Selecting, building, and trimming asailplane has been covered in manyarticles; what is important, is to have agood flying sailplane. If the sailplane isfighting warps or the center of gravityis incorrect, the performance suffersgreatly. A sailplane that thermalseasily, will give you more practiceflying in thermals.

The areas I practice revolve aroundfinding the strongest lift and makingthe most of the lift by smooth flying.Through practice learn to recognize theground signs, and fly in marginal liftconditions to practice smooth flying.

Practice RecognizingGround Signs

indicator like the free flighters use.What I found was that the temperaturechanges were pretty small, normallyonly a few tenths of a degree. Windspeeds changes were more dramatic,often jumping up and down severalmiles per hour within a short timeperiod. Eventually you get to the pointwhere you feel it is getting warm oryou feel the changes in wind speed, ordirection on your body.

Recognizing Changes in Speed

Along with ground signs, developyour skills in detecting lift by watchingyour airplane. Recognize the changesin speed. With hours of practice thelittle changes in speed were morenoticeable to me. Observing thesailplane suddenly pick up speed wasa very clear indicator to me that it wasin lift. Not as obvious was when thesailplane was slowing down, it wasmost likely in sink. Recognize whenthe plane is working hard to penetratethe wind, this is really killing perfor-mance. If the plane is inside thethermal it shouldn’t have to work sohard trying to penetrate.

Practicing, Smooth Flying

With a limited amount of energy, notwasting it is very important. Youmight think your flying is smooth, butpracticing flying in margin lift condi-tions may prove there is room forimprovement. Recognize that anycontrol inputs you are using arecreating drag. Think about your flyingin terms of energy. The plane is flyingwith only so much kinetic energy;unnecessary movements such as extracontrol movements, stalling, or sharpturns, will bleed off the kinetic energyvery quickly. The smaller the plane,the worse this will be.

Tight thermal circles turns take a hugeamount of energy; if the plane is notcircling in lift, the potential energy ofaltitude is being lost. This means it isbest to have a high degree of certaintythat you are entering lift; if you hitweak lift, adjust quickly to findstronger lift, or straighten out to fly outof sink.

Learning to Fly Smooth– Ways to Practice

Fly in conditions of lighter lift; I oftenfly later afternoon, early evening. Withpractice I am climbing in lift later in

the day consistently.

Practice flying with an underpoweredelectric slow-flight plane and try formaximum duration. I noticed that aslow-flight plane of mine would barelyclimb when other people were flying it(beginners and glow-powered pilots).Most of my flights were of consider-ably longer duration and of higheraltitude because I was using less andsmaller control inputs.

Practice flying smooth by flying fromsmall slopes; to stay up on a smallslope takes very smooth flying, recog-nizing when the lift is decreasing orincreasing. When the plane is climbingin lift, that is the time to turn. Whenyou are in the core of the thermal, thisis when you can experiment withturning tighter to see if the plane goesup even faster. Keep working to havethe plane climbing around the entirecircle.

Circle in the lightest lift as long aspossible. Often with my hand launch Iwill try to locate lift until I catch theplane, then quickly throw back wherelift was spotted and proceed to climbout. When the plane is circling 15 feethigh chances of climbing out are notvery good, but you can easily see whatis going on with your plane.

Location, Location, Location

As important as location is in realestate, so is finding the exact locationof the thermal core. If you are notflying in lift, it doesn’t matter howefficient your glider is or howsmoothly you are flying. Even thoughyour sailplane is gaining altitude, itmight not be in the strongest part ofthe thermal. The “Secrets of ThermalSoaring” video from Radio Carbon Artdiagramed the strength of lift byassigning numerical values to lift orsink, with sink represented in negativenumbers. If your plane is flying in thelower number positive lift, it is veryclose to the negative number sink.Working toward the strongest liftincreases chances of avoiding sink.

Putting It All Together

I hope these suggestions might helpyou improve your thermal flying, atleast a little. Nothing earth shatteringhere, but if you work to improve allthe small components, it can add up tobig results. n

Many articles have been written aboutusing the shifts in wind and changes intemperature to locate thermals. Theseare often subtle signs, especiallychanges in temperature.

With repeated practice over time youbecome more sensitive to changes intemperature and wind speed anddirection. Try to correlate winddropping, and finding lift directlyupwind. Notice when all of a sudden itgets much warmer right where you arestanding.

What makes spotting lift tough, is thatwhile you are trying to figure outwhere the lift and sink might be, youalso have to fly the sailplane. You haveto become so comfortable flying thesailplane that your brain can thinkabout other things.

At first you might want to havedevices to help with this, such asthermal flags. Besides a thermal flag, Ipurchased an accurate wind speedindicator and a heat-sensitive thermal

Page 17April 2003

Once you have noticed all you feel youcan, make a search pattern plan, andfollow it. It’s a big ‘Duh!’ if the planebefore you went left and it sunk like arock, pretty much assured of a spec-tacular one minute flight; you shouldchoose a right turn off of launch.

