Control Line Aerobatics Ted Fancher HELLO again Stunt fans swear tween trying get Rena ship finished its now June 30th have just sprayed clear over Trim-Kate United Airlines insisting actually flying paycheck beginning wonder Id ever get chance get thing writ So barring Apple turning cider goes After meet Eugene OR over last month hanging around waiting return trip noticed sharp young flier about wham comment ed last month Randy Schultz still contest site apparently practicing went out observe doing dis covered perfect subject column During competition over heard Randy Paul Walker discussing trim problem Randys ship transitioning insides outsides vice versa aircraft would yaw notice ably accompanying line-tension problems Stunt Glossary An aircraft capable movement about three axes roll pitch yaw Roll movement about lateralfore-aft axis wing tips going up down pitch movement about horizontalwing tip-to-wing tipaxis nose going up down yaw movement about vertical axis nose going right left Discussion inspection Randys ship revealed beautifully built properly balanced leadouts perhaps little far forward ballpark No readily-apparent reason problem worked leadouts however surprised discover controls set up front leadout Up line Upon inquiring learned done pur pose intended counteract gyroscopic precession Further discus sian disclosed practice nearly universal Northwest rently RELATIVE WIND ASCENDING BLADE BLACK DESCENDING BLADE WHITE TL THRUST LINE Ted wants tell us about P-Factor affects maneuvering trim Stunters quite widespread throughout country Wrong methanol breath Gyroscopic precession term ban died about Stunt circles few years back Al Rabe magnificent semi-scale Mustangs Bearcats Sea Furies threatened dominate na T /1 100 F G LEVEL FLIGHT / / 200 FIG 2 100 AofA tional competition scene According theory propounded Al mass spinning propeller acted gyro scope mounted front plane gyroscope displaced its plane rotation propagates force 900 Continued page 169 Two overseas Piotr Zawada Poland wins lot Eastern Europe original L-19 L also did well 1982 CL World Champs Swedenplaced 16th Englands Mike Weaver flies John Lynch-designed Eagle R Note hole left flap 78 Model Aviation o0I 00 Kevin Capitaneili Fairfield NJ justifiably proud plane f lies well Its Supertlgre 60 also won Best Finish award ate meet Edison NJ June 1984 Sixtyounce craft has dope finish uses solid control lines ENEAE~ hinge allows control D I1IIVLV& rface removal tools lost puns problems fr PATENT painting repair PENDINGcovering transportation storage etc Scale Appearance InsertSimple Assembly 3 SIZES No Slots No Pins Rotate 38-6 $445 12-6 $495 years ago Bread now $100 loaf 049 kit out world So comments Print wish Some recent correspondence has quite interesting thoughtprovokingbut cant print Dont let deter sending observations opinions Speed need inputs modelers possible can best figure out what readers may interested Keep cards letters photos coming Gene Hempel 301 N Yale Dr Gar land TX 75042 CL AerobatlcslFancher Continued page 78 applied force such manner cause yaw right air craft pitched up left pitched down thereby increasing line ten sion insides decreasing outsides examples column will consider model flying normal anti-clock wise flight battle insidious force Al devised two gimmicks First famous Rabe Rudder connected elevator apply right rudder outside maneuvers second front-Up leadout point rear Down leadout intent both cause ship yaw away pilot outside maneuvers thus neutral ize evil precession First let make clear defer no admiration accomplishments Al Rabe words Frank Sinatra did way way best ways ever once mentioned Bill Werwage handful Stunt Masters feel Al sits very comfortably same small list However. due respect Al gyroscopic precession effects real phenomenon way prop weighing under half ounce spinning modest rpms simply isnt significant trim problem three-to-four-pound mass moving 50 60 mph estimation classic example right solution wrong problem Als ships did have unique trim prob lem both devices clever solution However wasnt gyro scopic precession wit Als semiscale ships built substantial amounts dihedral Stunt Glossary Dihedral design concept wherein wing tips higher root wing Dihedral makes aircraft stable roll axis ie wing drops its ver tical lift component greater raised wing will therefore natu rally raise low wing thereby maintain ing wings-level attitude wing dihedral inherently stable posi tive-G maneuvers ie insides inherent ly unstable negative-G maneuvers ie outsides instability unpre dictable may manifest