Art Hale Ventura California put Fox 2-powerea i-eather Merchant floats Dont use downthrust its down-elevator-like effect big stab keeps model high speed water making takeoffs difficult Feather Merchant 72 YOU remember provided youre certain age old Lil Abner comic strips Feather Merchants funny little fellows long black coats tall black hats bane Pappy Yokums existencealways trying steal Presarved Turnips secretly made woods beyond view Mammy Yokum succeeded often happeneda personally affronted Pappy would chase shootin iron much result Snuffy Smith strip featured same cameo Remember Snuffy chasing Revenoors confiscating moonshine did happen name model after Pappy Yokums persecutors early days Gas model flying belonged San Antonio Gas Model Airplane Association SAGMAA did quite well competition 1938 1942 attended meets together over Texas Arriving Austin meet morning overheard someone quip Well Feather Merchants coming steal Presarved Turnips Before long Id clapped name onto Bantam-powered original Id good results during 1940 1941 contest seasons Id flown model both competition fun given new covering job second year During period broke three props airplane prop broke after long flight during funsie session Kelly Field club flying site plane escaping both Kellys boundaries lift glided over area filled mesquite trees pear cactus rattlesnakes ended up middle clearing struck solitary mesquite tree just above ground level Only prop broke truly justice world dont fly over pigeons sometimes model came call Feather Merchant traces its origins Cavalier built standard Berkeley kit 1938 Id put together enough pocket money buy kit powered finished plane Brown B Id gotten Christmas Cavalier didnt last long Despite its generous downthrust model made loop takeoff crashed Except wing creamed Next built Lackey Zenith flew like dream wasnt winning anything So came up own design Goon 60% stabilizer radical its day models rate climb however too low time-limited engine run events dominated famous Goldberg Zipper meantime Id become big boyslike Charley Adams Richard Sherman Fred Cordova et alwhom Id idolized just few years before achieving successes rubber designs together ballooning interest aerodynamics got thinking about Berkeley Cavalier model such lemon downthrust effect peers couldnt help except too found uary 1993 23 Old-Timer Flies Anew RC Assist nothing nice say about model fact Berkeley apparently discouraged soon stopped making kit decided build new model using Cavalier wing Money scarce needed salvage whatever could misadventure Model aeronautics game cant blame Ozzie Reynoldss ideas about size scale effect although theories play significant role Theories relating full-scale aerodynamics must modified using both modeling experience hunches Around time designing model Cavalier wing somehow managed have reports aerodynamics mailed NACA now NASA Though partly understood what read correlating modeling experience helped make sense Kutta-Joukowski theory lift completely fascinated Remembering Cavalier its short tail moment arm nearly midfuselage wing great downthrust nose-up instability could guess design hadnt worked Maybe trim right low speed increased airspeed generated strong nose-up moment Maybe much-strengthened downwash wing struck stabilizer mostly its upper surface decreasing stabs angle attack until lifted down looked answers latest design model narrow body belly low center-of-lateral area long tail moment large stab set positive incidence placed wing top cabin fuselage set 20 incidence stab kept conventional Mr Buckmaster Mr Tileson please note refrained using word decalage sake friendly relations using generous dihedral washout tips kept Cardinals excessive downthrustfor reason just discovered high school trigonometry sine tangent angles less 50 virtually equal close zero Therefore downthrust imposes downward force nearly zero making its name improper diverts downwash wing upward direction really made points teacher Mrs Wimberley checked out theory release models airspeed zero propwash strikes large stab Since stab positive angle incidencesay 1 0—and propwash diverted upward 50 good portion stab effectively 60 angle attack hence provides lift As airspeed increases wing lift downwash combination downflow upflow propwash decreases angle attack affected stab area reducing down-elevator-like effect felt sure because recalled way rubber jobs gliders lifted tails strong liftdiving stalling diving again yet still gaining altitude course sometimes model would spiral way down low tip remained stall sure Kutta Joukowski would have approved theory Too tried idea Goon late 1938 could hope right amount stab incidence downthrust Apparently did model flew very well wanted try couple other ideas required money teenagers business acumen sold new plane spectator five bucks Though hadnt included engine Dad disgusted What does know thought just bought Baby Cyclone Cless tank coil condenserfor two bucks five bucks jeans rich spent last months 1939 designing testing Hum-Dinger flew right off drawing board made several flights sheer ecstasy drinking praise about climb glide engine cut takeoff model stalled made nice recovery about three feet above ground Sharing space other side Kelly runway headlight Model Both parties demolished empennage untouched Model owner quite civil said should have moved car started flying models its direction heart broken five-buck fortune long gone Id put dollar Moore prop model instead reworked 25-cent Modelcraft used fun-flying model almost identical Id designed Cavalier wing Because didnt enjoy plotting Eiffel 431 ribs made rib spacing fairly wide prevent covering sagging forward part upper camber Id used 1/ x -in multispars upper lower strip main rear spars would normally have stiffen spars used poster board webbing between ribs produced very strong lightweight wing Incidentally hadnt used multispars provide turbulators forward part upper airfoil method improving airfoil performance yet invented 24 Model Aviation hard Allen Urunga NSW Australia uses 05 26 Surpass FM 72 says flies well though lost wing tip washout Merrilyn Borthwick Chapel Hill OLD Australia wife Airborne Magazines famous columnist Cohn Borthwick Feather Merchant 80 author says planes engine appears either Orwick Anderson Spitfire bottom longerons cemented together point some distance behind rectangular fuselage cross section curving fuselage downward auto matically gave stabilizer little over degree positive incidence Again provided excessive washout tips used generous dihedral model climbed engine cutoff fairly tight quite steep left spiral made nice glide transition wing leveled right glide circle started airplanes life short never called anything except Brown job After talking parents Bantam 19 Christmas 1940 scaled down Brown job 46-inch span Well almost scale also widened chord bit decreased aspect ratio Class model dubbed Feather Merchant Today has SAM Society Antique Modelers OldTimer approval Feather Merchant 46 does original version Feather Merchant 72 featured article 1980 scaled up 46-incher 80 inches SAM RC Assist version will handle 60 ignition engine has since scaled down several sizes SAM approval Feather Merchant 72 FF RC Assist 653-sq-in wing area maximum glow engine 29 weight 45 oz Feather Merchant 46 FF RC Assist wing area 288 sq maximum glow engine 12 weight 20 oz Feather Merchant 80 RC Assist wing area 864 sq maximum glow engine 38 Fox 36 engine displace ment closest 38 weight 60 oz Feather Merchant 56 RC Assist scaled especially Ohlsson 23 event wing area 429 sq maximum glow engine 19 weight 30 oz weights based wing loading 10 oz/sq ft first three Feather Merchants kitted small runs US Germany Michael Volz Modellbau manufactured Feather Merchant 72 distributed kit model has built flown over world its pleasing get letters some builders accompanying photographs show work Bill Forrey Contributing Editor Model Builder won 1984 10th annual Astro Champs electric-powered Feather Merchant 72 published kit review April issue Model Builder have experience assembling builtfrom-sticks models can build Feather Merchant construction notes below point out possible trouble areas suggest ways making job easier Incidentally use CyA cyanoacrylate glues almost exclusively Construction Fuselage Build sides first crafting both same time splitting apart razor blade Cover plan clear plastic backing used rolls MonoKote youre using CyA glues try bend bottom longerons * February 1993 25 Muriel Oglesby Mountain View California learned fly 0S 25-powered Feather Merchant 72 Muriels husband Richard built Author Lehmberg three four Feather Merchant versions left right 72 46 80 Good fliers wide stall tolerance Feather Merchants have SAM Society Antique Modelers Old-Timer approval FUSELAGE VIEW 5/I TAIL OjND 0* P510*50 NO SNOWSTRUE SANE RIOSSEOS POOW /1___ ~T 1i~ND* I [1 P3FRF54IooON NINNOLOWOOUNO m Fl00ONNDON onF 0NOSNDLIN&LANW FRTONEROC000 LAND RG GEAR bETA IF N ERN TO ONES NOOSO E WEt S OSLO CR0000*_____ III WIRDo50lI NDFUSELAGE VIEW SOLON NUONUTO jaoaOLOO EEDE ZIAWZEZZIWZV10 POND 00509 ND MODEL AVIATION FEATHER MERCHANT T2 INTO NEONDE 00 FOEN LEORROTO [J~LOpIY3pENEECp 0 SN PT 0 o poND WING JOINER dry Instead soak part longerons youll bending using either water waterand-ammonia glass cleaner last two methods will quicker longe rons place dry alcohol hair dryer Add planking shown plan point should have two fuselage sides top longerons flapping about Block up sides side flat table install crosspieces same length Constantly check square ensure top side precisely above flat table Lay assembly aside Make turtledeck formers Feather Merchant 46 Feather Merchant 80 use sheet formers other versions use builtup formers prefer build up formers since eliminates cutting holes control rods produces lighter result Cut crosspieces bridge sides beneath formers Also cut few crosspieces remain fitted bottom Finish joining two sides Bring together rear wrap rubberband Beginning bottom install first crosspiece estimate cut bevels required cement piece place Continue until top bottom crosspieces have installed Keep checking alignment go error will permanent create built-in turn generally because pigeon effect direction dont want Pinch bottom longerons together clothespins cement place Sand away vee bottom longerons using sanding block Glue formers followed flapping longerons stringers Complete nose shown plan Make landing gear lace firewall wire Load assembly baking soda saturate CyA prefer use commercial engine mounts bolted firewall rather wooden engine bearers since makes lot easier change engines necessary Install poster board shown plan prefer cover nose window areas poster board using white silver light gray Monotrim simulate win dows Dont forget wing hold-down dowels gussets Building stabilizer basically conven tional working plan includes reed piece doesnt have wet bending Because its opposite curvature will bend covering tightens Install leading edges trailing edges tips Add rib bottoms spars rib tops Build stabilizer elevator piece cutting unit apart after sanding has completed Cap adjoining rib/elevator spars top bottom between ribs procedure fin rudder much same except since no flat bottom ribs attached structure off work surface Builders call air Shim up trailing edge amount indicated pin weigh down build 26 Model Aviation scher Dowling built FM 46 flown 12A Texaco sure looks like Seguin Texas site background Bob Nolan Dunedin Florida pulls free flight version Ohisson Gold Seal Model red silk black trim Three View Page 96 Full-Size Plans Available Page 176 LEFT WING PLAN 808T88800808118008 10080180 0018T 801 ooo OPboa 30008T0 RIBS 8 -00U8L08Too 88000888180Th 0008818008 TOIS 0008 TO 0010080000 OP TOOS SlOE OP 80000 8808 0888 TO 8008 8000 8 00 88018 RIGHT WING PLAN ___________________II TOP 8 0000800 8188 83 tO80880 00 8080000 80088 Top 00 00080T 01008000 8800 8808 TIP 0808100880080800800__________________________________ 808088088 P0888888808088080 888080180000 8008 810880800018 08 80080 ____RA1080800 0 0 0888800888888888008881880000008 800008 08088 80088 R7__0180108888088081080 00008 88881 COP 18 088 808810888 80818088 00 8a08800 8808 800 0088808 118 008 88081 808 8808888 ft.4088 10 00080 00l808 088100 101880050088808801000108 80010088 808000080 S STA8ILI ER I000 81188 0080000 8 1 80 00 8 8 8188 008 00000000100 800008 08Ro1Oo 00000ELEV / I~ MODEL AVIATION FEAThER MERCHANT 72 800080808000 00 8008 Bill Forrey Model Builders sailplane columnist won 10th annual Astra Champs Feather Merchant 72 Electric wing tip washout shown plan Dont try omit washout reduce dihedral Theyre good reason0 youd unhappy Dont forget spar webbing multispar versions Either conventional sparring multispar construction works satisfactorily 46- 72-inch versions used both types like better covering appearance conventional sparring permits dont think possible turbu lator effect multispars particularly Type Sport Wingspan 72 inches Recommended engine size type 29 cu smaller glow ignition Number RC channels recommended Three Expected flying weight 45 ounces Type construction Built-up Type covering/finish recommended Iron-on films silkand-dope effective other hand multispars easy quick light Either type provides good covering contact bottom preserve undercamber Feather Merchants easy fly Keep mind however dont like high speed level flight youre using radio control0 dont expect lose altitude landing approach giving down elevator airplanes low drag high lift prevent releasing stick0 youll find yourself nearly Continued page 127 February 1993 27 Charles St info & directions call Dr Sandy Frank 817-599-7131 Sponsor WEATHERFORD AERO MODELING SOCIETY FL APR 3Fort Myers FL El 2nd Annual Swap Shop & Auction 900 am -400 pm 800 am Sellers Corkscrew Woodlands Esif 19 W off 75 Corkscrew Rd 1/4 M 75 Larger Hall Tables $10 Advance Reservations Definitely Recommended Admission $2 Paul Barfos 1002 Washington Ave Lehigh FL 33936 PH 813-368-0214 Sponsor SW FLORIDA AERO CLUB LISTING AD INFORMATION NORMAL LISTING AMA sanction issued event event will listed automatically Contest Calendar section listing will give date place name eventplus competition events flying site Contest Director name address Use Supplementary paid Ad space suggested description unusual special events deviations AMA rules significant aspects meet Paid ads may helpful promoting funfly-type meets give directions flying site SUPPLEMENTARY ADS Larger ads can inserted Contest