If there is a gaggle of planes in greatlift, definitely do a ‘turn and burn’ offof the launch to get over that way.Once there, don’t be in a rush to getright in with them. Move past them tosee if they are really just on the frontedge of the core, or the back edge. Ifheading to a gaggle, do not take youreyes off of your plane, and advise yourtimer to do the same. It’s easy to losewhich model is which.

Recognizing lift

If you read my previous articles, thispart is redundant, but important. Ifyour model is balanced (As opposedto, “I set the CG according to the planewith a micrometer.”) then when it is inlift it will signal and confirm. It willsignal via the tail popping up and thecontrols getting really lively. Once youfeel that is the case, then by simplyhitting your rudder either directionyour plane will circle upwards if thereis lift, or downwards if you are in sink.Your controls get lively because thereis air (energy) rushing up underneathfor your plane to slide forward off of.They become sluggish because there iscold air dropping on top of yourplane’s tail, sticking the nose up,slowing air moving over the controlsurfaces.

If your model is ‘set dead on the CGaccording to the plan’ chances are itwill not signal or confirm anythingother than the fact that you will begetting skunked on that flight.

Launching into lift

You can tell that you launched into liftbecause your wings ripped off. Youcan tell you launched into lift by thesound of the winch really laboring.You can tell you launched into liftbecause your launch was really verticaland your altitude seems really good.

When you hit lift on a launch, don’t layon the pedal! Kite your model up

Pretty often during my travels toyour flying sites, I notice that pilots

often launch through lift, fly throughlift, fly away from lift or circle on theedge of lift... That’s okay if I am flyingagainst them in a contest, but mostlyit’s frustrating because I know I havedone it for years myself.

With all my flying you’d think that Iwould never miss my times or alanding but, in fact, like most of usmortals, sometimes I head the wrongway too or do a dumb thumb onapproach.

But one of the benefits of flying sooften is that my frustration inspired

GORDY’S TRAVELS

Ten Tips That You Have Found Lift!

Gordy StahlLouisville, KentuckyGordySoar@aol.com

me to identify cues and hopefully beable to explain them to the rest of us -not something the soaring legends aregood at. They’re great sailplane pilotsbut not very often talkers.

So let’s talk!

Devise a flight plan

Prior to launching (and this assumesyou have read and put into practice thethings I have written prior about trim,balance and its effects on reading air)take a look around the flying site. Lookfor the obvious signs like birds circling,dust devils, big dark clouds, or onegroup of trees moving on a tree line.Look for a tilled black field, or a bigbuilding that might be collecting heat.Duh, look at what other planes aredoing, but don’t count on them to goto lift. Watch their travel path to seewhat kind of air they are passingthrough, as in did you see themwobble, or perk up their tails, or getsluggish and droop tailed? Take thewind speed into consideration too; itcould mean that, once in lift, you willhave to aggressively bank and crank,with tight moving circles to stay in thecore.

R/C Soaring DigestPage 18

ZIKA

instead taking all the line in, more lineout – more altitude on release. Fast,short duration tapping, just to keep theline taunt (sort of like keeping beatwith your foot to a fast Polka.

Only stand on the pedal at the very topof the launch, then let off and just pullyour plane up AFTER you let off thepedal – do not bother with going in the‘bucket’ with a big dive and pull up.

Once off, circle search the area for asignal, then ask for confirmation byhitting rudder. I know that rudderthing has you freaked because you’venever touched it except accidentally,but you paid a thousand dollars forwhat you think is the most trickairframe design out there, loaded it upwith really expensive servos, yet don’tuse one of the most important parts ofit: the rudder. So get your thumb onthat left stick and leave it there! Forceyourself to go back and re-read myarticle on “Balance, and Hang Tail andReturn to Balance and Trim”, then startlooking for lift, leading with yourmodel’s rudder. You paid for yourwhole radio. Start using it.

Finding the Core

When your model indicates lift, don’tjust stop and turn, search the shapeand edges of that thermal. Doing sowill tell you which direction it’smoving or if it’s moving at all. Thatmeans taking a few seconds to fly flatand straight till your model getssluggish, then turning 90 to see what’sover that way. Once you feel that youhave ‘felt’ it out, then dig back into thecore area.

Use ALL of your Radio!

Once in lift, get to work with switchesand levers. Since you paid for yourtrim levers it’s silly to just set them andthen let them rust in place. They getlonely and need lots of attention just asboth control sticks do.

One question I always ask a pilot I amtiming for is, “Wouldn’t you ratheryour plane was falling upwardsinstead of downwards while in ther-mal turns?” Too often guys are doing abow-tie pattern of circling becausethey don’t take advantage of theirelevator trim lever. Why not crank insome up trim when you hit lift, thencontrol your model’s nose by workingin the needed down stick to keep your

plane from slowing too much, but allthe time working up?