itself roll either left right What both Rabe Rudder front-Up line accomplished make inevitable roll predictable advan tageous Control Line pilot caus ing yaw accompanying roll away circle As further evidence devices best reserved bentwing birds reread Als own Mustunt arti cle American Aircraft Modeler February 1973 wherein has endless trouble making blamed rudder work basic simple straight-winged Stunter essence ends up almost no movement rudder Nuff said Well no really cause what really wanted discuss P Factor What may well asking yourself P-Factor direct answer discussion P-Factor reason should normally use rear Up line consider wig gly rudder should hook up work opposite Als ie right rudder insides Any real plane pilots addition Stunt jockeys probably nodding knowingly yourselves light dawns Please refer drawings RIDDE042 UL9LL R 1mm thick Boxed 16 oz rubber per boxSzes Price $1250 per box ppd USA32 _______1 1' TILKA ________8 WAKEFIEL $3895p.UPEnslsh3 FnshedFontEndanIdg ondFIyng 16 nst uctons Vey Connpl Send50te fo 1984/1985 catelog4 FAI Model Supply 57Torm9O51O U7i4cttijM ilk Incorporated 322 So Gallatin RdMadison TN 37115 615 868-6811 Mon thru Sat am 500 pm Ii Re p lace expensive throwaway dry cell transmitter battery recharg eable nickel cadmium battery Ready use Replaces Eveready 276 nIne volt dry cell battery Transmitter Ni-Cad Battery$3000 Transmitter Ni-Cad Charger$ 895 Battery/Charger Combo$3500 October1984 169 REPAIR SERVICE FOR HOBBY LOBBY EK LOGICTROL FUTABA T HOBBY SHACK ROYAL LINE AL RADIO SYSTEMSI FUTABA ROYAL ACCESSORIES FOR MOST RADIOSI ue BaIa 20134 STATE CERRITOS CA 90701 12131 860-1276 Regional Warehousing Sales Ollices iobout 310 N 5TH ST ST CHARLES Ii 60174 312 504-7616 Please send me ZAP/Chrissy posters $475 postpaid Enclosed check money order ________ Name Address 505 SiICIY GrOUP nierflOllOfld FRANK TIANO ENTERPRISES 628 ATE 32N NEW PALTZ NY 12561 914 6589906 StateZipI level flight both blades propel ler taking equal bites relative wind throughout entire revolution thrust therefore uniform points about prop disc see Figure 1 However whenever angle attack aircraft altered angle relative wind strikes given point aircraftincluding point prop discis changed similar fash ion see Figure 2 example lets say level flight given point prop taking 100 bite out relative wind will throughout entire 3600 propeller rotation thrust developed point prop cons tant throughout Now lets pitch up abruptly though entering Square Loop simplicitys sake lets say angle attack thus achieved also 100 sufficient gain lift needed rate turn desire Now look same given point propeller see what have done its angle tack therefore thrust delivers travels its 3600 its new relationship relative wind top bottom prop disc angle attack unchanged still 100 relative wind thus no change thrust However right ex treme descending side prop disc find prop now striking relative wind angle attack 200 thus producing much greater thrust level flight. approximately twice much greater surprise check out ever popular given point prop left extreme ascending side prop disc 100 change angle attack aircraft has total ly negated 100 bite prop blade propeller point acting flat plate producing no lift ie thrust Accepting points rotation between discussed simi larly affected linear fashion must conclude although thrust gener ated equal produced level flight center thrust therefore point thrust acts upon airframe has shifted significant distance starboard Since center drag has remained un changed net result will yaw left Solution Use aft Up line cause countering right yaw Result Right yaw cancels left yaw therefore will no yaw properly trimmed forces course reversed outside maneuvers Thus Down line can forward counteract outboard yaw Again right minus left equals zero feel P-Factor insig nificant force consider competitive Stunter has thrust-to-weight ratio ap proximately minor center thrust shift will fore have measurable impact veri fication ask real-plane pilot what does rudder pedals propdriven plane maintain heading climbing guessed right rudder last test real Doubting Thomases After practice flight CO aft because fuel has consumed changes line tension obvious series both inside outside Triangles will notice increased line tension outsides particularly top corners Also try some horizontal Hourglasses wherein line tension outside loops isnt being reduced high elevation vertical maneuver Again P-Factor will obvious last hint have Stunters hunt level flight What suppose happens leadouts far aft vain search line tension airplane yawing outward 100 tangent Oh guessed Vertical P-Factor work bottom half prop disc now producing thrust top half result plane quite logically wants climb Cute huh Ted Fancher 158 Flying Cloud Isle Foster City CA 94409 responding advertisers mention read about Model Aviation 170 Model Aviation p&~A#vP*t/ Owi&I
