The Art and Science of Pseudoaerodynamics

Fig 1 model high ugliness drag Such drag cannot measured easily -y Fig 2 model low ugliness drag Ugliness drag previously undocumented Barnaby Wainfan Have ever wondered basically similar model aircraft fly differ ently author takes in-depth look related subjects results may startle youIllustrations John Hunton MODELERS just like airplane design ers perpetually exploring fascinat ing gray area between art science much both process creating model attractive flies well science aerodynamics well documented elsewhere purpose article shed some light less well documented forces affecting model airplane Much airplane model design rigidly scientific configuration airplane determined its design mission mission specifies size wing loading airfoil characteristics etc air plane must have order its job As aerodynamicist can tell performance airplane determined such parameters wing loading aspect ratio lift coefficient Reynolds Number span efficiency others effects of scientifically deter mined quantities can written down form set graphs tables performance airplane can determined What graphs say airplane will Period Modelers instinctively dissatisfied rigid analytical view craft something aesthetically displeasing about mechanistic point view need design good model set tables graphs no room individual self-expression much part enjoyment modeling no room innovation no room art modeler tends look things subjective way will tell looks right itwillflyright Usuallyitdoes Nicely proportioned models balanced eye-pleasing lines usually fly very well other hand ugly awkward ships rarely None can determined con sulting tables graphs An perplexing effect may observed two modelers build ma chines same design nero dynamicists point view two planes theoretically identical should fly identically dont prettier model always seems fly better drab Obviously aerodynamicists have overlooked something order understand what has overlooked must expand 58 Model Aviation Fig 3 non-sleek model just seems go slow wallow over sky -y Fig 4 Sleek airplanes lust go Waster nonsleek counterparts speed study model design previously unexplored area pseudoaerodynamics After much investigation previously un documented component drag model has identified compo nent related directly appearance model known ugliness drag described ugliness drag coeffi cient Cdu normalized re spect area dynamic pressure exactly same way drag coefficients defined classical aerodynamic theory Cdu direct function lines finish model Cdu 0du GLOSS SLEEKNESS Although ugliness drag cannot easily measured apparently constitutes somewhere between 0% 20% drag airplane level ugliness drag model will suffer function ugliness flux U machine ugliness flux measure amount ugliness being transmitted machine measured units ughs/stareradian An ugh elementary quantum ugli ness stareradian measure visual solid angle U can determined integrating local ugliness flux u over surface sphere containing model2n2rr JU/R2d&d4 Cdu ugliness drag coefficient model determined ugliness flux U use following formula CduKoeUI2 Ko observer constant based age preferences eyesight favorite color observer level available light point can sense growing protest people persist building models have bizarre shapes color 1 schemes ask does Continued page 139 March 1983 59 N Fig 5 Gloss Divergence has some unusual prop erties Models low end scale frequently good stable fliers Fig 6 model dangerously unstable despite generous tail surfaces forward CG location culprit Gloss Divergence wruu Iruus young mini ano wnau uues ne KflOW war resi us gan ruts purure Ut teorge rerryman years ago appears earliest successful practitioners subtle art science Pseudoserodynamicswhlch thoroughly examined article 6 Fig 7 An example ugly-shiny airplane Its bound good flier Fig 8 Weirdness Force yet proved may potent produce good fliers BALSA SHEETS 36 1/16x2 1056290 3/32 2 10 p6398 1/8 2 10 ph385 3/16 2 10 skI435 1/4 2 10 pk499 1/163 10 pk 330 3/32 3 10 pk390 1/8 /3 10 pk480 3/16 3 5 pk275 1/4 3 5 phI325 5/16 3 5 pk350 3/8 3 5 pk395 5/2 3 5 pk495 3/4 32 pk280 1 s32p6350 1/18 4 10 pk520 3/32 4 5 ph315 1/9 a4 6 pk360 3/16n4 5561415 1/4 a4 5 skI495 LIGHT 4 6 LB 36 1/16s3lOpk430 3/32 310 pk490 1/8 s310 ph580 3/16 35 pk325 1/4 s39 pk375 3/8 35 pk495 1/2 n35 pk598 MATCHED SHEETS 42 3/32 44pk399 1/8 sd4pk429 3/16 445k459 1/4s44pk499 SALSASHEETS 46 1/16s310 ph440 3/32-5310 pk515 1/9 s310 pk635 3/16s35skI369 1/4 38pk425 3/8 35phI558 1/2 34ph960 1164lOphI680 3/32a 45pk419 1/6s45pk475 3/1645pk547 1/445ph600 T8AILING EDGE 36 14 xl6 pk200 6/1611/46pk250 3/S 1-1/2 6 ph 295 1/2 s2 4 ph299 BALSASHEETS 30 1/16 s310 pk275 3/32 310 pk325 1/8 s310 pk405 1/16x410 phI430 3/32 410 pk504 1/8s410 pk590 BALSA TRIANGLES 36 1/41/4 