Camber too! There’s never a bettertime to dirty your plane up with abouta 1/8” of full trailing edge camber thanwhen you are in lift. Like I said, justwatch the nose to keep your planemoving along, instead of porpoising.

You’ll be surprised how you suddenlystart adding a minute to every flight!

When it’s time to head down for yourlanding approach, take that added uptrim and camber out. In fact, add aclick of down trim in for landings; it’sa lot easier to fly through a groundthermal than it is to correct for asurprise nose pop up on approach.

Lift is:

Energy, same as jet fuel. With it yourmodel is active, responsive, nimble,perky, quick and FUN.

Sink is:

Iron poor blood, sloth-y, un-respon-sive, weird acting, tail hang-y, stall-y,slow, up for sale.

A Final Tip

You know you have found lift whenyour model tells you. IF you have yourmodel balanced for flying versus somemisguided lead filled nose idea that amodel is ‘more stable’ when it has asnoot full of lead, its tail can pop upwhen the slightest amount of lift blastsup under its tail. But even with aperfectly balanced model, YOU needto be watching for that invisible risingenergy that will super charge yourcontrols (go back and read my articleon “The Hunt”).

That means as you fly along you can’tjust sit there and hope lift hits you onthe noggin; you have to be looking andtesting all the way away, bumpingrudder to see if there is a response.

What happens if your rudder doesn’tseem to do much on YOUR model?Your expert friends would advise youto install a bigger rudder, but don’t!It’s the lead in the nose that stops yourrudder from having the strength tomove your plane’s nose. Get yourmodel balanced, reduce your controlthrows to settle the improved reaction,and watch your plane tell you the “TenTips That You Have Found Lift!”

See you next trip!

n

Page 19April 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

Full Size Announcement& R/C Invitation

2003 Eastern WorkshopFriday, June 20 through Sunday, June 22

Ridgely Airpark, on Maryland’s Eastern Shore.

At this year’s workshop the emphasis will be on flying, sharing sailplane-building experiences andtechniques, and just hanging out together. We will have a few technical presenters and as many kit-providers and builders as we can muster, but there will be more time for flying and talking withfriends. Come with plans and bits and pieces of what you’re working on—or a flyable finishedproduct: just let us know what you’re bringing. Please return the tear-off portion of this notice asdirected below.

Ridgely Airpark: (1N0) Location, 2 miles NE of the town of Ridgely, MD. Coordinates: N38-58.21,W075-51.98. Tel: 410-634-2806, hours 8am-dusk daily. Elevation 63. Pattern altitude 1045 MSL (allaircraft). Runway: 12-30 2710x95, turf; lights, PCL; obstruction, trees rwy 30. Approaches: (VFR). FSS:Leesburg 800-992-7433. Frequencies: UNICOM 122.8; CTAF 122.6. Charts: Washington sectional.Notes: parachuting.

Lodging (there is camping at the airfield: please prearrange with us):Slo Horse Inn 1649 Holly Road, Greensboro, MD (10 min to arpt) 410-634-2128Riverside Hotel N. Main St., Greensboro, MD (15 min) 410-482-7100White Pillars Inn 206 S. Fifth Ave., Denton, MD (15 min) 410-479-3292Queenstown Inn 7109 Main St., Queenstown, MD (20 min) 888-744-3407Holiday Inn Expr. 1020 Kent Narrows Rd., Grasonville, MD (20 min) 800-465-4329Comfort Inn 3101 Main St., Grasonville, MD (20 min) 800-228-5150Sleep Inn US 301/50, 101 VFW Ave., Grasonville, MD (20 min) 800-753-3746Econo Lodge 81175 Ocean Gateway, Easton, MD (25 min) 800-553-2666Holiday Inn Expr. 8561 Ocean Gateway, Easton, MD (25 min) 800-465-4329Days Inn 7018 Ocean Gateway, Easton, MD (25 min) 800-329-7466Comfort Inn 8523 Ocean Gateway, Easton, MD (25 min) 800-228-5150

For information contact: Dave Hudnut, 610-584-6691 (dhudnut@juno.com),Al McCarty, 215-453-7602 (almccarty@easy-pages.com), orTom Blevins, 207-882-6396 (tomblevins@gwi.net).

fee: Pre-registration (til June 10):member & family $25 (meal costs not included)non-member & family $30

Registration at the door:member & family $35 individual, one day: $17.50non-member & family $40

____________________________________________________________________________________Make check payable to Sailplane Homebuilders Association (by June 10). Send to: Dave Hudnut, 951 Harleysville Pike, Schwenksville, PA 19473

Name:_________________________________ phone:___________________

address:_______________________________ e-mail:___________________

______________________________________ member of (circle): SHA, SSA, VSA

I’ll be bring my sailplane [ ] Yes [ ] No Type ________________________________