Calendar section paying fee ads accepted AMA-sanctioned events FEE Fees based ad size whether sponsor AMAchartered club AD POLICY SIZE 1/s-in wide either /4 1/2 2/4-in high full size ad appears Contest Calendar section PRICING 3/4$8 1/2$16 2/4$24 time ad run payable advance AMA-chartered clubs pay half rate AD PREPARATION advertiser must prepare Supplementary Ad Ads must full size see above Ads made up dark black white background will reproduce well recommended ad made heavy paper lightweight cardboard PLEASE DO NOT USE PHOTOGRAPHS ON ADS SUBMITTAL DEADLINE effort will made include Supplementary Ads received 14th month issue reaching readers approximately fourth week following month However cannot guaranteed ads published space-available basis normally two-month lead time required inserting Supplementary Ad same deadline will apply sanctioned events listings Questions about either Supplementary Ads regular Sanctioned Events listings should directed Debbie Brown AMAs Competition Department Send ads AMA HO Attention Competition Dept Renew 93 Built FlewlLehman Continued page 20 tempera paints later covered engine area clear dope should also mention tops bottoms fuselages midwing sheeted areas covered classroom tablet backings As project neared completion put several hours covering wings installing hardware radio engine maiden flight Pan Am took place evening April 16 Uncertain outcome made arrangements student present Joshua Smucker young man likely become pilot accompanied full throttle airliner sluggish fresh spring grass did take off fly nicely Unfortunately covering wing began loosen after two laps bring down remarked handy have throttle control cases like too dark repairs second flight Joshua went out again three evenings later time went extremely well Joshua outside circle throttle did takeoffs touch-and-goes slow approaches Communication hand signal week later April 23 students built Pan Am took turns being copilot enjoyed immensely After safety lesson person took turn throttle control about five laps before handing transmitter next pilot Later transferred engine radio Swissair second class its session Both classes preferred high-speed flight after deliberating beauty slow planned approaches gentle flybys persisted flying full tilt Throughout sessions however no matter what kids did throttle planes handled well enriching enjoy able venture kids made sure knew highlight school year Its too bad well probably never know what effect experience futures youngsters Wouldnt neat least came across article 20 30 years now wrote letter editor her/Lehmberg Continued page 27 same altitudethough lot closer little up stick will drop tail increase sink releasing stick will give nice touchdown Like Feather Merchants 72-inch version has wide stall tolerance stalled still mushes along instead pitching down can exploit tight turns glide using some up elevator strong rudder Oh yesI almost forgot Dont think ailerons Feather Merchant want everyone builds Feather Merchant have ball would like picturemaybe have questions problems like drop line 21337 Oak Park Lane Anderson CA 96007 An SASE would appreciated remember reading somewhere closing seems appropriate See ya Chicken House yhear /doBolt Continued page 30 Im going break off discussion point remainder fairly lengthy Save portion continuity reference study concluding part Part Two will cover process developing force arrangements model get ultimate flight performance Ill also talk about trimming methods continued lectricslKopski Continued page 76 fancy wiring harness incorporating double-pole double-throw center-off DPDTCO DP on-off-on switch associated wiring also requires battery made up two half-packs having same cell count cell type idea behind scheme use two packs connected series high power same two packs connected parallel cruise power connection accomplished servo-driven switch described above Thus in-flight switching between two available voltage levelsand off wellis readily accomplished Andjust theres no misunderstanding cells arrangement charged senes Ni-Cds never charged parallel wiring diagram gives details actual use plane motor prop configured cruise climb slightly voltage available paralleled half-packs half voltage higher voltage associated cells series results relatively aggressive climb capability needed center-off switch option allows charge conservation during thermaling Since much total flight time likely occur cruise power levels battery efficiency during periods considerable interest argued parallel-connected half-packs afford increased efficiency since half nominally operating half total motor current Cells tend display somewhat higher capacity lower drain rates conversely somewhat lower capacity higher currents February 1993 127 II
Edition: Model Aviation - 1993/02
Page Numbers: 23, 24, 25, 26, 27, 127
Art Hale Ventura California put Fox 2-powerea i-eather Merchant floats Dont use downthrust its down-elevator-like effect big stab keeps model high speed water making takeoffs difficult Feather Merchant 72 YOU remember provided youre certain age old Lil Abner comic strips Feather Merchants funny little fellows long black coats tall black hats bane Pappy Yokums existencealways trying steal Presarved Turnips secretly made woods beyond view Mammy Yokum succeeded often happeneda personally affronted Pappy would chase shootin iron much result Snuffy Smith strip featured same cameo Remember Snuffy chasing Revenoors confiscating moonshine did happen name model after Pappy Yokums persecutors early days Gas model flying belonged San Antonio Gas Model Airplane Association SAGMAA did quite well competition 1938 1942 attended meets together over Texas Arriving Austin meet morning overheard someone quip Well Feather Merchants coming steal Presarved Turnips Before long Id clapped name onto Bantam-powered original Id good results during 1940 1941 contest seasons Id flown model both competition fun given new covering job second year During period broke three props airplane prop broke after long flight during funsie session Kelly Field club flying site plane escaping both Kellys boundaries lift glided over area filled mesquite trees pear cactus rattlesnakes ended up middle clearing struck solitary mesquite tree just above ground level Only prop broke truly justice world dont fly over pigeons sometimes model came call Feather Merchant traces its origins Cavalier built standard Berkeley kit 1938 Id put together enough pocket money buy kit powered finished plane Brown B Id gotten Christmas Cavalier didnt last long Despite its generous downthrust model made loop takeoff crashed Except wing creamed Next built Lackey Zenith flew like dream wasnt winning anything So came up own design Goon 60% stabilizer radical its day models rate climb however too low time-limited engine run events dominated famous Goldberg Zipper meantime Id become big boyslike Charley Adams Richard Sherman Fred Cordova et alwhom Id idolized just few years before achieving successes rubber designs together ballooning interest aerodynamics got thinking about Berkeley Cavalier model such lemon downthrust effect peers couldnt help except too found uary 1993 23 Old-Timer Flies Anew RC Assist nothing nice say about model fact Berkeley apparently discouraged soon stopped making kit decided build new model using Cavalier wing Money scarce needed salvage whatever could misadventure Model aeronautics game cant blame Ozzie Reynoldss ideas about size scale effect although theories play significant role Theories relating full-scale aerodynamics must modified using both modeling experience hunches Around time designing model Cavalier wing somehow managed have reports aerodynamics mailed NACA now NASA Though partly understood what read correlating modeling experience helped make sense Kutta-Joukowski theory lift completely fascinated Remembering Cavalier its short tail moment arm nearly midfuselage wing great downthrust nose-up instability could guess design hadnt worked Maybe trim right low speed increased airspeed generated strong nose-up moment Maybe much-strengthened downwash wing struck stabilizer mostly its upper surface decreasing stabs angle attack until lifted down looked answers latest design model narrow body belly low center-of-lateral area long tail moment large stab set positive incidence placed wing top cabin fuselage set 20 incidence stab kept conventional Mr Buckmaster Mr Tileson please note refrained using word decalage sake friendly relations using generous dihedral washout tips kept Cardinals excessive downthrustfor reason just discovered high school trigonometry sine tangent angles less 50 virtually equal close zero Therefore downthrust imposes downward force nearly zero making its name improper diverts downwash wing upward direction really made points teacher Mrs Wimberley checked out theory release models airspeed zero propwash strikes large stab Since stab positive angle incidencesay 1 0—and propwash diverted upward 50 good portion stab effectively 60 angle attack hence provides lift As airspeed increases wing lift downwash combination downflow upflow propwash decreases angle attack affected stab area reducing down-elevator-like effect felt sure because recalled way rubber jobs gliders lifted tails strong liftdiving stalling diving again yet still gaining altitude course sometimes model would spiral way down low tip remained stall sure Kutta Joukowski would have approved theory Too tried idea Goon late 1938 could hope right amount stab incidence downthrust Apparently did model flew very well wanted try couple other ideas required money teenagers business acumen sold new plane spectator five bucks Though hadnt included engine Dad disgusted What does know thought just bought Baby Cyclone Cless tank coil condenserfor two bucks five bucks jeans rich spent last months 1939 designing testing Hum-Dinger flew right off drawing board made several flights sheer ecstasy drinking praise about climb glide engine cut takeoff model stalled made nice recovery about three feet above ground Sharing space other side Kelly runway headlight Model Both parties demolished empennage untouched Model owner quite civil said should have moved car started flying models its direction heart broken five-buck fortune long gone Id put dollar Moore prop model instead reworked 25-cent Modelcraft used fun-flying model almost identical Id designed Cavalier wing Because didnt enjoy plotting Eiffel 431 ribs made rib spacing fairly wide prevent covering sagging forward part upper camber Id used 1/ x -in multispars upper lower strip main rear spars would normally have stiffen spars used poster board webbing between ribs produced very strong lightweight wing Incidentally hadnt used multispars provide turbulators forward part upper airfoil method improving airfoil performance yet invented 24 Model Aviation hard Allen Urunga NSW Australia uses 05 26 Surpass FM 72 says flies well though lost wing tip washout Merrilyn Borthwick Chapel Hill OLD Australia wife Airborne Magazines famous columnist Cohn Borthwick Feather Merchant 80 author says planes engine appears either Orwick Anderson Spitfire bottom longerons cemented together point some distance behind rectangular fuselage cross section curving fuselage downward auto matically gave stabilizer little over degree positive incidence Again provided excessive washout tips used generous dihedral model climbed engine cutoff fairly tight quite steep left spiral made nice glide transition wing leveled right glide circle started airplanes life short never called anything except Brown job After talking parents Bantam 19 Christmas 1940 scaled down Brown job 46-inch span Well almost scale also widened chord bit decreased aspect ratio Class model dubbed Feather Merchant Today has SAM Society Antique Modelers OldTimer approval Feather Merchant 46 does original version Feather Merchant 72 featured article 1980 scaled up 46-incher 80 inches SAM RC Assist version will handle 60 ignition engine has since scaled down several sizes SAM approval Feather Merchant 72 FF RC Assist 653-sq-in wing area maximum glow engine 29 weight 45 oz Feather Merchant 46 FF RC Assist wing area 288 sq maximum glow engine 12 weight 20 oz Feather Merchant 80 RC Assist wing area 864 sq maximum glow engine 38 Fox 36 engine displace ment closest 38 weight 60 oz Feather Merchant 56 RC Assist scaled especially Ohlsson 23 event wing area 429 sq maximum glow engine 19 weight 30 oz weights based wing loading 10 oz/sq ft first three Feather Merchants kitted small runs US Germany Michael Volz Modellbau manufactured Feather Merchant 72 distributed kit model has built flown over world its pleasing get letters some builders accompanying photographs show work Bill Forrey Contributing Editor Model Builder won 1984 10th annual Astro Champs electric-powered Feather Merchant 72 published kit review April issue Model Builder have experience assembling builtfrom-sticks models can build Feather Merchant construction notes below point out possible trouble areas suggest ways making job easier Incidentally use CyA cyanoacrylate glues almost exclusively Construction Fuselage Build sides first crafting both same time splitting apart razor blade Cover plan clear plastic backing used rolls MonoKote youre using CyA glues try bend bottom longerons * February 1993 25 Muriel Oglesby Mountain View California learned fly 0S 25-powered Feather Merchant 72 Muriels husband Richard built Author Lehmberg three four Feather Merchant versions left right 72 46 80 Good fliers wide stall tolerance Feather Merchants have SAM Society Antique Modelers Old-Timer approval FUSELAGE VIEW 5/I TAIL OjND 0* P510*50 NO SNOWSTRUE SANE RIOSSEOS POOW /1___ ~T 1i~ND* I [1 P3FRF54IooON NINNOLOWOOUNO m Fl00ONNDON onF 0NOSNDLIN&LANW FRTONEROC000 LAND RG GEAR bETA IF N ERN TO ONES NOOSO E WEt S OSLO CR0000*_____ III WIRDo50lI NDFUSELAGE VIEW SOLON NUONUTO jaoaOLOO EEDE ZIAWZEZZIWZV10 POND 00509 ND MODEL AVIATION FEATHER MERCHANT T2 INTO NEONDE 00 FOEN LEORROTO [J~LOpIY3pENEECp 0 SN PT 0 o poND WING JOINER dry Instead soak part longerons youll bending using either water waterand-ammonia glass cleaner last two methods will quicker longe rons place dry alcohol hair dryer Add planking shown plan point should have two fuselage sides top longerons flapping about Block up sides side flat table install crosspieces same length Constantly check square ensure top side precisely above flat table Lay assembly aside Make turtledeck formers