10 pk250 3/9 3/8 10 ph225 1/2 s 1/2 10 EkI 4 50 3/4a 3/4 5 pL209 1 15 ph275 BALSA STICKS 36 1/16s1/4170ph180 3/32 1/420 pk190 1/8 sq20 ph140 i/S sl/420 phI195 1/Sn1/220 pk315 3/16 sq20 pk215 1/4 sq20 ph315 1/4 sl/220 ph430 3/8 5910 pk275 3/8 s 1/210 pk315 1/2 sq10 ph360 48 STICKS ADO 25% PINESTICKS 36 1/8 sq10 pk125 1/8 si/A10 ph155 1/8 3/810 ph200 3/16 sq10 ph165 1/4 as110 014255 1/4 s3/8 10 pk295 3/8 sq10 pk320 48 STICKS ADD 25% BIRCH DOWELS 36~ 1/810pk85 3/1610pls109 1/410ph140 POPLAR LITE PLY 48 1/86 2 ph300 1/8s12 2 ph600 3ply 8IRCH PLYWOOD 48 1/32s12l ph425 1/16s121 ph435 1/8 s12 1 pk450 PLY BIRCH48 3/32s121ph520 1/8 a12 1 501585 3/16x121 pk585 1/4s12 1 pk600 FUN FLI 40STAR STIKLONE STARCOMING SOON raIner~vSTARRAT jSC Combat 51495 KWIKSTAR $2495 00 cke 500 51 SI/aS IS 40Eqoe151SSALE 51 Spas4DYsqoe48 Spos35 Enqos $1995Si 995$1895Fos Comoa54200 P55 25 9CS4895Fos 1 9858C5400 Kits feature foam wings balsa ply fuse Machine cut parts rugged VeryFos 4068RC5700 quick assembly outstanding value. Choice trike gear Bail dragger.Fox 45 668C5700 Fox Eagle III7500 Rdey Woolens UC Combat Shadom foam Cores-$t95 accept Visa Master Charge personal checks COD pay UpS 1/2Afoam Cores$495Handling charge -$300 add $200 COD 5% las TX US Carrency accelerator anyjoint made CyA causes instant cure also eliminates fumes given off glue cures seem have allergic reaction fumes can eliminate problem way drawbacks CyA fact instantly bond fingers other work Up until recently answer worry apart new product called Z-7 Debonder softens almost fast acetone dissolves model airplane cement will take CyA fingers will remove other places does belongsuch workbenches desks floors tools etc use CyA should have debonder shop summary thin CyAs should wicked intojoints held place thicker CyAs should used joint made Unused CyA should kept refrigerator freezer extend its use ful life must allowed return room temperature before opening use use accelerator cause instant cure makes thicker CyAs quite useful making joints building fillets filling really large voids debonder available unstick fingers other things inadvertently joined serious drawback CyAs fact bonding power deterio rates age end 110 years have lost over half strength subject glues adhesives com plex their-applications almost limitless obvious article has little outline mate rials techniques available Excellent information obtainable manufacturers products men tioned list given theend article Remember adhesives glues cements dangerous used care lessly model airplane cements burn almost well glow fuel epoxies CyAs give off fumes cure should avoided cases before using product read instructions package follow Ace RC Inc Box 51 IF Higginsville MO 64037 Cyano Set Ambroid Company Inc PO Box 1089 Taunton MA 02780 Ambroid cement Borden Inc Dept CP Columbus OH 43215 Elmers glue Carl Goldberg Models 4735 West Chicago Ave Chicago II 60651 Jet Super-Jet Franklin Glue Co 2020 Bruck Columbus OH 43207 Titebond Hobbypoxy Products Pettit Paint Co PO Box 378 Rockaway NJ 07866 tHobbypoxy Pacer Technology & Resources Inc 1600 Dell Ave Campbell CA 95008 Zap Zap-AGap Zip Kicker Z-7 Debonder Satellite City PO Box 836 Simi CA 93062 Hot Stuff Super-T Hot Shot Testors Corp 620 Buckbee St Rockford IL 61101 Testors cement Pseudoaerodynamics/Wainfan Continued page 59 Weirdstrangie Mk 44 fly well everyone tells its ugly True think its ugly dont its creation Ugliness drag relativistic phenomenon student relativity can tell everything depends frame reference As long dont think its ugly its ugliness drag will reamin low works long truly believe model ugly however PERFECT COVERING MATERIAL FOR LARGE RIC MODELS 1 8 oz /sq yd Shnnkable Dope Easy apply Extremely strong doesn t run through like silk March 1983 139 Gluing/Randolph Continued page 56 66 90de 1 pd$585 3yds 81750 Syds 52750 ORDER DB8ECT Add 5100 HosdIin 5- tao ii ifosada JERRY NELSON & COMPANY OSlO San Maiso Asenus 6c,, Nesad 49509 102325-OhM DIstrIbutors & Dealers Welcomed Flyline Models 2820 Don Ave B-i 1 Fairfax Virginia 22931 USA Send 505 Fyline catalog lifE T LAKES ENDANNER Left GMP2001-R Regular Right GMP-2001-D IDeluxel Dealers Invited 5 Hoitay H -fl Wing Span 785 Wing Area 560 Sq A~14 SENSOAR glider HOBBY HORN Foclcisive HOBBY HORN Kit SENSOAR Glider kit high quality kit Machine cutsanded parts Select quality balsa spruce Detailed plans written instructions THERMAL SLOPE 05 ELECTRIC POWER VALUE PRICED 51500 OLD TtStR Kn7S Fall awd Partial Kits P & tI Semi Kilt Catibined tilh fall oiripWoOd ond ploit INos iitcl Wire lfitdaia etc Mat Note Theoe moy parchated fool oo temi kito plant write call pricca 1936Suoeeneer-t4-$tl 1938 Clipper ME l-72--$3g 1932Oullaire Splserltt$61 140 Ranger46 $27 t939Meroury72$t6 1g30 Mitt America 94-slg 1941Playboy Jr54529 1941 