Edition: Model Aviation - 1984/10
Page Numbers: 78, 169, 170
Control Line Aerobatics Ted Fancher HELLO again Stunt fans swear tween trying get Rena ship finished its now June 30th have just sprayed clear over Trim-Kate United Airlines insisting actually flying paycheck beginning wonder Id ever get chance get thing writ So barring Apple turning cider goes After meet Eugene OR over last month hanging around waiting return trip noticed sharp young flier about wham comment ed last month Randy Schultz still contest site apparently practicing went out observe doing dis covered perfect subject column During competition over heard Randy Paul Walker discussing trim problem Randys ship transitioning insides outsides vice versa aircraft would yaw notice ably accompanying line-tension problems Stunt Glossary An aircraft capable movement about three axes roll pitch yaw Roll movement about lateralfore-aft axis wing tips going up down pitch movement about horizontalwing tip-to-wing tipaxis nose going up down yaw movement about vertical axis nose going right left Discussion inspection Randys ship revealed beautifully built properly balanced leadouts perhaps little far forward ballpark No readily-apparent reason problem worked leadouts however surprised discover controls set up front leadout Up line Upon inquiring learned done pur pose intended counteract gyroscopic precession Further discus sian disclosed practice nearly universal Northwest rently RELATIVE WIND ASCENDING BLADE BLACK DESCENDING BLADE WHITE TL THRUST LINE Ted wants tell us about P-Factor affects maneuvering trim Stunters quite widespread throughout country Wrong methanol breath Gyroscopic precession term ban died about Stunt circles few years back Al Rabe magnificent semi-scale Mustangs Bearcats Sea Furies threatened dominate na T /1 100 F G LEVEL FLIGHT / / 200 FIG 2 100 AofA tional competition scene According theory propounded Al mass spinning propeller acted gyro scope mounted front plane gyroscope displaced its plane rotation propagates force 900 Continued page 169 Two overseas Piotr Zawada Poland wins lot Eastern Europe original L-19 L also did well 1982 CL World Champs Swedenplaced 16th Englands Mike Weaver flies John Lynch-designed Eagle R Note hole left flap 78 Model Aviation o0I 00 Kevin Capitaneili Fairfield NJ justifiably proud plane f lies well Its Supertlgre 60 also won Best Finish award ate meet Edison NJ June 1984 Sixtyounce craft has dope finish uses solid control lines ENEAE~ hinge allows control D I1IIVLV& rface removal tools lost puns problems fr PATENT painting repair PENDINGcovering transportation storage etc Scale Appearance InsertSimple Assembly 3 SIZES No Slots No Pins Rotate 38-6 $445 12-6 $495 years ago Bread now $100 loaf 049 kit out world So comments Print wish Some recent correspondence has quite interesting thoughtprovokingbut cant print Dont let deter sending observations opinions Speed need inputs modelers possible can best figure out what readers may interested Keep cards letters photos coming Gene Hempel 301 N Yale Dr Gar land TX 75042 CL AerobatlcslFancher Continued page 78 applied force such manner cause yaw right air craft pitched up left pitched down thereby increasing line ten sion insides decreasing outsides examples column will consider model flying normal anti-clock wise flight battle insidious force Al devised two gimmicks First famous Rabe Rudder connected elevator apply right rudder outside maneuvers second front-Up leadout point rear Down leadout intent both cause ship yaw away pilot outside maneuvers thus neutral ize evil precession First let make clear defer no admiration accomplishments Al Rabe words Frank Sinatra did way way best ways ever once mentioned Bill Werwage handful Stunt Masters feel Al sits very comfortably same small list However. due respect Al gyroscopic precession effects real phenomenon way prop weighing under half ounce spinning modest rpms simply isnt significant trim problem three-to-four-pound mass moving 50 60 mph estimation classic example right solution wrong problem Als ships did have unique trim prob lem both devices clever solution However wasnt gyro scopic precession wit Als semiscale ships built substantial amounts dihedral Stunt Glossary Dihedral design concept wherein wing tips higher root