Feather Merchant 46 Feather Merchant 80 use sheet formers other versions use builtup formers prefer build up formers since eliminates cutting holes control rods produces lighter result Cut crosspieces bridge sides beneath formers Also cut few crosspieces remain fitted bottom Finish joining two sides Bring together rear wrap rubberband Beginning bottom install first crosspiece estimate cut bevels required cement piece place Continue until top bottom crosspieces have installed Keep checking alignment go error will permanent create built-in turn generally because pigeon effect direction dont want Pinch bottom longerons together clothespins cement place Sand away vee bottom longerons using sanding block Glue formers followed flapping longerons stringers Complete nose shown plan Make landing gear lace firewall wire Load assembly baking soda saturate CyA prefer use commercial engine mounts bolted firewall rather wooden engine bearers since makes lot easier change engines necessary Install poster board shown plan prefer cover nose window areas poster board using white silver light gray Monotrim simulate win dows Dont forget wing hold-down dowels gussets Building stabilizer basically conven tional working plan includes reed piece doesnt have wet bending Because its opposite curvature will bend covering tightens Install leading edges trailing edges tips Add rib bottoms spars rib tops Build stabilizer elevator piece cutting unit apart after sanding has completed Cap adjoining rib/elevator spars top bottom between ribs procedure fin rudder much same except since no flat bottom ribs attached structure off work surface Builders call air Shim up trailing edge amount indicated pin weigh down build 26 Model Aviation scher Dowling built FM 46 flown 12A Texaco sure looks like Seguin Texas site background Bob Nolan Dunedin Florida pulls free flight version Ohisson Gold Seal Model red silk black trim Three View Page 96 Full-Size Plans Available Page 176 LEFT WING PLAN 808T88800808118008 10080180 0018T 801 ooo OPboa 30008T0 RIBS 8 -00U8L08Too 88000888180Th 0008818008 TOIS 0008 TO 0010080000 OP TOOS SlOE OP 80000 8808 0888 TO 8008 8000 8 00 88018 RIGHT WING PLAN ___________________II TOP 8 0000800 8188 83 tO80880 00 8080000 80088 Top 00 00080T 01008000 8800 8808 TIP 0808100880080800800__________________________________ 808088088 P0888888808088080 888080180000 8008 810880800018 08 80080 ____RA1080800 0 0 0888800888888888008881880000008 800008 08088 80088 R7__0180108888088081080 00008 88881 COP 18 088 808810888 80818088 00 8a08800 8808 800 0088808 118 008 88081 808 8808888 ft.4088 10 00080 00l808 088100 101880050088808801000108 80010088 808000080 S STA8ILI ER I000 81188 0080000 8 1 80 00 8 8 8188 008 00000000100 800008 08Ro1Oo 00000ELEV / I~ MODEL AVIATION FEAThER MERCHANT 72 800080808000 00 8008 Bill Forrey Model Builders sailplane columnist won 10th annual Astra Champs Feather Merchant 72 Electric wing tip washout shown plan Dont try omit washout reduce dihedral Theyre good reason0 youd unhappy Dont forget spar webbing multispar versions Either conventional sparring multispar construction works satisfactorily 46- 72-inch versions used both types like better covering appearance conventional sparring permits dont think possible turbu lator effect multispars particularly Type Sport Wingspan 72 inches Recommended engine size type 29 cu smaller glow ignition Number RC channels recommended Three Expected flying weight 45 ounces Type construction Built-up Type covering/finish recommended Iron-on films silkand-dope effective other hand multispars easy quick light Either type provides good covering contact bottom preserve undercamber Feather Merchants easy fly Keep mind however dont like high speed level flight youre using radio control0 dont expect lose altitude landing approach giving down elevator airplanes low drag high lift prevent releasing stick0 youll find yourself nearly Continued page 127 February 1993 27 Charles St info & directions call Dr Sandy Frank 817-599-7131 Sponsor WEATHERFORD AERO MODELING SOCIETY FL APR 3Fort Myers FL El 2nd Annual Swap Shop & Auction 900 am -400 pm 800 am Sellers Corkscrew Woodlands Esif 19 W off 75 Corkscrew Rd 1/4 M 75 Larger Hall Tables $10 Advance Reservations Definitely Recommended Admission $2 Paul Barfos 1002 Washington Ave Lehigh FL 33936 PH 813-368-0214 Sponsor SW FLORIDA AERO CLUB LISTING AD INFORMATION NORMAL LISTING AMA sanction issued event event will listed automatically Contest Calendar section listing will give date place name eventplus competition events flying site Contest Director name address Use Supplementary paid Ad space suggested description unusual special events deviations AMA rules significant aspects meet Paid ads may helpful promoting funfly-type meets give directions flying site SUPPLEMENTARY ADS Larger ads can inserted Contest Calendar section paying fee ads accepted AMA-sanctioned events FEE Fees based ad size whether sponsor AMAchartered club AD POLICY SIZE 1/s-in wide either /4 1/2 2/4-in high full size ad appears Contest Calendar section PRICING 3/4$8 1/2$16 2/4$24 time ad run payable advance AMA-chartered clubs pay half rate AD PREPARATION advertiser must prepare Supplementary Ad Ads must full size see above Ads made up dark black white background will reproduce well recommended ad made heavy paper lightweight cardboard PLEASE DO NOT USE PHOTOGRAPHS ON ADS SUBMITTAL DEADLINE effort will made include Supplementary Ads received 14th month issue reaching readers approximately fourth week following month However cannot guaranteed ads published space-available basis normally two-month lead time required inserting Supplementary Ad same deadline will apply sanctioned events listings Questions about either Supplementary Ads regular Sanctioned Events listings should directed Debbie Brown AMAs Competition Department Send ads AMA HO Attention Competition Dept Renew 93 Built FlewlLehman Continued page 20 tempera paints later covered engine area clear dope should also mention tops bottoms fuselages midwing sheeted areas covered classroom tablet backings As project neared completion put several hours covering wings installing hardware radio engine maiden flight Pan Am took place evening April 16 Uncertain outcome made arrangements student present Joshua Smucker young man likely become pilot accompanied full throttle airliner sluggish fresh spring grass did take off fly nicely Unfortunately covering wing began loosen after two laps bring down remarked handy have throttle control cases like too dark repairs second flight Joshua went out again three evenings later time went extremely well Joshua outside circle throttle did takeoffs touch-and-goes slow approaches Communication hand signal week later April 23 students built Pan Am took turns being copilot enjoyed immensely After safety lesson person took turn throttle control about five laps before handing transmitter next pilot Later transferred engine radio Swissair second class its session Both classes preferred high-speed flight after deliberating beauty slow planned approaches gentle flybys persisted flying full tilt Throughout sessions however no matter what kids did throttle planes handled well enriching enjoy able venture kids made sure knew highlight school year Its too bad well probably never know what effect experience futures youngsters Wouldnt neat least came across article 20 30 years now wrote letter editor her/Lehmberg Continued page 27 same altitudethough lot closer little up stick will drop tail increase sink releasing stick will give nice touchdown Like Feather Merchants 72-inch version has wide stall tolerance stalled still mushes along instead pitching down can exploit tight turns glide using some up elevator strong rudder Oh yesI almost forgot Dont think ailerons Feather Merchant want everyone builds Feather Merchant have ball would like picturemaybe have questions problems like drop line 21337 Oak Park Lane Anderson CA 96007 An SASE would appreciated remember reading somewhere closing seems appropriate See ya Chicken House yhear /doBolt Continued page 30 Im going break off discussion point remainder fairly lengthy Save portion continuity reference study concluding part Part Two will cover process developing force arrangements model get ultimate flight performance Ill also talk about trimming methods continued lectricslKopski Continued page 76 fancy wiring harness incorporating double-pole double-throw center-off DPDTCO DP on-off-on switch associated wiring also requires battery made up two half-packs having same cell count cell type idea behind scheme use two packs connected series high power same two packs connected parallel cruise power connection accomplished servo-driven switch described above Thus in-flight switching between two available voltage levelsand off wellis readily accomplished Andjust theres no misunderstanding cells arrangement charged senes Ni-Cds never charged parallel wiring diagram gives details actual use plane motor prop configured cruise climb slightly voltage available paralleled half-packs half voltage higher voltage associated cells series results relatively aggressive climb capability needed center-off switch option allows charge conservation during thermaling Since much total flight time likely occur cruise power levels battery efficiency during periods considerable interest argued parallel-connected half-packs afford increased efficiency since half nominally operating half total motor current Cells tend display somewhat higher capacity lower drain rates conversely somewhat lower capacity higher currents February 1993 127 II
Edition: Model Aviation - 1993/02
Page Numbers: 23, 24, 25, 26, 27, 127
Art Hale Ventura California put Fox 2-powerea i-eather Merchant floats Dont use downthrust its down-elevator-like effect big stab keeps model high speed water making takeoffs difficult Feather Merchant 72 YOU remember provided youre certain age old Lil Abner comic strips Feather Merchants funny little fellows long black coats tall black hats bane Pappy Yokums existencealways trying steal Presarved Turnips secretly made woods beyond view Mammy Yokum succeeded often happeneda personally affronted Pappy would chase shootin iron much result Snuffy Smith strip featured same cameo Remember Snuffy chasing Revenoors confiscating moonshine did happen name model after Pappy Yokums persecutors early days Gas model flying belonged San Antonio Gas Model Airplane Association SAGMAA did quite well competition 1938 1942 attended meets together over Texas Arriving Austin meet morning overheard someone quip Well Feather Merchants coming steal Presarved Turnips Before long Id clapped name onto Bantam-powered original Id good results during 1940 1941 contest seasons Id flown model both competition fun given new covering job second year During period broke three props airplane prop broke after long flight during funsie session Kelly Field club flying site plane escaping both Kellys boundaries lift glided over area filled mesquite trees pear cactus rattlesnakes ended up middle clearing struck solitary mesquite tree just above ground level Only prop broke truly justice world dont fly over pigeons sometimes model came call Feather Merchant traces its origins Cavalier built standard Berkeley kit 1938 Id put together enough pocket money buy kit powered finished plane Brown B Id gotten Christmas Cavalier didnt last long Despite its generous downthrust model made loop takeoff crashed Except wing creamed Next built Lackey Zenith flew like dream wasnt winning anything So came up own design Goon 60% stabilizer radical its day models rate climb however too low time-limited engine run events dominated famous Goldberg Zipper meantime Id become big boyslike Charley Adams Richard Sherman Fred Cordova et alwhom Id idolized just few years before achieving successes rubber designs together ballooning interest aerodynamics got thinking about Berkeley Cavalier model such lemon downthrust effect peers couldnt help except too found uary 1993 23 Old-Timer Flies Anew RC Assist nothing nice say about model fact Berkeley apparently discouraged soon stopped making kit decided build new model using Cavalier wing Money scarce needed salvage whatever could misadventure Model aeronautics game cant blame Ozzie Reynoldss ideas about size scale effect although theories play significant role Theories relating full-scale aerodynamics must modified using both modeling experience hunches Around time designing model Cavalier wing somehow managed have reports aerodynamics mailed NACA now NASA Though partly understood what read correlating modeling experience helped make sense Kutta-Joukowski theory lift completely fascinated Remembering Cavalier its short tail moment arm nearly midfuselage wing great downthrust nose-up instability could guess design hadnt worked Maybe trim right low speed increased airspeed generated strong nose-up moment Maybe much-strengthened downwash wing struck stabilizer mostly its upper surface decreasing stabs angle attack until lifted down looked answers latest design model narrow body belly low center-of-lateral area long tail moment large stab set positive incidence placed wing top cabin fuselage set 20 incidence stab kept conventional Mr Buckmaster Mr Tileson please note refrained using word decalage sake friendly relations using generous dihedral washout tips kept Cardinals excessive downthrustfor reason just discovered high school trigonometry sine tangent angles less 50 virtually equal close zero Therefore downthrust imposes downward force nearly zero making its name improper diverts downwash wing upward direction really made points teacher Mrs Wimberley checked out theory release models airspeed zero propwash strikes large stab Since stab positive angle incidencesay 1 0—and propwash diverted upward 50 good portion stab effectively 60 angle attack hence provides lift As airspeed increases wing lift downwash combination downflow upflow propwash decreases angle attack affected stab area reducing down-elevator-like effect felt sure because recalled way rubber jobs gliders lifted tails strong liftdiving stalling diving again yet still gaining altitude course sometimes model would spiral way down low tip remained stall sure Kutta Joukowski would have approved theory Too tried idea Goon late 1938 could hope right amount stab incidence downthrust Apparently did model flew very well wanted try couple other ideas required money teenagers business acumen sold new