Playboy Sr 60940 1039Power Haase64-543 1940 Sailplano-7g- 974 1940So LaogS9$29 1939 Trenton Terror-OS 937 1939ZipperbaSag 1939 Korda Wakefield 44 $17 MIOIOAY MODEL CO Semi-kilo Combined w/olrip 1936 Flying Qauker94-949 1937 Qaukor Flash67t39 1937 Long Cabin79S42 1937 Air CbieE01$40 STRUCKS 1940 24 Span 839 Sq ruler SEMI KIT Plan Inci --$3390 N 5WCombo Pall Kit- --$6350 SCALE PLANS nd DRAWINGS 5 50 HEINKEL HE 1500 02 62s $1005 SHIPPING ANO HANOLINO 04 Page CATALOGUE Up ta $809 add $13$209 PP/tat Glatt $891 $2000 add $225A copy will toot $2001 Ia $4500 add $300 free regaetlod $4501 10 $7000 add $350 ardor over $7000 add $400 BBY HORN CA Addretares add 65 100 0thabby specialliesco Send ItO Visa/MCp-cEop15173 Moran Street A] Check fallow up 10 30 Row 2212 days check cleoranceWestminster Ce 92083 COO Exact Charges g 893 9311 Hdl Gash Oolv UPS] 4 8901203 140 Model Aviation USA ELECTRONIC DIGITAL TACHOMETERS GMP-2001 -R 2001 -D Visible Visible display ondisplay Visible low batteryVisible low battery displaydisplay 2 Bladed only2 & 3 Bladed props W liquid display% liquid display Crystal controlledCrystal controlled Catalog Available Ideal beginner well master flier CHARGEIT begin think looks shabby com parison other models its uglineses drag will increase sharply now probably convinced sure route fame success modeling world build exquis itely gorgeous model ever seen earth ugliness drag will low will slip effortlessly through air utterly outclassing mundane models flown other guys approach may indeed work prepared encounter prob lems Everything about airplane design inherently compromise reduction ugliness drag no exception Attempts eliminate ugliness drag may succeed cause model fall prey second major pseudoaerodynamic force dread gloss divergence Have ever noticed take time build carefully finished beau tiful model always manages crash damage itself least once before get trimmed flying well also seems necessary cut lovely finish somewhere order make modifica tion required get flying reason gloss divergence represented symbol Dg Gloss divergence function specific sparkle 5 model measured units gleams/lumen Gloss divergence itself usually quantified terms gloss induced negative static mar gin units precent chord Thus model has Dg 5% aft allowable CG will moved forward 5% chord classical aero dynamic theory says will forward limit may also moved aft leads ever-narrowing region stability illustrated plots below Dg TAIL SIZE S STABLE 6 0 $9d CD UNSTABLEUNSTABLE C 0 Gloss divergence manifests itself pitching rolling moment causes model stall dive ground spiral seems happen pretty airplanes Ugly ones may fly very well usual reasonably stable Most trainers square ugly stable hard get anything fly straight level good case point gloss divergence horrendous flight characteristics really good exact-scale models airplanes certainly suffering ugliness drag problems since among beautiful creations modeling world Nevertheless seem have tendency violently assault ground slightest provocation goes entirely against modelers credo machines look right fly wrong order make Scale models fly properly modelers must usually increase dihedral tail area order improve stability reason must obvious viewed light pseudoaerodynamic theory increase aero dynamic stability required overcome pseudoaerodynamic instability induced gloss divergence tendencies model some evidence certain mod elers have already discovered gloss diver gence Matte finishes becomingpopular Scale warbirds Bob White winning Rubber Free Flight ships uses deglos sing agent finishes Could people instinctively attempt ing minimize gloss divergence Obviously designing competitive model modeler must attempt walk thin line between excessive ugliness drag excessive gloss divergence general will increase other decreases important maddening compromises inherent MODELING PRODUCTS INC DEPT U PO BOX 818 STOWN PA 19484 37-1231 ELECTRIC RETRACTS GIEZENDANNER Two Time World Champion REGULAR RETRACTS 5/32 Pattern- Up 10 lbs HEAVY DUTY RETRACTS 3/16 Scale -10 18 lbs EXTRA HEAVY DUTY RETRACTS 1/4 Big Ones 18 50 lbs retract Slip Clutch preMent jamming stripping gears MANNU VIIL I NLII AU -015 1981-82 World R/C Aerobatic Champi Winner 7 consacutive Las Vegas Tournament Champions Shown above Giezendanner GMP 2001 -D Digital Tachometer Yes have Giezendanner Wipers 3 Bladed Low-Noise Glass Filled Props INTRODUCING NEW IMPROVED PERMAGLOSS New Permagloss Coverite dealers shelves right now package looks same top surface 4 coats paint still has realistic fabric finish resistance scuffing puncturing identical original ts similarities end CLAJ c7QZZ 147 LIGHTER Years ago lightened up Super Coverite now weve done same Permagloss 147% lighter Permagloss compares plastic films As soon feel youll notice its