wing Dihedral makes aircraft stable roll axis ie wing drops its ver tical lift component greater raised wing will therefore natu rally raise low wing thereby maintain ing wings-level attitude wing dihedral inherently stable posi tive-G maneuvers ie insides inherent ly unstable negative-G maneuvers ie outsides instability unpre dictable may manifest itself roll either left right What both Rabe Rudder front-Up line accomplished make inevitable roll predictable advan tageous Control Line pilot caus ing yaw accompanying roll away circle As further evidence devices best reserved bentwing birds reread Als own Mustunt arti cle American Aircraft Modeler February 1973 wherein has endless trouble making blamed rudder work basic simple straight-winged Stunter essence ends up almost no movement rudder Nuff said Well no really cause what really wanted discuss P Factor What may well asking yourself P-Factor direct answer discussion P-Factor reason should normally use rear Up line consider wig gly rudder should hook up work opposite Als ie right rudder insides Any real plane pilots addition Stunt jockeys probably nodding knowingly yourselves light dawns Please refer drawings RIDDE042 UL9LL R 1mm thick Boxed 16 oz rubber per boxSzes Price $1250 per box ppd USA32 _______1 1' TILKA ________8 WAKEFIEL $3895p.UPEnslsh3 FnshedFontEndanIdg ondFIyng 16 nst uctons Vey Connpl Send50te fo 1984/1985 catelog4 FAI Model Supply 57Torm9O51O U7i4cttijM ilk Incorporated 322 So Gallatin RdMadison TN 37115 615 868-6811 Mon thru Sat am 500 pm Ii Re p lace expensive throwaway dry cell transmitter battery recharg eable nickel cadmium battery Ready use Replaces Eveready 276 nIne volt dry cell battery Transmitter Ni-Cad Battery$3000 Transmitter Ni-Cad Charger$ 895 Battery/Charger Combo$3500 October1984 169 REPAIR SERVICE FOR HOBBY LOBBY EK LOGICTROL FUTABA T HOBBY SHACK ROYAL LINE AL RADIO SYSTEMSI FUTABA ROYAL ACCESSORIES FOR MOST RADIOSI ue BaIa 20134 STATE CERRITOS CA 90701 12131 860-1276 Regional Warehousing Sales Ollices iobout 310 N 5TH ST ST CHARLES Ii 60174 312 504-7616 Please send me ZAP/Chrissy posters $475 postpaid Enclosed check money order ________ Name Address 505 SiICIY GrOUP nierflOllOfld FRANK TIANO ENTERPRISES 628 ATE 32N NEW PALTZ NY 12561 914 6589906 StateZipI level flight both blades propel ler taking equal bites relative wind throughout entire revolution thrust therefore uniform points about prop disc see Figure 1 However whenever angle attack aircraft altered angle relative wind strikes given point aircraftincluding point prop discis changed similar fash ion see Figure 2 example lets say level flight given point prop taking 100 bite out relative wind will throughout entire 3600 propeller rotation thrust developed point prop cons tant throughout Now lets pitch up abruptly though entering Square Loop simplicitys sake lets say angle attack thus achieved also 100 sufficient gain lift needed rate turn desire Now look same given point propeller see what have done its angle tack therefore thrust delivers travels its 3600 its new relationship relative wind top bottom prop disc angle attack unchanged still 100 relative wind thus no change thrust However right ex treme descending side prop disc find prop now striking relative wind angle attack 200 thus producing much greater thrust level flight. approximately twice much greater surprise check out ever popular given point prop left extreme ascending side prop disc 100 change angle attack aircraft has total ly negated 100 bite prop blade propeller point acting flat plate producing no lift ie thrust Accepting points rotation between discussed simi larly affected linear fashion must conclude although thrust gener ated equal produced level flight center thrust therefore point thrust acts upon airframe has shifted significant distance starboard Since center drag has remained un changed net result will yaw left Solution Use aft Up line cause countering right yaw Result Right yaw cancels left yaw therefore will no yaw properly trimmed forces course reversed outside maneuvers Thus Down line can forward counteract outboard yaw Again right minus left equals zero feel P-Factor insig nificant force consider competitive Stunter has thrust-to-weight ratio ap proximately minor center thrust shift will fore have measurable impact veri fication ask real-plane pilot what does rudder pedals propdriven plane maintain heading climbing guessed right rudder last test real Doubting Thomases After practice flight CO aft because fuel has consumed changes line tension obvious series both inside outside Triangles will notice increased line tension outsides particularly top corners Also try some horizontal Hourglasses wherein line tension outside loops isnt being reduced high elevation vertical maneuver Again P-Factor will obvious last hint have Stunters hunt level flight What suppose happens leadouts far aft vain search line tension airplane yawing outward 100 tangent Oh guessed Vertical P-Factor work bottom half prop disc now producing thrust top half result plane quite logically wants climb Cute huh Ted Fancher 158 Flying Cloud Isle Foster City CA 94409 responding advertisers mention read about Model Aviation 170 Model Aviation p&~A#vP*t/ Owi&I