plane spectator five bucks Though hadnt included engine Dad disgusted What does know thought just bought Baby Cyclone Cless tank coil condenserfor two bucks five bucks jeans rich spent last months 1939 designing testing Hum-Dinger flew right off drawing board made several flights sheer ecstasy drinking praise about climb glide engine cut takeoff model stalled made nice recovery about three feet above ground Sharing space other side Kelly runway headlight Model Both parties demolished empennage untouched Model owner quite civil said should have moved car started flying models its direction heart broken five-buck fortune long gone Id put dollar Moore prop model instead reworked 25-cent Modelcraft used fun-flying model almost identical Id designed Cavalier wing Because didnt enjoy plotting Eiffel 431 ribs made rib spacing fairly wide prevent covering sagging forward part upper camber Id used 1/ x -in multispars upper lower strip main rear spars would normally have stiffen spars used poster board webbing between ribs produced very strong lightweight wing Incidentally hadnt used multispars provide turbulators forward part upper airfoil method improving airfoil performance yet invented 24 Model Aviation hard Allen Urunga NSW Australia uses 05 26 Surpass FM 72 says flies well though lost wing tip washout Merrilyn Borthwick Chapel Hill OLD Australia wife Airborne Magazines famous columnist Cohn Borthwick Feather Merchant 80 author says planes engine appears either Orwick Anderson Spitfire bottom longerons cemented together point some distance behind rectangular fuselage cross section curving fuselage downward auto matically gave stabilizer little over degree positive incidence Again provided excessive washout tips used generous dihedral model climbed engine cutoff fairly tight quite steep left spiral made nice glide transition wing leveled right glide circle started airplanes life short never called anything except Brown job After talking parents Bantam 19 Christmas 1940 scaled down Brown job 46-inch span Well almost scale also widened chord bit decreased aspect ratio Class model dubbed Feather Merchant Today has SAM Society Antique Modelers OldTimer approval Feather Merchant 46 does original version Feather Merchant 72 featured article 1980 scaled up 46-incher 80 inches SAM RC Assist version will handle 60 ignition engine has since scaled down several sizes SAM approval Feather Merchant 72 FF RC Assist 653-sq-in wing area maximum glow engine 29 weight 45 oz Feather Merchant 46 FF RC Assist wing area 288 sq maximum glow engine 12 weight 20 oz Feather Merchant 80 RC Assist wing area 864 sq maximum glow engine 38 Fox 36 engine displace ment closest 38 weight 60 oz Feather Merchant 56 RC Assist scaled especially Ohlsson 23 event wing area 429 sq maximum glow engine 19 weight 30 oz weights based wing loading 10 oz/sq ft first three Feather Merchants kitted small runs US Germany Michael Volz Modellbau manufactured Feather Merchant 72 distributed kit model has built flown over world its pleasing get letters some builders accompanying photographs show work Bill Forrey Contributing Editor Model Builder won 1984 10th annual Astro Champs electric-powered Feather Merchant 72 published kit review April issue Model Builder have experience assembling builtfrom-sticks models can build Feather Merchant construction notes below point out possible trouble areas suggest ways making job easier Incidentally use CyA cyanoacrylate glues almost exclusively Construction Fuselage Build sides first crafting both same time splitting apart razor blade Cover plan clear plastic backing used rolls MonoKote youre using CyA glues try bend bottom longerons * February 1993 25 Muriel Oglesby Mountain View California learned fly 0S 25-powered Feather Merchant 72 Muriels husband Richard built Author Lehmberg three four Feather Merchant versions left right 72 46 80 Good fliers wide stall tolerance Feather Merchants have SAM Society Antique Modelers Old-Timer approval FUSELAGE VIEW 5/I TAIL OjND 0* P510*50 NO SNOWSTRUE SANE RIOSSEOS POOW /1___ ~T 1i~ND* I [1 P3FRF54IooON NINNOLOWOOUNO m Fl00ONNDON onF 0NOSNDLIN&LANW FRTONEROC000 LAND RG GEAR bETA IF N ERN TO ONES NOOSO E WEt S OSLO CR0000*_____ III WIRDo50lI NDFUSELAGE VIEW SOLON NUONUTO jaoaOLOO EEDE ZIAWZEZZIWZV10 POND 00509 ND MODEL AVIATION FEATHER MERCHANT T2 INTO NEONDE 00 FOEN LEORROTO [J~LOpIY3pENEECp 0 SN PT 0 o poND WING JOINER dry Instead soak part longerons youll bending using either water waterand-ammonia glass cleaner last two methods will quicker longe rons place dry alcohol hair dryer Add planking shown plan point should have two fuselage sides top longerons flapping about Block up sides side flat table install crosspieces same length Constantly check square ensure top side precisely above flat table Lay assembly aside Make turtledeck formers Feather Merchant 46 Feather Merchant 80 use sheet formers other versions use builtup formers prefer build up formers since eliminates cutting holes control rods produces lighter result Cut crosspieces bridge sides beneath formers Also cut few crosspieces remain fitted bottom Finish joining two sides Bring together rear wrap rubberband Beginning bottom install first crosspiece estimate cut bevels required cement piece place Continue until top bottom crosspieces have installed Keep checking alignment go error will permanent create built-in turn generally because pigeon effect direction dont want Pinch bottom longerons together clothespins cement place Sand away vee bottom longerons using sanding block Glue formers followed flapping longerons stringers Complete nose shown plan Make landing gear lace firewall wire Load assembly baking soda saturate CyA prefer use commercial engine mounts bolted firewall rather wooden engine bearers since makes lot easier change engines necessary Install poster board shown plan prefer cover nose window areas poster board using white silver light gray Monotrim simulate win dows Dont forget wing hold-down dowels gussets Building stabilizer basically conven tional working plan includes reed piece doesnt have wet bending Because its opposite curvature will bend covering tightens Install leading edges trailing edges tips Add rib bottoms spars rib tops Build stabilizer elevator piece cutting unit apart after sanding has completed Cap adjoining rib/elevator spars top bottom between ribs procedure fin rudder much same except since no flat bottom ribs attached structure off work surface Builders call air Shim up trailing edge amount indicated pin weigh down build 26 Model Aviation scher Dowling built FM 46 flown 12A Texaco sure looks like Seguin Texas site background Bob Nolan Dunedin Florida pulls free flight version Ohisson Gold Seal Model red silk black trim Three View Page 96 Full-Size Plans Available Page 176 LEFT WING PLAN 808T88800808118008 10080180 0018T 801 ooo OPboa 30008T0 RIBS 8 -00U8L08Too 88000888180Th 0008818008 TOIS 0008 TO 0010080000 OP TOOS SlOE OP 80000 8808 0888 TO 8008 8000 8 00 88018 RIGHT WING PLAN ___________________II TOP 8 0000800 8188 83 tO80880 00 8080000 80088 Top 00 00080T 01008000 8800 8808 TIP 0808100880080800800__________________________________ 808088088 P0888888808088080 888080180000 8008 810880800018 08 80080 ____RA1080800 0 0 0888800888888888008881880000008 800008 08088 80088 R7__0180108888088081080 00008 88881 COP 18 088 808810888 80818088 00 8a08800 8808 800 0088808 118 008 88081 808 8808888 ft.4088 10 00080 00l808 088100 101880050088808801000108 80010088 808000080 S STA8ILI ER I000 81188 0080000 8 1 80 00 8 8 8188 008 00000000100 800008 08Ro1Oo 00000ELEV / I~ MODEL AVIATION FEAThER MERCHANT 72 800080808000 00 8008 Bill Forrey Model Builders sailplane columnist won 10th annual Astra Champs Feather Merchant 72 Electric wing tip washout shown plan Dont try omit washout reduce dihedral Theyre good reason0 youd unhappy Dont forget spar webbing multispar versions Either conventional sparring multispar construction works satisfactorily 46- 72-inch versions used both types like better covering appearance conventional sparring permits dont think possible turbu lator effect multispars particularly Type Sport Wingspan 72 inches Recommended engine size type 29 cu smaller glow ignition Number RC channels recommended Three Expected flying weight 45 ounces Type construction Built-up Type covering/finish recommended Iron-on films silkand-dope effective other hand multispars easy quick light Either type provides good covering contact bottom preserve undercamber Feather Merchants easy fly Keep mind however dont like high speed level flight youre using radio control0 dont expect lose altitude landing approach giving down elevator airplanes low drag high lift prevent releasing stick0 youll find yourself nearly Continued page 127 February 1993 27 Charles St info & directions call Dr Sandy Frank 817-599-7131 Sponsor WEATHERFORD AERO MODELING SOCIETY FL APR 3Fort Myers FL El 2nd Annual Swap Shop & Auction 900 am -400 pm 800 am Sellers Corkscrew Woodlands Esif 19 W off 75 Corkscrew Rd 1/4 M 75 Larger Hall Tables $10 Advance Reservations Definitely Recommended Admission $2 Paul Barfos 1002 Washington Ave Lehigh FL 33936 PH 813-368-0214 Sponsor SW FLORIDA AERO CLUB LISTING AD INFORMATION NORMAL LISTING AMA sanction issued event event will listed automatically Contest Calendar section listing will give date place name eventplus competition events flying site Contest Director name address Use Supplementary paid Ad space suggested description unusual special events deviations AMA rules significant aspects meet Paid ads may helpful promoting funfly-type meets give directions flying site SUPPLEMENTARY ADS Larger ads can inserted Contest Calendar section paying fee ads accepted AMA-sanctioned events FEE Fees based ad size whether sponsor AMAchartered club AD POLICY SIZE 1/s-in wide either /4 1/2 2/4-in high full size ad appears Contest Calendar section PRICING 3/4$8 1/2$16 2/4$24 time ad run payable advance AMA-chartered clubs pay half rate AD PREPARATION advertiser must prepare Supplementary Ad Ads must full size see above Ads made up dark black white background will reproduce well recommended ad made heavy paper lightweight cardboard PLEASE DO NOT USE PHOTOGRAPHS ON ADS SUBMITTAL DEADLINE effort will made include Supplementary Ads received 14th month issue reaching readers approximately fourth week following month However cannot guaranteed ads published space-available basis normally two-month lead time required inserting Supplementary Ad same deadline will apply sanctioned events listings Questions about either Supplementary Ads regular Sanctioned Events listings should directed Debbie Brown AMAs Competition Department Send ads AMA HO Attention Competition Dept Renew 93 Built FlewlLehman Continued page 20 tempera paints later covered engine area clear dope should also mention tops bottoms fuselages midwing sheeted areas covered classroom tablet backings As project neared completion put several hours covering wings installing hardware radio engine maiden flight Pan Am took place evening April 16 Uncertain outcome made arrangements student present Joshua Smucker young man likely become pilot accompanied full throttle airliner sluggish fresh spring grass did take off fly nicely Unfortunately covering wing began loosen after two laps bring down remarked handy have throttle control cases like too dark repairs second flight Joshua went out again three evenings later time went extremely well Joshua outside circle throttle did takeoffs touch-and-goes slow approaches Communication hand signal week later April 23 students built Pan Am took turns being copilot enjoyed immensely After safety lesson person took turn throttle control about five laps before handing transmitter next pilot Later transferred engine radio Swissair second class its session Both classes preferred high-speed flight after deliberating beauty slow planned approaches gentle flybys persisted flying full tilt Throughout sessions however no matter what kids did throttle planes handled well enriching enjoy able venture kids made sure knew highlight school year Its too bad well probably never know what effect experience futures youngsters Wouldnt neat least came across article 20 30 years now wrote letter editor her/Lehmberg Continued page 27 same altitudethough lot closer little up stick will drop tail increase sink releasing stick will give nice touchdown Like Feather Merchants 72-inch version has wide stall tolerance stalled still mushes along instead pitching down can exploit tight turns glide using some up elevator strong rudder Oh yesI almost forgot Dont think ailerons Feather Merchant want everyone builds Feather Merchant have ball would like picturemaybe have questions problems like drop line 21337 Oak Park Lane Anderson CA 96007 An SASE would appreciated remember reading somewhere closing seems appropriate See ya Chicken House yhear /doBolt Continued page 30 Im going break off discussion point remainder fairly lengthy Save portion continuity reference study concluding part Part Two will cover process developing force arrangements model get ultimate flight performance Ill also talk about trimming methods continued lectricslKopski Continued page 76 fancy wiring harness incorporating double-pole double-throw center-off DPDTCO DP on-off-on switch associated wiring also requires battery made up two half-packs having same cell count cell type idea behind scheme use two packs connected series high power same two packs connected parallel cruise power connection accomplished servo-driven switch described above Thus in-flight switching between two available voltage levelsand off wellis readily accomplished Andjust theres no misunderstanding cells arrangement charged senes Ni-Cds never charged parallel wiring diagram gives details actual use plane motor prop configured cruise climb slightly voltage available paralleled half-packs half voltage higher voltage associated cells series results relatively aggressive climb capability needed center-off switch option allows charge conservation during thermaling Since much total flight time likely occur cruise power levels battery efficiency during periods considerable interest argued parallel-connected half-packs afford increased efficiency since half nominally operating half total motor current Cells tend display somewhat higher capacity lower drain rates conversely somewhat lower capacity higher currents February 1993 127 II
Edition: Model Aviation - 1993/02