lighter thinner means seams will far less noticeable going around compound curves will easier before BETTER ADHESION Permagloss Coverite now comes new adhesive coating provides superior sticking qualities Balsarite will particularly noticeable sheeted surfaces bubbling recurring problem Use same techniques before solid surfaces lower temperature iron 2500F.2750F massage just heated area damp cloth open areas pull fabric tight can raise temperature 3500F.3750F allow 3 seconds heat penetration Irons preferrable heat guns never never use heat gun sheeted surface BOUNCE QUARTER OFF HER BELLY New Permagloss draws up tighter before About same Super Coverite will big help covering large surface including Quarter-Scalers oversized gliders follow instructions especially regarding grain direction ironing will achieve drum-tight skin will offer excellent resistance sagging 14 COLORS White brite red dark red lite blue dark blue lemon yellow cub yellow orange aluminum black olive drab sunglow orange sunglow yellow cream ATTENTION BEGINNERS youre just getting started youre sure type covering use think about Plastic film looks great dealers store its slick shiny surface will scratch during application youre very careful Worse still two landings experienced flyers get scuff marks tears double meaning intended Whats ironing plastic film have sure overheat because film burns 3000F other hand Permagloss Coverite wont burn until get over 4000F mention its lengendary strength cant hardly make dent n t Scuffs scratches virtually non ex stant s cover ng can truly stand up beg nner s early flight training CVERITE L 420 BABYLON ROAD HORSHAM PENNSYLVANIA 19044 USA model airplane design always desire make model beautiful its beauty turns out fatal flaw DRAG course really masochist can build ugly shiny airplane get zapped both sides optimization airplane requires take account ugliness drag gloss divergence configuration changes required compensate Typically increasing gloss divergence requires increase tail size increase tail size will conquer gloss-divergence-induced instability model cost increased skin friction drag same time increase gloss will cause ugliness drag model decrease curve total aircraft drag vs specific sparkle becomes concave dis playing clearly defined optimum pointif plot made constant stability margin taking account variation tail size specific sparkle designer must usually approach optimum empirically since pseudoaero dynamic parameters extremely difficult S measure quantitatively harder predict reasonable degree accuracy some modelers author cluded believe unconventional configurations may lead higher perform ance belief has led postulation third yet hypothetical pseudoaero dynamic quantity weirdness force As postulated weirdness force directly pro portional strangeness model measured boggles/glance may act almost direction Weirdness forces may help fight ugliness drag gloss diver gence both existence weird ness force has yet rigorously proven although research progress has shown promising results oddball models fly very well despite bizzare appearance would seem likely some unknown effect helping along George Perryman probably first modeler make sustained effort exploit weirdness force competition closing can seen pseudo GIANT SCALE & SPORT PLANS SETS & KITS order contains concse construction manual Partial kits include precut 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Fig 1 model high ugliness drag Such drag cannot measured easily -y Fig 2 model low ugliness drag Ugliness drag previously undocumented Barnaby Wainfan Have ever wondered basically similar model aircraft fly differ ently author takes in-depth look related subjects results may startle youIllustrations John Hunton MODELERS just like airplane design ers perpetually exploring fascinat ing gray area between art science much both process creating model attractive flies well science aerodynamics well documented elsewhere purpose article shed some light less well documented forces affecting model airplane Much airplane model design rigidly scientific configuration airplane determined its design mission mission specifies size wing loading airfoil characteristics etc air plane must have order its job As aerodynamicist can tell performance airplane determined such parameters wing loading aspect ratio lift coefficient Reynolds Number span efficiency others effects of scientifically deter mined quantities can written down form set graphs tables performance airplane can determined What graphs say airplane will Period Modelers instinctively dissatisfied rigid analytical view craft something aesthetically displeasing about mechanistic point view need design good model set tables graphs no room individual self-expression much part enjoyment modeling no