Page Numbers: 23, 24, 25, 26, 27, 127
Art Hale Ventura California put Fox 2-powerea i-eather Merchant floats Dont use downthrust its down-elevator-like effect big stab keeps model high speed water making takeoffs difficult Feather Merchant 72 YOU remember provided youre certain age old Lil Abner comic strips Feather Merchants funny little fellows long black coats tall black hats bane Pappy Yokums existencealways trying steal Presarved Turnips secretly made woods beyond view Mammy Yokum succeeded often happeneda personally affronted Pappy would chase shootin iron much result Snuffy Smith strip featured same cameo Remember Snuffy chasing Revenoors confiscating moonshine did happen name model after Pappy Yokums persecutors early days Gas model flying belonged San Antonio Gas Model Airplane Association SAGMAA did quite well competition 1938 1942 attended meets together over Texas Arriving Austin meet morning overheard someone quip Well Feather Merchants coming steal Presarved Turnips Before long Id clapped name onto Bantam-powered original Id good results during 1940 1941 contest seasons Id flown model both competition fun given new covering job second year During period broke three props airplane prop broke after long flight during funsie session Kelly Field club flying site plane escaping both Kellys boundaries lift glided over area filled mesquite trees pear cactus rattlesnakes ended up middle clearing struck solitary mesquite tree just above ground level Only prop broke truly justice world dont fly over pigeons sometimes model came call Feather Merchant traces its origins Cavalier built standard Berkeley kit 1938 Id put together enough pocket money buy kit powered finished plane Brown B Id gotten Christmas Cavalier didnt last long Despite its generous downthrust model made loop takeoff crashed Except wing creamed Next built Lackey Zenith flew like dream wasnt winning anything So came up own design Goon 60% stabilizer radical its day models rate climb however too low time-limited engine run events dominated famous Goldberg Zipper meantime Id become big boyslike Charley Adams Richard Sherman Fred Cordova et alwhom Id idolized just few years before achieving successes rubber designs together ballooning interest aerodynamics got thinking about Berkeley Cavalier model such lemon downthrust effect peers couldnt help except too found uary 1993 23 Old-Timer Flies Anew RC Assist nothing nice say about model fact Berkeley apparently discouraged soon stopped making kit decided build new model using Cavalier wing Money scarce needed salvage whatever could misadventure Model aeronautics game cant blame Ozzie Reynoldss ideas about size scale effect although theories play significant role Theories relating full-scale aerodynamics must modified using both modeling experience hunches Around time designing model Cavalier wing somehow managed have reports aerodynamics mailed NACA now NASA Though partly understood what read correlating modeling experience helped make sense Kutta-Joukowski theory lift completely fascinated Remembering Cavalier its short tail moment arm nearly midfuselage wing great downthrust nose-up instability could guess design hadnt worked Maybe trim right low speed increased airspeed generated strong nose-up moment Maybe much-strengthened downwash wing struck stabilizer mostly its upper surface decreasing stabs angle attack until lifted down looked answers latest design model narrow body belly low center-of-lateral area long tail moment large stab set positive incidence placed wing top cabin fuselage set 20 incidence stab kept conventional Mr Buckmaster Mr Tileson please note refrained using word decalage sake friendly relations using generous dihedral washout tips kept Cardinals excessive downthrustfor reason just discovered high school trigonometry sine tangent angles less 50 virtually equal close zero Therefore downthrust imposes downward force nearly zero making its name improper diverts downwash wing upward direction really made points teacher Mrs Wimberley checked out theory release models airspeed zero propwash strikes large stab Since stab positive angle incidencesay 1 0—and propwash diverted upward 50 good portion stab effectively 60 angle attack hence provides lift As airspeed increases wing lift downwash combination downflow upflow propwash decreases angle attack affected stab area reducing down-elevator-like effect felt sure because recalled way rubber jobs gliders lifted tails strong liftdiving stalling diving again yet still gaining altitude course sometimes model would spiral way down low tip remained stall sure Kutta Joukowski would have approved theory Too tried idea Goon late 1938 could hope right amount stab incidence downthrust Apparently did model flew very well wanted try couple other ideas required money teenagers business acumen sold new plane spectator five bucks Though hadnt included engine Dad disgusted What does know thought just bought Baby Cyclone Cless tank coil condenserfor two bucks five bucks jeans rich spent last months 1939 designing testing Hum-Dinger flew right off drawing board made several flights sheer ecstasy drinking praise about climb glide engine cut takeoff model stalled made nice recovery about three feet above ground Sharing space other side Kelly runway headlight Model Both parties demolished empennage untouched Model owner quite civil said should have moved car started flying models its direction heart broken five-buck fortune long gone Id put dollar Moore prop model instead reworked 25-cent Modelcraft used fun-flying model almost identical Id designed Cavalier wing Because didnt enjoy plotting Eiffel 431 ribs made rib spacing fairly wide prevent covering sagging forward part upper camber Id used 1/ x -in multispars upper lower strip main rear spars would normally have stiffen spars used poster board webbing between ribs produced very strong lightweight wing Incidentally hadnt used multispars provide turbulators forward part upper airfoil method improving airfoil performance yet invented 24 Model Aviation hard Allen Urunga NSW Australia uses 05 26 Surpass FM 72 says flies well though lost wing tip washout Merrilyn Borthwick Chapel Hill OLD Australia wife Airborne Magazines famous columnist Cohn Borthwick Feather Merchant 80 author says planes engine appears either Orwick Anderson Spitfire bottom longerons cemented together point some distance behind rectangular fuselage cross section curving fuselage downward auto matically gave stabilizer little over degree positive incidence Again provided excessive washout tips used generous dihedral model climbed engine cutoff fairly tight quite steep left spiral made nice glide transition wing leveled right glide circle started airplanes life short never called anything except Brown job After talking parents Bantam 19 Christmas 1940 scaled down Brown job 46-inch span Well almost scale also widened chord bit decreased aspect ratio Class model dubbed Feather Merchant Today has SAM Society Antique Modelers OldTimer approval Feather Merchant 46 does original version Feather Merchant 72 featured article 1980 scaled up 46-incher 80 inches SAM RC Assist version will handle 60 ignition engine has since scaled down several sizes SAM approval Feather Merchant 72 FF RC Assist 653-sq-in wing area maximum glow engine 29 weight 45 oz Feather Merchant 46 FF RC Assist wing area 288 sq maximum glow engine 12 weight 20 oz Feather Merchant 80 RC Assist wing area 864 sq maximum glow engine 38 Fox 36 engine displace ment closest 38 weight 60 oz Feather Merchant 56 RC Assist scaled especially Ohlsson 23 event wing area 429 sq maximum glow engine 19 weight 30 oz weights based wing loading 10 oz/sq ft first three Feather Merchants kitted small runs US Germany Michael Volz Modellbau manufactured Feather Merchant 72 distributed kit model has built flown over world its pleasing get letters some builders accompanying photographs show work Bill Forrey Contributing Editor Model Builder won 1984 10th annual Astro Champs electric-powered Feather Merchant 72 published kit review April issue Model Builder have experience assembling builtfrom-sticks models can build Feather Merchant construction notes below point out possible trouble areas suggest ways making job easier Incidentally use CyA cyanoacrylate glues almost exclusively Construction Fuselage Build sides first crafting both same time splitting apart razor blade Cover plan clear plastic backing used rolls MonoKote youre using CyA glues try bend bottom longerons * February 1993 25 Muriel Oglesby Mountain View California learned fly 0S 25-powered Feather Merchant 72 Muriels husband Richard built Author Lehmberg three four Feather Merchant versions left right 72 46 80 Good fliers wide stall tolerance Feather Merchants have SAM Society Antique Modelers Old-Timer approval FUSELAGE VIEW 5/I TAIL OjND 0* P510*50 NO SNOWSTRUE SANE RIOSSEOS POOW /1___ ~T 1i~ND* I [1 P3FRF54IooON NINNOLOWOOUNO m Fl00ONNDON onF 0NOSNDLIN&LANW FRTONEROC000 LAND RG GEAR bETA IF N ERN TO ONES NOOSO E WEt S OSLO CR0000*_____ III WIRDo50lI NDFUSELAGE VIEW SOLON NUONUTO jaoaOLOO EEDE ZIAWZEZZIWZV10 POND 00509 ND MODEL AVIATION FEATHER MERCHANT T2 INTO NEONDE 00 FOEN LEORROTO [J~LOpIY3pENEECp 0 SN PT 0 o poND WING JOINER dry Instead soak part longerons youll bending using either water waterand-ammonia glass cleaner last two methods will quicker longe rons place dry alcohol hair dryer Add planking shown plan point should have two fuselage sides top longerons flapping about Block up sides side flat table install crosspieces same length Constantly check square ensure top side precisely above flat table Lay assembly aside Make turtledeck formers Feather Merchant 46 Feather Merchant 80 use sheet formers other versions use builtup formers prefer build up formers since eliminates cutting holes control rods produces lighter result Cut crosspieces bridge sides beneath formers Also cut few crosspieces remain fitted bottom Finish joining two sides Bring together rear wrap rubberband Beginning bottom install first crosspiece estimate cut bevels required cement piece place Continue until top bottom crosspieces have installed Keep checking alignment go error will permanent create built-in turn generally because pigeon effect direction dont want Pinch bottom longerons together clothespins cement place Sand away vee bottom longerons using sanding block Glue formers followed flapping longerons stringers Complete nose shown plan Make landing gear lace firewall wire Load assembly baking soda saturate CyA prefer use commercial engine mounts bolted firewall rather wooden engine bearers since makes lot easier change engines necessary Install poster board shown plan prefer cover nose window areas poster board using white silver light gray Monotrim simulate win dows Dont forget wing hold-down dowels gussets Building stabilizer basically conven tional working plan includes reed piece doesnt have wet bending Because its opposite curvature will bend covering tightens Install leading edges trailing edges tips Add rib bottoms spars rib tops Build stabilizer elevator piece cutting unit apart after sanding has completed Cap adjoining rib/elevator spars top bottom between ribs procedure fin rudder much same except since no flat bottom ribs attached structure off work surface Builders call air Shim up trailing edge amount indicated pin weigh down build 26 Model Aviation scher Dowling built FM 46 flown 12A Texaco sure looks like Seguin Texas site background Bob Nolan Dunedin Florida pulls free flight version Ohisson Gold Seal Model red silk black trim Three View Page 96 Full-Size Plans Available Page 176 LEFT WING PLAN 808T88800808118008 10080180 0018T 801 ooo OPboa 30008T0 RIBS 8 -00U8L08Too 88000888180Th 0008818008 TOIS 0008 TO 0010080000 OP TOOS SlOE OP 80000 8808 0888 TO 8008 8000 8 00 88018 RIGHT WING PLAN ___________________II TOP 8 0000800 8188 83 tO80880 00 8080000 80088 Top 00 00080T 01008000 8800 8808 TIP 0808100880080800800__________________________________ 808088088 P0888888808088080 888080180000 8008 810880800018 08 80080 ____RA1080800 0 0 0888800888888888008881880000008 800008 08088 80088 R7__0180108888088081080 00008 88881 COP 18 088 808810888 80818088 00 8a08800 8808 800 0088808 118 008 88081 808 8808888 ft.4088 10 00080 00l808 088100 101880050088808801000108 80010088 808000080 S STA8ILI ER I000 81188 0080000 8 1 80 00 8 8 8188 008 00000000100 800008 08Ro1Oo 00000ELEV / I~ MODEL AVIATION FEAThER MERCHANT 72 800080808000 00 8008 Bill Forrey Model Builders sailplane columnist won 10th annual Astra Champs Feather Merchant 72 Electric wing tip washout shown plan Dont try omit washout reduce dihedral Theyre good reason0 youd unhappy Dont forget spar webbing multispar versions Either conventional sparring multispar construction works satisfactorily 46- 72-inch versions used both types like better covering appearance conventional sparring permits dont think possible turbu lator effect multispars particularly Type Sport Wingspan 72 inches Recommended engine size type 29 cu smaller glow ignition Number RC channels recommended Three Expected flying weight 45 ounces Type construction Built-up Type covering/finish recommended Iron-on films silkand-dope effective other hand multispars easy quick light Either type provides good covering contact bottom preserve undercamber Feather Merchants easy fly Keep mind however dont like high speed level flight youre using radio control0 dont expect lose altitude landing approach giving down elevator airplanes low drag high lift prevent releasing stick0 youll find yourself nearly Continued page 127 February 1993 27 Charles St info & directions call Dr Sandy Frank 817-599-7131 Sponsor WEATHERFORD AERO MODELING SOCIETY FL APR 3Fort Myers FL El 2nd Annual Swap Shop & Auction 900 am -400 pm 800 am Sellers Corkscrew Woodlands Esif 19 W off 75 Corkscrew Rd 1/4 M 75 Larger Hall Tables $10 Advance Reservations Definitely Recommended Admission $2 Paul Barfos 1002 Washington Ave Lehigh FL 33936 PH 813-368-0214 Sponsor SW FLORIDA AERO CLUB LISTING AD INFORMATION NORMAL LISTING AMA sanction issued event event will listed automatically Contest Calendar section listing will give date place name eventplus competition events flying site Contest Director name address Use Supplementary paid Ad space suggested description unusual special events deviations AMA rules significant aspects meet Paid ads may helpful promoting funfly-type meets give directions flying site SUPPLEMENTARY