room innovation no room art modeler tends look things subjective way will tell looks right itwillflyright Usuallyitdoes Nicely proportioned models balanced eye-pleasing lines usually fly very well other hand ugly awkward ships rarely None can determined con sulting tables graphs An perplexing effect may observed two modelers build ma chines same design nero dynamicists point view two planes theoretically identical should fly identically dont prettier model always seems fly better drab Obviously aerodynamicists have overlooked something order understand what has overlooked must expand 58 Model Aviation Fig 3 non-sleek model just seems go slow wallow over sky -y Fig 4 Sleek airplanes lust go Waster nonsleek counterparts speed study model design previously unexplored area pseudoaerodynamics After much investigation previously un documented component drag model has identified compo nent related directly appearance model known ugliness drag described ugliness drag coeffi cient Cdu normalized re spect area dynamic pressure exactly same way drag coefficients defined classical aerodynamic theory Cdu direct function lines finish model Cdu 0du GLOSS SLEEKNESS Although ugliness drag cannot easily measured apparently constitutes somewhere between 0% 20% drag airplane level ugliness drag model will suffer function ugliness flux U machine ugliness flux measure amount ugliness being transmitted machine measured units ughs/stareradian An ugh elementary quantum ugli ness stareradian measure visual solid angle U can determined integrating local ugliness flux u over surface sphere containing model2n2rr JU/R2d&d4 Cdu ugliness drag coefficient model determined ugliness flux U use following formula CduKoeUI2 Ko observer constant based age preferences eyesight favorite color observer level available light point can sense growing protest people persist building models have bizarre shapes color 1 schemes ask does Continued page 139 March 1983 59 N Fig 5 Gloss Divergence has some unusual prop erties Models low end scale frequently good stable fliers Fig 6 model dangerously unstable despite generous tail surfaces forward CG location culprit Gloss Divergence wruu Iruus young mini ano wnau uues ne KflOW war resi us gan ruts purure Ut teorge rerryman years ago appears earliest successful practitioners subtle art science Pseudoserodynamicswhlch thoroughly examined article 6 Fig 7 An example ugly-shiny airplane Its bound good flier Fig 8 Weirdness Force yet proved may potent produce good fliers BALSA SHEETS 36 1/16x2 1056290 3/32 2 10 p6398 1/8 2 10 ph385 3/16 2 10 skI435 1/4 2 10 pk499 1/163 10 pk 330 3/32 3 10 pk390 1/8 /3 10 pk480 3/16 3 5 pk275 1/4 3 5 phI325 5/16 3 5 pk350 3/8 3 5 pk395 5/2 3 5 pk495 3/4 32 pk280 1 s32p6350 1/18 4 10 pk520 3/32 4 5 ph315 1/9 a4 6 pk360 3/16n4 5561415 1/4 a4 5 skI495 LIGHT 4 6 LB 36 1/16s3lOpk430 3/32 310 pk490 1/8 s310 ph580 3/16 35 pk325 1/4 s39 pk375 3/8 35 pk495 1/2 n35 pk598 MATCHED SHEETS 42 3/32 44pk399 1/8 sd4pk429 3/16 445k459 1/4s44pk499 SALSASHEETS 46 1/16s310 ph440 3/32-5310 pk515 1/9 s310 pk635 3/16s35skI369 1/4 38pk425 3/8 35phI558 1/2 34ph960 1164lOphI680 3/32a 45pk419 1/6s45pk475 3/1645pk547 1/445ph600 T8AILING EDGE 36 14 xl6 pk200 6/1611/46pk250 3/S 1-1/2 6 ph 295 1/2 s2 4 ph299 BALSASHEETS 30 1/16 s310 pk275 3/32 310 pk325 1/8 s310 pk405 1/16x410 phI430 3/32 410 pk504 1/8s410 pk590 BALSA TRIANGLES 36 1/41/4 10 pk250 3/9 3/8 10 ph225 1/2 s 1/2 10 EkI 4 50 3/4a 3/4 5 pL209 1 15 ph275 BALSA STICKS 36 1/16s1/4170ph180 3/32 1/420 pk190 1/8 sq20 ph140 i/S sl/420 phI195 1/Sn1/220 pk315 3/16 sq20 pk215 1/4 sq20 ph315 1/4 sl/220 ph430 3/8 5910 pk275 3/8 s 1/210 pk315 1/2 sq10 ph360 48 STICKS ADO 25% PINESTICKS 36 1/8 sq10 pk125 1/8 si/A10 ph155 1/8 3/810 ph200 3/16 sq10 ph165 1/4 as110 014255 1/4 s3/8 10 pk295 3/8 sq10 pk320 48 STICKS ADD 25% BIRCH DOWELS 36~ 1/810pk85 3/1610pls109 1/410ph140 POPLAR LITE PLY 48 1/86 2 ph300 1/8s12 2 ph600 3ply 8IRCH PLYWOOD 48 1/32s12l ph425 1/16s121 ph435 1/8 s12 1 pk450 PLY BIRCH48 3/32s121ph520 1/8 a12 1 501585 3/16x121 pk585 1/4s12 1 pk600 FUN FLI 40STAR STIKLONE STARCOMING SOON raIner~vSTARRAT jSC Combat 51495 KWIKSTAR $2495 00 cke 500 51 SI/aS IS 40Eqoe151SSALE 51 Spas4DYsqoe48 Spos35 Enqos $1995Si 995$1895Fos Comoa54200 P55 25 9CS4895Fos 1 9858C5400 Kits feature foam wings balsa ply fuse Machine cut parts rugged VeryFos 4068RC5700 quick assembly outstanding value. Choice trike gear Bail dragger.Fox 45 668C5700 Fox Eagle III7500 Rdey Woolens UC Combat Shadom foam Cores-$t95 accept Visa Master Charge personal checks COD pay UpS 1/2Afoam Cores$495Handling charge -$300 add $200 COD 5% las TX US Carrency accelerator anyjoint made CyA causes instant cure also eliminates fumes given off glue cures seem have allergic reaction fumes can eliminate problem way