ADS Larger ads can inserted Contest Calendar section paying fee ads accepted AMA-sanctioned events FEE Fees based ad size whether sponsor AMAchartered club AD POLICY SIZE 1/s-in wide either /4 1/2 2/4-in high full size ad appears Contest Calendar section PRICING 3/4$8 1/2$16 2/4$24 time ad run payable advance AMA-chartered clubs pay half rate AD PREPARATION advertiser must prepare Supplementary Ad Ads must full size see above Ads made up dark black white background will reproduce well recommended ad made heavy paper lightweight cardboard PLEASE DO NOT USE PHOTOGRAPHS ON ADS SUBMITTAL DEADLINE effort will made include Supplementary Ads received 14th month issue reaching readers approximately fourth week following month However cannot guaranteed ads published space-available basis normally two-month lead time required inserting Supplementary Ad same deadline will apply sanctioned events listings Questions about either Supplementary Ads regular Sanctioned Events listings should directed Debbie Brown AMAs Competition Department Send ads AMA HO Attention Competition Dept Renew 93 Built FlewlLehman Continued page 20 tempera paints later covered engine area clear dope should also mention tops bottoms fuselages midwing sheeted areas covered classroom tablet backings As project neared completion put several hours covering wings installing hardware radio engine maiden flight Pan Am took place evening April 16 Uncertain outcome made arrangements student present Joshua Smucker young man likely become pilot accompanied full throttle airliner sluggish fresh spring grass did take off fly nicely Unfortunately covering wing began loosen after two laps bring down remarked handy have throttle control cases like too dark repairs second flight Joshua went out again three evenings later time went extremely well Joshua outside circle throttle did takeoffs touch-and-goes slow approaches Communication hand signal week later April 23 students built Pan Am took turns being copilot enjoyed immensely After safety lesson person took turn throttle control about five laps before handing transmitter next pilot Later transferred engine radio Swissair second class its session Both classes preferred high-speed flight after deliberating beauty slow planned approaches gentle flybys persisted flying full tilt Throughout sessions however no matter what kids did throttle planes handled well enriching enjoy able venture kids made sure knew highlight school year Its too bad well probably never know what effect experience futures youngsters Wouldnt neat least came across article 20 30 years now wrote letter editor her/Lehmberg Continued page 27 same altitudethough lot closer little up stick will drop tail increase sink releasing stick will give nice touchdown Like Feather Merchants 72-inch version has wide stall tolerance stalled still mushes along instead pitching down can exploit tight turns glide using some up elevator strong rudder Oh yesI almost forgot Dont think ailerons Feather Merchant want everyone builds Feather Merchant have ball would like picturemaybe have questions problems like drop line 21337 Oak Park Lane Anderson CA 96007 An SASE would appreciated remember reading somewhere closing seems appropriate See ya Chicken House yhear /doBolt Continued page 30 Im going break off discussion point remainder fairly lengthy Save portion continuity reference study concluding part Part Two will cover process developing force arrangements model get ultimate flight performance Ill also talk about trimming methods continued lectricslKopski Continued page 76 fancy wiring harness incorporating double-pole double-throw center-off DPDTCO DP on-off-on switch associated wiring also requires battery made up two half-packs having same cell count cell type idea behind scheme use two packs connected series high power same two packs connected parallel cruise power connection accomplished servo-driven switch described above Thus in-flight switching between two available voltage levelsand off wellis readily accomplished Andjust theres no misunderstanding cells arrangement charged senes Ni-Cds never charged parallel wiring diagram gives details actual use plane motor prop configured cruise climb slightly voltage available paralleled half-packs half voltage higher voltage associated cells series results relatively aggressive climb capability needed center-off switch option allows charge conservation during thermaling Since much total flight time likely occur cruise power levels battery efficiency during periods considerable interest argued parallel-connected half-packs afford increased efficiency since half nominally operating half total motor current Cells tend display somewhat higher capacity lower drain rates conversely somewhat lower capacity higher currents February 1993 127 II
Edition: Model Aviation - 1993/02
Page Numbers: 23, 24, 25, 26, 27, 127
Art Hale Ventura California put Fox 2-powerea i-eather Merchant floats Dont use downthrust its down-elevator-like effect big stab keeps model high speed water making takeoffs difficult Feather Merchant 72 YOU remember provided youre certain age old Lil Abner comic strips Feather Merchants funny little fellows long black coats tall black hats bane Pappy Yokums existencealways trying steal Presarved Turnips secretly made woods beyond view Mammy Yokum succeeded often happeneda personally affronted Pappy would chase shootin iron much result Snuffy Smith strip featured same cameo Remember Snuffy chasing Revenoors confiscating moonshine did happen name model after Pappy Yokums persecutors early days Gas model flying belonged San Antonio Gas Model Airplane Association SAGMAA did quite well competition 1938 1942 attended meets together over Texas Arriving Austin meet morning overheard someone quip Well Feather Merchants coming steal Presarved Turnips Before long Id clapped name onto Bantam-powered original Id good results during 1940 1941 contest seasons Id flown model both competition fun given new covering job second year During period broke three props airplane prop broke after long flight during funsie session Kelly Field club flying site plane escaping both Kellys boundaries lift glided over area filled mesquite trees pear cactus rattlesnakes ended up middle clearing struck solitary mesquite tree just above ground level Only prop broke truly justice world dont fly over pigeons sometimes model came call Feather Merchant traces its origins Cavalier built standard Berkeley kit 1938 Id put together enough pocket money buy kit powered finished plane Brown B Id gotten Christmas Cavalier didnt last long Despite its generous downthrust model made loop takeoff crashed Except wing creamed Next built Lackey Zenith flew like dream wasnt winning anything So came up own design Goon 60% stabilizer radical its day models rate climb however too low time-limited engine run events dominated famous Goldberg Zipper meantime Id become big boyslike Charley Adams Richard Sherman Fred Cordova et alwhom Id idolized just few years before achieving successes rubber designs together ballooning interest aerodynamics got thinking about Berkeley Cavalier model such lemon downthrust effect peers couldnt help except too found uary 1993 23 Old-Timer Flies Anew RC Assist nothing nice say about model fact Berkeley apparently discouraged soon stopped making kit decided build new model using Cavalier wing Money scarce needed salvage whatever could misadventure Model aeronautics game cant blame Ozzie Reynoldss ideas about size scale effect although theories play significant role Theories relating full-scale aerodynamics must modified using both modeling experience hunches Around time designing model Cavalier wing somehow managed have reports aerodynamics mailed NACA now NASA Though partly understood what read correlating modeling experience helped make sense Kutta-Joukowski theory lift completely fascinated Remembering Cavalier its short tail moment arm nearly midfuselage wing great downthrust nose-up instability could guess design hadnt worked Maybe trim right low speed increased airspeed generated strong nose-up moment Maybe much-strengthened downwash wing struck stabilizer mostly its upper surface decreasing stabs angle attack until lifted down looked answers latest design model narrow body belly low center-of-lateral area long tail moment large stab set positive incidence placed wing top cabin fuselage set 20 incidence stab kept conventional Mr Buckmaster Mr Tileson please note refrained using word decalage sake friendly relations using generous dihedral washout tips kept Cardinals excessive downthrustfor reason just discovered high school trigonometry sine tangent angles less 50 virtually equal close zero Therefore downthrust imposes downward force nearly zero making its name improper diverts downwash wing upward direction really made points teacher Mrs Wimberley checked out theory release models airspeed zero propwash strikes large stab Since stab positive angle incidencesay 1 0—and propwash diverted upward 50 good portion stab effectively 60 angle attack hence provides lift As airspeed increases wing lift downwash combination downflow upflow propwash decreases angle attack affected stab area reducing down-elevator-like effect felt sure because recalled way rubber jobs gliders lifted tails strong liftdiving stalling diving again yet still gaining altitude course sometimes model would spiral way down low tip remained stall sure Kutta Joukowski would have approved theory Too tried idea Goon late 1938 could hope right amount stab incidence downthrust Apparently did model flew very well wanted try couple other ideas required money teenagers business acumen sold new plane spectator five bucks Though hadnt included engine Dad disgusted What does know thought just bought Baby Cyclone Cless tank coil condenserfor two bucks five bucks jeans rich spent last months 1939 designing testing Hum-Dinger flew right off drawing board made several flights sheer ecstasy drinking praise about climb glide engine cut takeoff model stalled made nice recovery about three feet above ground Sharing space other side Kelly runway headlight Model Both parties demolished empennage untouched Model owner quite civil said should have moved car started flying models its direction heart broken five-buck fortune long gone Id put dollar Moore prop model instead reworked 25-cent Modelcraft used fun-flying model almost identical Id designed Cavalier wing Because didnt enjoy plotting Eiffel 431 ribs made rib spacing fairly wide prevent covering sagging forward part upper camber Id used 1/ x -in multispars upper lower strip main rear spars would normally have stiffen spars used poster board webbing between ribs produced very strong lightweight wing Incidentally hadnt used multispars provide turbulators forward part upper airfoil method improving airfoil performance yet invented 24 Model Aviation hard Allen Urunga NSW Australia uses 05 26 Surpass FM 72 says flies well though lost wing tip washout Merrilyn Borthwick Chapel Hill OLD Australia wife Airborne Magazines famous columnist Cohn Borthwick Feather Merchant 80 author says planes engine appears either Orwick Anderson Spitfire bottom longerons cemented together point some distance behind rectangular fuselage cross section curving fuselage downward auto matically gave stabilizer little over degree positive incidence Again provided excessive washout tips used generous dihedral model climbed engine cutoff fairly tight quite steep left spiral made nice glide transition wing leveled right glide circle started airplanes life short never called anything except Brown job After talking parents Bantam 19 Christmas 1940 scaled down Brown job 46-inch span Well almost scale also widened chord bit decreased aspect ratio Class model dubbed Feather Merchant Today has SAM Society Antique Modelers OldTimer approval Feather Merchant 46 does original version Feather Merchant 72 featured article 1980 scaled up 46-incher 80 inches SAM RC Assist version will handle 60 ignition engine has since scaled down several sizes SAM approval Feather Merchant 72 FF RC Assist 653-sq-in wing area maximum glow engine 29 weight 45 oz Feather Merchant 46 FF RC Assist wing area 288 sq maximum glow engine 12 weight 20 oz Feather Merchant 80 RC Assist wing area 864 sq maximum glow engine 38 Fox 36 engine displace ment closest 38 weight 60 oz Feather Merchant 56 RC Assist scaled especially Ohlsson 23 event wing area 429 sq maximum glow engine 19 weight 30 oz weights based wing loading 10 oz/sq ft first three Feather Merchants kitted small runs US Germany Michael Volz Modellbau manufactured Feather Merchant 72 distributed kit model has built flown over world its pleasing get letters some builders accompanying photographs show work Bill Forrey Contributing Editor Model Builder won 1984 10th annual Astro Champs electric-powered Feather Merchant 72 published kit review April issue Model Builder have experience assembling builtfrom-sticks models can build Feather Merchant construction notes below point out possible trouble areas suggest ways making job easier Incidentally use CyA cyanoacrylate glues almost exclusively Construction Fuselage Build sides first crafting both same time splitting apart razor blade Cover plan clear plastic backing used rolls MonoKote youre using CyA glues try bend bottom longerons * February 1993 25 Muriel Oglesby Mountain View California learned fly 0S 25-powered Feather Merchant 72 Muriels husband Richard built Author Lehmberg three four Feather Merchant versions left right 72 46 80 Good fliers wide stall tolerance Feather Merchants have SAM Society Antique Modelers Old-Timer approval FUSELAGE VIEW 5/I TAIL OjND 0* P510*50 NO SNOWSTRUE SANE RIOSSEOS POOW /1___ ~T 1i~ND* I [1 P3FRF54IooON NINNOLOWOOUNO m Fl00ONNDON onF 0NOSNDLIN&LANW FRTONEROC000 LAND RG GEAR bETA IF N ERN TO ONES NOOSO E WEt S OSLO CR0000*_____ III WIRDo50lI NDFUSELAGE VIEW SOLON NUONUTO jaoaOLOO EEDE ZIAWZEZZIWZV10 POND 00509 ND MODEL AVIATION FEATHER MERCHANT T2 INTO NEONDE 00 FOEN LEORROTO [J~LOpIY3pENEECp 0 SN PT 0 o poND WING JOINER dry Instead soak part longerons youll bending using either water waterand-ammonia glass cleaner last two methods will quicker longe rons place dry alcohol hair dryer Add planking shown plan point should have two fuselage sides top longerons flapping about Block up sides side flat table install crosspieces same length Constantly check square ensure top side precisely above flat table Lay assembly