drawbacks CyA fact instantly bond fingers other work Up until recently answer worry apart new product called Z-7 Debonder softens almost fast acetone dissolves model airplane cement will take CyA fingers will remove other places does belongsuch workbenches desks floors tools etc use CyA should have debonder shop summary thin CyAs should wicked intojoints held place thicker CyAs should used joint made Unused CyA should kept refrigerator freezer extend its use ful life must allowed return room temperature before opening use use accelerator cause instant cure makes thicker CyAs quite useful making joints building fillets filling really large voids debonder available unstick fingers other things inadvertently joined serious drawback CyAs fact bonding power deterio rates age end 110 years have lost over half strength subject glues adhesives com plex their-applications almost limitless obvious article has little outline mate rials techniques available Excellent information obtainable manufacturers products men tioned list given theend article Remember adhesives glues cements dangerous used care lessly model airplane cements burn almost well glow fuel epoxies CyAs give off fumes cure should avoided cases before using product read instructions package follow Ace RC Inc Box 51 IF Higginsville MO 64037 Cyano Set Ambroid Company Inc PO Box 1089 Taunton MA 02780 Ambroid cement Borden Inc Dept CP Columbus OH 43215 Elmers glue Carl Goldberg Models 4735 West Chicago Ave Chicago II 60651 Jet Super-Jet Franklin Glue Co 2020 Bruck Columbus OH 43207 Titebond Hobbypoxy Products Pettit Paint Co PO Box 378 Rockaway NJ 07866 tHobbypoxy Pacer Technology & Resources Inc 1600 Dell Ave Campbell CA 95008 Zap Zap-AGap Zip Kicker Z-7 Debonder Satellite City PO Box 836 Simi CA 93062 Hot Stuff Super-T Hot Shot Testors Corp 620 Buckbee St Rockford IL 61101 Testors cement Pseudoaerodynamics/Wainfan Continued page 59 Weirdstrangie Mk 44 fly well everyone tells its ugly True think its ugly dont its creation Ugliness drag relativistic phenomenon student relativity can tell everything depends frame reference As long dont think its ugly its ugliness drag will reamin low works long truly believe model ugly however PERFECT COVERING MATERIAL FOR LARGE RIC MODELS 1 8 oz /sq yd Shnnkable Dope Easy apply Extremely strong doesn t run through like silk March 1983 139 Gluing/Randolph Continued page 56 66 90de 1 pd$585 3yds 81750 Syds 52750 ORDER DB8ECT Add 5100 HosdIin 5- tao ii ifosada JERRY NELSON & COMPANY OSlO San Maiso Asenus 6c,, Nesad 49509 102325-OhM DIstrIbutors & Dealers Welcomed Flyline Models 2820 Don Ave B-i 1 Fairfax Virginia 22931 USA Send 505 Fyline catalog lifE T LAKES ENDANNER Left GMP2001-R Regular Right GMP-2001-D IDeluxel Dealers Invited 5 Hoitay H -fl Wing Span 785 Wing Area 560 Sq A~14 SENSOAR glider HOBBY HORN Foclcisive HOBBY HORN Kit SENSOAR Glider kit high quality kit Machine cutsanded parts Select quality balsa spruce Detailed plans written instructions THERMAL SLOPE 05 ELECTRIC POWER VALUE PRICED 51500 OLD TtStR Kn7S Fall awd Partial Kits P & tI Semi Kilt Catibined tilh fall oiripWoOd ond ploit INos iitcl Wire lfitdaia etc Mat Note Theoe moy parchated fool oo temi kito plant write call pricca 1936Suoeeneer-t4-$tl 1938 Clipper ME l-72--$3g 1932Oullaire Splserltt$61 140 Ranger46 $27 t939Meroury72$t6 1g30 Mitt America 94-slg 1941Playboy Jr54529 1941 Playboy Sr 60940 1039Power Haase64-543 1940 Sailplano-7g- 974 1940So LaogS9$29 1939 Trenton Terror-OS 937 1939ZipperbaSag 1939 Korda Wakefield 44 $17 MIOIOAY MODEL CO Semi-kilo Combined w/olrip 1936 Flying Qauker94-949 1937 Qaukor Flash67t39 1937 Long Cabin79S42 1937 Air CbieE01$40 STRUCKS 1940 24 Span 839 Sq ruler SEMI KIT Plan Inci --$3390 N 5WCombo Pall Kit- --$6350 SCALE PLANS nd DRAWINGS 5 50 HEINKEL HE 1500 02 62s $1005 SHIPPING ANO HANOLINO 04 Page CATALOGUE Up ta $809 add $13$209 PP/tat Glatt $891 $2000 add $225A copy will toot $2001 Ia $4500 add $300 free regaetlod $4501 10 $7000 add $350 ardor over $7000 add $400 BBY HORN CA Addretares add 65 100 0thabby specialliesco Send ItO Visa/MCp-cEop15173 Moran Street A] Check fallow up 10 30 Row 2212 days check cleoranceWestminster Ce 92083 COO Exact Charges g 893 9311 Hdl Gash Oolv UPS] 4 8901203 140 Model Aviation USA ELECTRONIC DIGITAL TACHOMETERS GMP-2001 -R 2001 -D Visible Visible display ondisplay Visible low batteryVisible low battery displaydisplay 2 Bladed only2 & 3 Bladed props W liquid display% liquid display Crystal controlledCrystal controlled Catalog Available Ideal beginner well master flier CHARGEIT begin think looks shabby com parison other models its uglineses drag will increase sharply now probably convinced sure route fame success modeling world build exquis itely gorgeous model ever seen earth ugliness drag will low will slip effortlessly through air utterly outclassing mundane models flown other guys approach may indeed work prepared encounter prob lems Everything about airplane design inherently compromise reduction ugliness drag no exception Attempts eliminate ugliness drag may succeed cause model fall prey second major pseudoaerodynamic force dread gloss divergence Have ever noticed take time build carefully finished beau tiful model always manages crash damage itself least once before get trimmed flying well also seems necessary cut lovely finish somewhere order make modifica tion required get flying reason gloss divergence represented symbol Dg Gloss divergence function specific sparkle 5 model measured units gleams/lumen Gloss divergence itself usually quantified terms gloss induced negative static mar gin units precent chord Thus model has Dg 5% aft allowable CG will moved forward 5% chord classical aero dynamic theory says will forward limit may also moved aft leads ever-narrowing region stability illustrated plots below Dg TAIL SIZE S STABLE 6 0 $9d CD UNSTABLEUNSTABLE C 0 Gloss divergence manifests itself pitching rolling moment causes model stall dive ground spiral seems happen pretty airplanes Ugly ones may fly very well usual reasonably stable Most trainers square ugly stable hard get anything fly straight level good case point gloss divergence horrendous flight characteristics really good exact-scale models airplanes certainly suffering ugliness drag problems since among beautiful creations modeling world Nevertheless seem have tendency violently assault ground slightest provocation goes entirely against modelers credo machines look right fly wrong order make Scale models fly properly modelers must usually increase dihedral tail area order improve stability reason must obvious viewed light pseudoaerodynamic theory increase aero dynamic stability required overcome pseudoaerodynamic instability induced gloss divergence tendencies model some evidence certain mod elers have already discovered gloss diver gence Matte finishes becomingpopular Scale warbirds Bob White winning Rubber Free Flight ships uses deglos sing agent finishes Could people instinctively attempt ing minimize gloss divergence Obviously designing competitive model modeler must attempt walk thin line between excessive ugliness drag excessive gloss divergence general will increase other decreases important maddening compromises inherent MODELING PRODUCTS INC DEPT U PO BOX 818 STOWN PA 19484 37-1231 ELECTRIC RETRACTS GIEZENDANNER Two Time World Champion REGULAR RETRACTS 5/32 Pattern- Up 10 lbs HEAVY DUTY RETRACTS 3/16 Scale -10 18 lbs EXTRA HEAVY DUTY RETRACTS 1/4 Big Ones 18 50 lbs retract Slip Clutch preMent jamming stripping gears MANNU VIIL I NLII AU -015 1981-82 World R/C Aerobatic Champi Winner 7 consacutive Las Vegas Tournament Champions Shown above Giezendanner GMP 2001 -D Digital Tachometer Yes have Giezendanner Wipers 3 Bladed Low-Noise Glass Filled Props INTRODUCING NEW IMPROVED PERMAGLOSS New Permagloss Coverite dealers shelves right now package looks same top surface 4 coats paint still has realistic fabric finish resistance scuffing puncturing identical original ts similarities end CLAJ c7QZZ 147 LIGHTER Years ago lightened up Super Coverite now weve done same Permagloss 147% lighter Permagloss compares plastic films As soon feel youll notice its lighter thinner means seams will far less noticeable going around compound curves will easier before BETTER ADHESION Permagloss Coverite now comes new adhesive coating provides superior sticking qualities Balsarite will particularly noticeable sheeted surfaces bubbling recurring problem Use same techniques before solid surfaces lower temperature iron 2500F.2750F massage just heated area damp cloth open areas pull fabric tight can raise temperature 3500F.3750F allow 3 seconds heat penetration Irons preferrable heat guns never never use heat gun sheeted surface BOUNCE QUARTER OFF HER BELLY New Permagloss draws up tighter before About same Super Coverite will big help covering large surface including Quarter-Scalers oversized gliders follow instructions especially regarding grain direction ironing will achieve drum-tight skin will offer excellent resistance sagging 14 COLORS White brite red dark red lite blue dark blue lemon yellow cub yellow orange aluminum black olive drab sunglow orange sunglow yellow cream ATTENTION BEGINNERS youre just getting started youre sure type covering use think about Plastic film looks great dealers store its slick shiny surface will scratch during application youre very careful Worse still two landings experienced flyers get scuff marks tears double meaning intended Whats ironing plastic film have sure overheat because film burns 3000F other hand