aside Make turtledeck formers Feather Merchant 46 Feather Merchant 80 use sheet formers other versions use builtup formers prefer build up formers since eliminates cutting holes control rods produces lighter result Cut crosspieces bridge sides beneath formers Also cut few crosspieces remain fitted bottom Finish joining two sides Bring together rear wrap rubberband Beginning bottom install first crosspiece estimate cut bevels required cement piece place Continue until top bottom crosspieces have installed Keep checking alignment go error will permanent create built-in turn generally because pigeon effect direction dont want Pinch bottom longerons together clothespins cement place Sand away vee bottom longerons using sanding block Glue formers followed flapping longerons stringers Complete nose shown plan Make landing gear lace firewall wire Load assembly baking soda saturate CyA prefer use commercial engine mounts bolted firewall rather wooden engine bearers since makes lot easier change engines necessary Install poster board shown plan prefer cover nose window areas poster board using white silver light gray Monotrim simulate win dows Dont forget wing hold-down dowels gussets Building stabilizer basically conven tional working plan includes reed piece doesnt have wet bending Because its opposite curvature will bend covering tightens Install leading edges trailing edges tips Add rib bottoms spars rib tops Build stabilizer elevator piece cutting unit apart after sanding has completed Cap adjoining rib/elevator spars top bottom between ribs procedure fin rudder much same except since no flat bottom ribs attached structure off work surface Builders call air Shim up trailing edge amount indicated pin weigh down build 26 Model Aviation scher Dowling built FM 46 flown 12A Texaco sure looks like Seguin Texas site background Bob Nolan Dunedin Florida pulls free flight version Ohisson Gold Seal Model red silk black trim Three View Page 96 Full-Size Plans Available Page 176 LEFT WING PLAN 808T88800808118008 10080180 0018T 801 ooo OPboa 30008T0 RIBS 8 -00U8L08Too 88000888180Th 0008818008 TOIS 0008 TO 0010080000 OP TOOS SlOE OP 80000 8808 0888 TO 8008 8000 8 00 88018 RIGHT WING PLAN ___________________II TOP 8 0000800 8188 83 tO80880 00 8080000 80088 Top 00 00080T 01008000 8800 8808 TIP 0808100880080800800__________________________________ 808088088 P0888888808088080 888080180000 8008 810880800018 08 80080 ____RA1080800 0 0 0888800888888888008881880000008 800008 08088 80088 R7__0180108888088081080 00008 88881 COP 18 088 808810888 80818088 00 8a08800 8808 800 0088808 118 008 88081 808 8808888 ft.4088 10 00080 00l808 088100 101880050088808801000108 80010088 808000080 S STA8ILI ER I000 81188 0080000 8 1 80 00 8 8 8188 008 00000000100 800008 08Ro1Oo 00000ELEV / I~ MODEL AVIATION FEAThER MERCHANT 72 800080808000 00 8008 Bill Forrey Model Builders sailplane columnist won 10th annual Astra Champs Feather Merchant 72 Electric wing tip washout shown plan Dont try omit washout reduce dihedral Theyre good reason0 youd unhappy Dont forget spar webbing multispar versions Either conventional sparring multispar construction works satisfactorily 46- 72-inch versions used both types like better covering appearance conventional sparring permits dont think possible turbu lator effect multispars particularly Type Sport Wingspan 72 inches Recommended engine size type 29 cu smaller glow ignition Number RC channels recommended Three Expected flying weight 45 ounces Type construction Built-up Type covering/finish recommended Iron-on films silkand-dope effective other hand multispars easy quick light Either type provides good covering contact bottom preserve undercamber Feather Merchants easy fly Keep mind however dont like high speed level flight youre using radio control0 dont expect lose altitude landing approach giving down elevator airplanes low drag high lift prevent releasing stick0 youll find yourself nearly Continued page 127 February 1993 27 Charles St info & directions call Dr Sandy Frank 817-599-7131 Sponsor WEATHERFORD AERO MODELING SOCIETY FL APR 3Fort Myers FL El 2nd Annual Swap Shop & Auction 900 am -400 pm 800 am Sellers Corkscrew Woodlands Esif 19 W off 75 Corkscrew Rd 1/4 M 75 Larger Hall Tables $10 Advance Reservations Definitely Recommended Admission $2 Paul Barfos 1002 Washington Ave Lehigh FL 33936 PH 813-368-0214 Sponsor SW FLORIDA AERO CLUB LISTING AD INFORMATION NORMAL LISTING AMA sanction issued event event will listed automatically Contest Calendar section listing will give date place name eventplus competition events flying site Contest Director name address Use Supplementary paid Ad space suggested description unusual special events deviations AMA rules significant aspects meet Paid ads may helpful promoting funfly-type meets give directions flying site SUPPLEMENTARY ADS Larger ads can inserted Contest Calendar section paying fee ads accepted AMA-sanctioned events FEE Fees based ad size whether sponsor AMAchartered club AD POLICY SIZE 1/s-in wide either /4 1/2 2/4-in high full size ad appears Contest Calendar section PRICING 3/4$8 1/2$16 2/4$24 time ad run payable advance AMA-chartered clubs pay half rate AD PREPARATION advertiser must prepare Supplementary Ad Ads must full size see above Ads made up dark black white background will reproduce well recommended ad made heavy paper lightweight cardboard PLEASE DO NOT USE PHOTOGRAPHS ON ADS SUBMITTAL DEADLINE effort will made include Supplementary Ads received 14th month issue reaching readers approximately fourth week following month However cannot guaranteed ads published space-available basis normally two-month lead time required inserting Supplementary Ad same deadline will apply sanctioned events listings Questions about either Supplementary Ads regular Sanctioned Events listings should directed Debbie Brown AMAs Competition Department Send ads AMA HO Attention Competition Dept Renew 93 Built FlewlLehman Continued page 20 tempera paints later covered engine area clear dope should also mention tops bottoms fuselages midwing sheeted areas covered classroom tablet backings As project neared completion put several hours covering wings installing hardware radio engine maiden flight Pan Am took place evening April 16 Uncertain outcome made arrangements student present Joshua Smucker young man likely become pilot accompanied full throttle airliner sluggish fresh spring grass did take off fly nicely Unfortunately covering wing began loosen after two laps bring down remarked handy have throttle control cases like too dark repairs second flight Joshua went out again three evenings later time went extremely well Joshua outside circle throttle did takeoffs touch-and-goes slow approaches Communication hand signal week later April 23 students built Pan Am took turns being copilot enjoyed immensely After safety lesson person took turn throttle control about five laps before handing transmitter next pilot Later transferred engine radio Swissair second class its session Both classes preferred high-speed flight after deliberating beauty slow planned approaches gentle flybys persisted flying full tilt Throughout sessions however no matter what kids did throttle planes handled well enriching enjoy able venture kids made sure knew highlight school year Its too bad well probably never know what effect experience futures youngsters Wouldnt neat least came across article 20 30 years now wrote letter editor her/Lehmberg Continued page 27 same altitudethough lot closer little up stick will drop tail increase sink releasing stick will give nice touchdown Like Feather Merchants 72-inch version has wide stall tolerance stalled still mushes along instead pitching down can exploit tight turns glide using some up elevator strong rudder Oh yesI almost forgot Dont think ailerons Feather Merchant want everyone builds Feather Merchant have ball would like picturemaybe have questions problems like drop line 21337 Oak Park Lane Anderson CA 96007 An SASE would appreciated remember reading somewhere closing seems appropriate See ya Chicken House yhear /doBolt Continued page 30 Im going break off discussion point remainder fairly lengthy Save portion continuity reference study concluding part Part Two will cover process developing force arrangements model get ultimate flight performance Ill also talk about trimming methods continued lectricslKopski Continued page 76 fancy wiring harness incorporating double-pole double-throw center-off DPDTCO DP on-off-on switch associated wiring also requires battery made up two half-packs having same cell count cell type idea behind scheme use two packs connected series high power same two packs connected parallel cruise power connection accomplished servo-driven switch described above Thus in-flight switching between two available voltage levelsand off wellis readily accomplished Andjust theres no misunderstanding cells arrangement charged senes Ni-Cds never charged parallel wiring diagram gives details actual use plane motor prop configured cruise climb slightly voltage available paralleled half-packs half voltage higher voltage associated cells series results relatively aggressive climb capability needed center-off switch option allows charge conservation during thermaling Since much total flight time likely occur cruise power levels battery efficiency during periods considerable interest argued parallel-connected half-packs afford increased efficiency since half nominally operating half total motor current Cells tend display somewhat higher capacity lower drain rates conversely somewhat lower capacity higher currents February 1993 127 II
Edition: Model Aviation - 1993/02
Page Numbers: 23, 24, 25, 26, 27, 127
Art Hale Ventura California put Fox 2-powerea i-eather Merchant floats Dont use downthrust its down-elevator-like effect big stab keeps model high speed water making takeoffs difficult Feather Merchant 72 YOU remember provided youre certain age old Lil Abner comic strips Feather Merchants funny little fellows long black coats tall black hats bane Pappy Yokums existencealways trying steal Presarved Turnips secretly made woods beyond view Mammy Yokum succeeded often happeneda personally affronted Pappy would chase shootin iron much result Snuffy Smith strip featured same cameo Remember Snuffy chasing Revenoors confiscating moonshine did happen name model after Pappy Yokums persecutors early days Gas model flying belonged San Antonio Gas Model Airplane Association SAGMAA did quite well competition 1938 1942 attended meets together over Texas Arriving Austin meet morning overheard someone quip Well Feather Merchants coming steal Presarved Turnips Before long Id clapped name onto Bantam-powered original Id good results during 1940 1941 contest seasons Id flown model both competition fun given new covering job second year During period broke three props airplane prop broke after long flight during funsie session Kelly Field club flying site plane escaping both Kellys boundaries lift glided over area filled mesquite trees pear cactus rattlesnakes ended up middle clearing struck solitary mesquite tree just above ground level Only prop broke truly justice world dont fly over pigeons sometimes model came call Feather Merchant traces its origins Cavalier built standard Berkeley kit 1938 Id put together enough pocket money buy kit powered finished plane Brown B Id gotten Christmas Cavalier didnt last long Despite its generous downthrust model made loop takeoff crashed Except wing creamed Next built Lackey Zenith flew like dream wasnt winning anything So came up own design Goon 60% stabilizer radical its day models rate climb however too low time-limited engine run events dominated famous Goldberg Zipper meantime Id become big boyslike Charley Adams Richard Sherman Fred Cordova et alwhom Id idolized just few years before achieving successes rubber designs together ballooning interest aerodynamics got thinking about Berkeley Cavalier model such lemon downthrust effect peers couldnt help except too found uary 1993 23 Old-Timer Flies Anew RC Assist nothing nice say about model fact Berkeley apparently discouraged soon stopped making kit decided build new model using Cavalier wing Money scarce needed salvage whatever could misadventure Model aeronautics game cant blame Ozzie Reynoldss ideas about size scale effect although theories play significant role Theories relating full-scale aerodynamics must modified using both modeling experience hunches Around time designing model Cavalier wing somehow managed have reports aerodynamics mailed NACA now NASA Though partly understood what read correlating modeling experience helped make sense Kutta-Joukowski theory lift completely fascinated Remembering Cavalier its short tail moment arm nearly midfuselage wing great downthrust nose-up instability could guess design hadnt worked Maybe trim right low speed increased airspeed generated strong nose-up moment Maybe much-strengthened downwash wing struck stabilizer mostly its upper surface decreasing stabs angle attack until lifted down looked answers latest design model narrow body belly low center-of-lateral area long tail moment large stab set positive incidence placed wing top cabin fuselage set 20 incidence stab kept conventional Mr Buckmaster Mr Tileson please note refrained using word decalage sake friendly relations using generous dihedral washout tips kept Cardinals excessive downthrustfor reason just discovered high school trigonometry sine tangent angles less 50 virtually equal close zero Therefore downthrust imposes downward force nearly zero making its name improper diverts downwash wing upward direction really made points teacher Mrs Wimberley checked out theory release models airspeed zero propwash strikes large stab Since stab positive angle incidencesay 1 0—and propwash diverted upward 50 good portion stab effectively 60 angle attack hence provides lift As airspeed increases wing lift downwash combination downflow upflow propwash decreases angle attack affected stab area reducing down-elevator-like effect felt sure because recalled way rubber jobs gliders lifted tails strong liftdiving stalling diving again yet still gaining altitude course sometimes model would spiral way down low tip remained stall sure Kutta Joukowski would have approved theory Too tried idea Goon late 1938 could hope right amount stab incidence downthrust Apparently did model flew very well wanted try couple other ideas required money