Permagloss Coverite wont burn until get over 4000F mention its lengendary strength cant hardly make dent n t Scuffs scratches virtually non ex stant s cover ng can truly stand up beg nner s early flight training CVERITE L 420 BABYLON ROAD HORSHAM PENNSYLVANIA 19044 USA model airplane design always desire make model beautiful its beauty turns out fatal flaw DRAG course really masochist can build ugly shiny airplane get zapped both sides optimization airplane requires take account ugliness drag gloss divergence configuration changes required compensate Typically increasing gloss divergence requires increase tail size increase tail size will conquer gloss-divergence-induced instability model cost increased skin friction drag same time increase gloss will cause ugliness drag model decrease curve total aircraft drag vs specific sparkle becomes concave dis playing clearly defined optimum pointif plot made constant stability margin taking account variation tail size specific sparkle designer must usually approach optimum empirically since pseudoaero dynamic parameters extremely difficult S measure quantitatively harder predict reasonable degree accuracy some modelers author cluded believe unconventional configurations may lead higher perform ance belief has led postulation third yet hypothetical pseudoaero dynamic quantity weirdness force As postulated weirdness force directly pro portional strangeness model measured boggles/glance may act almost direction Weirdness forces may help fight ugliness drag gloss diver gence both existence weird ness force has yet rigorously proven although research progress has shown promising results oddball models fly very well despite bizzare appearance would seem likely some unknown effect helping along George Perryman probably first modeler make sustained effort exploit weirdness force competition closing can seen pseudo GIANT SCALE & SPORT PLANS SETS & KITS order contains concse construction manual Partial kits include precut wing ribs luselag s prebent landing gear Full kits include everytl plus strip Travel Air D 4000 J B Special MK 4 convertible 84 Monoplane 78 Biplane Weighs 18 lbs Low Wing Biplane Er Parasol Pla,s $21 95r Plans $2195 Partial Kit $8495j- Either Both Partial Kit $9495 Fall Kit $18495 Full Kit $19495 Travel Air 2000 i05 classic Scale Biplane Wt 231bs Pla,s $2295Partial Kit $9850Full Kit $19850 Travel Air 4000 99 Radial Eng classic Biplane 23 lbs Pla,s $2295Partial Kit $9995040 Kit $21400 Fnkker DVII 88 German WWI Fighter Biplane 23 lbs Plans 2495Partial Kit $10995Full Kit $20950 Sopwith Tripehound 80 WWI Triplane 17 lbs Plans $2195Partial Kit $10995Full Kit $21995 Sopwith Pup WWI Biplane 16-17 lbs Plans $2195Partial Kit $9950Full Kit $19850 WACO uPF-7 90 Biplane 23 lbs Plans $2395 Airplanes Landing Gear 2 wire forned o,ly $995 hipping Assembled ready toinstall $1995 shipping Wheel Pants models add $5 Cabames$995 hipping Fokker Cabares$1495 hipping Ordering information orders shipped us Parcel Post Please add $3 shipping plans $10 kits Make checks payable Jerry BebrensFor lastest service send Postal money order hank check Sorry no COD will accepted Se,d nail orders BEHRENS PLAN SERVICE 3127 Healy Ave. Far Rockaway NV 11691 Phone 212 337-6987Allow 4 6 weeks br delivery March 1983 141 SUPER MINI-BOY VIDtO MINIATURE AIRCRAFT SUPPLY BRINGS YOU ANOTHER HELICOPTER FIRST Professionally produced video takes workshop professionally build set up flight trim mini-boy includes step step building parts Iden tIfication mechanical operational walk through radio installation balancing bench setup operational flight trimming aerobatics vIdeo better having someone else build Mini-Boy Video produced Mike Mas National Helicopter Champion Available ary 1963 BETA VHS WE CAN SUPPLY ALL OF YOUR HELICOPTER NEEDS AT UNBEATABLE PIICESI Engines Worlds Strongest Epoxy Glues Radios MIni-Boy Competition Pack Mufflers Training Aids Custom Carburators Video Cassettes Gyros CompetItor Symetrical Main 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certainly finest-flying kits market Next Peck Lacey M-10 mentioned survey other model great flying model Flyline 2820 Dorr Ave B-I Fairfax VA 22031 Finally last least Peck Polymers PO Box 2498 La Mesa CA 92041 presently selling larger Rubber Scale kits has best complete line stuff rubber CO-2 builder know way books worlds top Peanut plans kits buck brings hope others have good bad experiences kits will write us share experiences subject plans Dave Diels PO Box 101 Woodville OH 43469 has lineup nicely-drawn Peanut plans states also available 18-in span -in foot ones sent feature laminated wingtips tail outlines might give new modeler some trouble attached instruc tion sheet separate Xerox cut-out 142 Model Aviation ORDER YOUR VIDEO NOW 5 plus Shipping