teenagers business acumen sold new plane spectator five bucks Though hadnt included engine Dad disgusted What does know thought just bought Baby Cyclone Cless tank coil condenserfor two bucks five bucks jeans rich spent last months 1939 designing testing Hum-Dinger flew right off drawing board made several flights sheer ecstasy drinking praise about climb glide engine cut takeoff model stalled made nice recovery about three feet above ground Sharing space other side Kelly runway headlight Model Both parties demolished empennage untouched Model owner quite civil said should have moved car started flying models its direction heart broken five-buck fortune long gone Id put dollar Moore prop model instead reworked 25-cent Modelcraft used fun-flying model almost identical Id designed Cavalier wing Because didnt enjoy plotting Eiffel 431 ribs made rib spacing fairly wide prevent covering sagging forward part upper camber Id used 1/ x -in multispars upper lower strip main rear spars would normally have stiffen spars used poster board webbing between ribs produced very strong lightweight wing Incidentally hadnt used multispars provide turbulators forward part upper airfoil method improving airfoil performance yet invented 24 Model Aviation hard Allen Urunga NSW Australia uses 05 26 Surpass FM 72 says flies well though lost wing tip washout Merrilyn Borthwick Chapel Hill OLD Australia wife Airborne Magazines famous columnist Cohn Borthwick Feather Merchant 80 author says planes engine appears either Orwick Anderson Spitfire bottom longerons cemented together point some distance behind rectangular fuselage cross section curving fuselage downward auto matically gave stabilizer little over degree positive incidence Again provided excessive washout tips used generous dihedral model climbed engine cutoff fairly tight quite steep left spiral made nice glide transition wing leveled right glide circle started airplanes life short never called anything except Brown job After talking parents Bantam 19 Christmas 1940 scaled down Brown job 46-inch span Well almost scale also widened chord bit decreased aspect ratio Class model dubbed Feather Merchant Today has SAM Society Antique Modelers OldTimer approval Feather Merchant 46 does original version Feather Merchant 72 featured article 1980 scaled up 46-incher 80 inches SAM RC Assist version will handle 60 ignition engine has since scaled down several sizes SAM approval Feather Merchant 72 FF RC Assist 653-sq-in wing area maximum glow engine 29 weight 45 oz Feather Merchant 46 FF RC Assist wing area 288 sq maximum glow engine 12 weight 20 oz Feather Merchant 80 RC Assist wing area 864 sq maximum glow engine 38 Fox 36 engine displace ment closest 38 weight 60 oz Feather Merchant 56 RC Assist scaled especially Ohlsson 23 event wing area 429 sq maximum glow engine 19 weight 30 oz weights based wing loading 10 oz/sq ft first three Feather Merchants kitted small runs US Germany Michael Volz Modellbau manufactured Feather Merchant 72 distributed kit model has built flown over world its pleasing get letters some builders accompanying photographs show work Bill Forrey Contributing Editor Model Builder won 1984 10th annual Astro Champs electric-powered Feather Merchant 72 published kit review April issue Model Builder have experience assembling builtfrom-sticks models can build Feather Merchant construction notes below point out possible trouble areas suggest ways making job easier Incidentally use CyA cyanoacrylate glues almost exclusively Construction Fuselage Build sides first crafting both same time splitting apart razor blade Cover plan clear plastic backing used rolls MonoKote youre using CyA glues try bend bottom longerons * February 1993 25 Muriel Oglesby Mountain View California learned fly 0S 25-powered Feather Merchant 72 Muriels husband Richard built Author Lehmberg three four Feather Merchant versions left right 72 46 80 Good fliers wide stall tolerance Feather Merchants have SAM Society Antique Modelers Old-Timer approval FUSELAGE VIEW 5/I TAIL OjND 0* P510*50 NO SNOWSTRUE SANE RIOSSEOS POOW /1___ ~T 1i~ND* I [1 P3FRF54IooON NINNOLOWOOUNO m Fl00ONNDON onF 0NOSNDLIN&LANW FRTONEROC000 LAND RG GEAR bETA IF N ERN TO ONES NOOSO E WEt S OSLO CR0000*_____ III WIRDo50lI NDFUSELAGE VIEW SOLON NUONUTO jaoaOLOO EEDE ZIAWZEZZIWZV10 POND 00509 ND MODEL AVIATION FEATHER MERCHANT T2 INTO NEONDE 00 FOEN LEORROTO [J~LOpIY3pENEECp 0 SN PT 0 o poND WING JOINER dry Instead soak part longerons youll bending using either water waterand-ammonia glass cleaner last two methods will quicker longe rons place dry alcohol hair dryer Add planking shown plan point should have two fuselage sides top longerons flapping about Block up sides side flat table install crosspieces same length Constantly check square ensure top side precisely above flat table Lay assembly aside Make turtledeck formers Feather Merchant 46 Feather Merchant 80 use sheet formers other versions use builtup formers prefer build up formers since eliminates cutting holes control rods produces lighter result Cut crosspieces bridge sides beneath formers Also cut few crosspieces remain fitted bottom Finish joining two sides Bring together rear wrap rubberband Beginning bottom install first crosspiece estimate cut bevels required cement piece place Continue until top bottom crosspieces have installed Keep checking alignment go error will permanent create built-in turn generally because pigeon effect direction dont want Pinch bottom longerons together clothespins cement place Sand away vee bottom longerons using sanding block Glue formers followed flapping longerons stringers Complete nose shown plan Make landing gear lace firewall wire Load assembly baking soda saturate CyA prefer use commercial engine mounts bolted firewall rather wooden engine bearers since makes lot easier change engines necessary Install poster board shown plan prefer cover nose window areas poster board using white silver light gray Monotrim simulate win dows Dont forget wing hold-down dowels gussets Building stabilizer basically conven tional working plan includes reed piece doesnt have wet bending Because its opposite curvature will bend covering tightens Install leading edges trailing edges tips Add rib bottoms spars rib tops Build stabilizer elevator piece cutting unit apart after sanding has completed Cap adjoining rib/elevator spars top bottom between ribs procedure fin rudder much same except since no flat bottom ribs attached structure off work surface Builders call air Shim up trailing edge amount indicated pin weigh down build 26 Model Aviation scher Dowling built FM 46 flown 12A Texaco sure looks like Seguin Texas site background Bob Nolan Dunedin Florida pulls free flight version Ohisson Gold Seal Model red silk black trim Three View Page 96 Full-Size Plans Available Page 176 LEFT WING PLAN 808T88800808118008 10080180 0018T 801 ooo OPboa 30008T0 RIBS 8 -00U8L08Too 88000888180Th 0008818008 TOIS 0008 TO 0010080000 OP TOOS SlOE OP 80000 8808 0888 TO 8008 8000 8 00 88018 RIGHT WING PLAN ___________________II TOP 8 0000800 8188 83 tO80880 00 8080000 80088 Top 00 00080T 01008000 8800 8808 TIP 0808100880080800800__________________________________ 808088088 P0888888808088080 888080180000 8008 810880800018 08 80080 ____RA1080800 0 0 0888800888888888008881880000008 800008 08088 80088 R7__0180108888088081080 00008 88881 COP 18 088 808810888 80818088 00 8a08800 8808 800 0088808 118 008 88081 808 8808888 ft.4088 10 00080 00l808 088100 101880050088808801000108 80010088 808000080 S STA8ILI ER I000 81188 0080000 8 1 80 00 8 8 8188 008 00000000100 800008 08Ro1Oo 00000ELEV / I~ MODEL AVIATION FEAThER MERCHANT 72 800080808000 00 8008 Bill Forrey Model Builders sailplane columnist won 10th annual Astra Champs Feather Merchant 72 Electric wing tip washout shown plan Dont try omit washout reduce dihedral Theyre good reason0 youd unhappy Dont forget spar webbing multispar versions Either conventional sparring multispar construction works satisfactorily 46- 72-inch versions used both types like better covering appearance conventional sparring permits dont think possible turbu lator effect multispars particularly Type Sport Wingspan 72 inches Recommended engine size type 29 cu smaller glow ignition Number RC channels recommended Three Expected flying weight 45 ounces Type construction Built-up Type covering/finish recommended Iron-on films silkand-dope effective other hand multispars easy quick light Either type provides good covering contact bottom preserve undercamber Feather Merchants easy fly Keep mind however dont like high speed level flight youre using radio control0 dont expect lose altitude landing approach giving down elevator airplanes low drag high lift prevent releasing stick0 youll find yourself nearly Continued page 127 February 1993 27 Charles St info & directions call Dr Sandy Frank 817-599-7131 Sponsor WEATHERFORD AERO MODELING SOCIETY FL APR 3Fort Myers FL El 2nd Annual Swap Shop & Auction 900 am -400 pm 800 am Sellers Corkscrew Woodlands Esif 19 W off 75 Corkscrew Rd 1/4 M 75 Larger Hall Tables $10 Advance Reservations Definitely Recommended Admission $2 Paul Barfos 1002 Washington Ave Lehigh FL 33936 PH 813-368-0214 Sponsor SW FLORIDA AERO CLUB LISTING AD INFORMATION NORMAL LISTING AMA sanction issued event event will listed automatically Contest Calendar section listing will give date place name eventplus competition events flying site Contest Director name address Use Supplementary paid Ad space suggested description unusual special events deviations AMA rules significant aspects meet Paid ads may helpful promoting funfly-type meets give directions flying site SUPPLEMENTARY ADS Larger ads can inserted Contest Calendar section paying fee ads accepted AMA-sanctioned events FEE Fees based ad size whether sponsor AMAchartered club AD POLICY SIZE 1/s-in wide either /4 1/2 2/4-in high full size ad appears Contest Calendar section PRICING 3/4$8 1/2$16 2/4$24 time ad run payable advance AMA-chartered clubs pay half rate AD PREPARATION advertiser must prepare Supplementary Ad Ads must full size see above Ads made up dark black white background will reproduce well recommended ad made heavy paper lightweight cardboard PLEASE DO NOT USE PHOTOGRAPHS ON ADS SUBMITTAL DEADLINE effort will made include Supplementary Ads received 14th month issue reaching readers approximately fourth week following month However cannot guaranteed ads published space-available basis normally two-month lead time required inserting Supplementary Ad same deadline will apply sanctioned events listings Questions about either Supplementary Ads regular Sanctioned Events listings should directed Debbie Brown AMAs Competition Department Send ads AMA HO Attention Competition Dept Renew 93 Built FlewlLehman Continued page 20 tempera paints later covered engine area clear dope should also mention tops bottoms fuselages midwing sheeted areas covered classroom tablet backings As project neared completion put several hours covering wings installing hardware radio engine maiden flight Pan Am took place evening April 16 Uncertain outcome made arrangements student present Joshua Smucker young man likely become pilot accompanied full throttle airliner sluggish fresh spring grass did take off fly nicely Unfortunately covering wing began loosen after two laps bring down remarked handy have throttle control cases like too dark repairs second flight Joshua went out again three evenings later time went extremely well Joshua outside circle throttle did takeoffs touch-and-goes slow approaches Communication hand signal week later April 23 students built Pan Am took turns being copilot enjoyed immensely After safety lesson person took turn throttle control about five laps before handing transmitter next pilot Later transferred engine radio Swissair second class its session Both classes preferred high-speed flight after deliberating beauty slow planned approaches gentle flybys persisted flying full tilt Throughout sessions however no matter what kids did throttle planes handled well enriching enjoy able venture kids made sure knew highlight school year Its too bad well probably never know what effect experience futures youngsters Wouldnt neat least came across article 20 30 years now wrote letter editor her/Lehmberg Continued page 27 same altitudethough lot closer little up stick will drop tail increase sink releasing stick will give nice touchdown Like Feather Merchants 72-inch version has wide stall tolerance stalled still mushes along instead pitching down can exploit tight turns glide using some up elevator strong rudder Oh yesI almost forgot Dont think ailerons Feather Merchant want everyone builds Feather Merchant have ball would like picturemaybe have questions problems like drop line 21337 Oak Park Lane Anderson CA 96007 An SASE would appreciated remember reading somewhere closing seems appropriate See ya Chicken House yhear /doBolt Continued page 30 Im going break off discussion point remainder fairly lengthy Save portion continuity reference study concluding part Part Two will cover process developing force arrangements model get ultimate flight performance Ill also talk about trimming methods continued lectricslKopski Continued page 76 fancy wiring harness incorporating double-pole double-throw center-off DPDTCO DP on-off-on switch associated wiring also requires battery made up two half-packs having same cell count cell type idea behind scheme use two packs connected series high power same two packs connected parallel cruise power connection accomplished servo-driven switch described above Thus in-flight switching between two available voltage levelsand off wellis readily accomplished Andjust theres no misunderstanding cells arrangement charged senes Ni-Cds never charged parallel wiring diagram gives details actual use plane motor prop configured cruise climb slightly voltage available paralleled half-packs half voltage higher voltage associated cells series results relatively aggressive climb capability needed center-off switch option allows charge conservation during thermaling Since much total flight time likely occur cruise power levels battery efficiency during periods considerable interest argued parallel-connected half-packs afford increased efficiency since half nominally operating half total motor current Cells tend display somewhat higher capacity lower drain rates conversely somewhat lower capacity higher currents February 1993 127 II