Edition: Model Aviation - 1984/10
Page Numbers: 78, 169, 170
Control Line Aerobatics Ted Fancher HELLO again Stunt fans swear tween trying get Rena ship finished its now June 30th have just sprayed clear over Trim-Kate United Airlines insisting actually flying paycheck beginning wonder Id ever get chance get thing writ So barring Apple turning cider goes After meet Eugene OR over last month hanging around waiting return trip noticed sharp young flier about wham comment ed last month Randy Schultz still contest site apparently practicing went out observe doing dis covered perfect subject column During competition over heard Randy Paul Walker discussing trim problem Randys ship transitioning insides outsides vice versa aircraft would yaw notice ably accompanying line-tension problems Stunt Glossary An aircraft capable movement about three axes roll pitch yaw Roll movement about lateralfore-aft axis wing tips going up down pitch movement about horizontalwing tip-to-wing tipaxis nose going up down yaw movement about vertical axis nose going right left Discussion inspection Randys ship revealed beautifully built properly balanced leadouts perhaps little far forward ballpark No readily-apparent reason problem worked leadouts however surprised discover controls set up front leadout Up line Upon inquiring learned done pur pose intended counteract gyroscopic precession Further discus sian disclosed practice nearly universal Northwest rently RELATIVE WIND ASCENDING BLADE BLACK DESCENDING BLADE WHITE TL THRUST LINE Ted wants tell us about P-Factor affects maneuvering trim Stunters quite widespread throughout country Wrong methanol breath Gyroscopic precession term ban died about Stunt circles few years back Al Rabe magnificent semi-scale Mustangs Bearcats Sea Furies threatened dominate na T /1 100 F G LEVEL FLIGHT / / 200 FIG 2 100 AofA tional competition scene According theory propounded Al mass spinning propeller acted gyro scope mounted front plane gyroscope displaced its plane rotation propagates force 900 Continued page 169 Two overseas Piotr Zawada Poland wins lot Eastern Europe original L-19 L also did well 1982 CL World Champs Swedenplaced 16th Englands Mike Weaver flies John Lynch-designed Eagle R Note hole left flap 78 Model Aviation o0I 00 Kevin Capitaneili Fairfield NJ justifiably proud plane f lies well Its Supertlgre 60 also won Best Finish award ate meet Edison NJ June 1984 Sixtyounce craft has dope finish uses solid control lines ENEAE~ hinge allows control D I1IIVLV& rface removal tools lost puns problems fr PATENT painting repair PENDINGcovering transportation storage etc Scale Appearance InsertSimple Assembly 3 SIZES No Slots No Pins Rotate 38-6 $445 12-6 $495 years ago Bread now $100 loaf 049 kit out world So comments Print wish Some recent correspondence has quite interesting thoughtprovokingbut cant print Dont let deter sending observations opinions Speed need inputs modelers possible can best figure out what readers may interested Keep cards letters photos coming Gene Hempel 301 N Yale Dr Gar land TX 75042 CL AerobatlcslFancher Continued page 78 applied force such manner cause yaw right air craft pitched up left pitched down thereby increasing line ten sion insides decreasing outsides examples column will consider model flying normal anti-clock wise flight battle insidious force Al devised two gimmicks First famous Rabe Rudder connected elevator apply right rudder outside maneuvers second front-Up leadout point rear Down leadout intent both cause ship yaw away pilot outside maneuvers thus neutral ize evil precession First let make clear defer no admiration accomplishments Al Rabe words Frank Sinatra did way way best ways ever once mentioned Bill Werwage handful Stunt Masters feel Al sits very comfortably same small list However. due respect Al gyroscopic precession effects real phenomenon way prop weighing under half ounce spinning modest rpms simply isnt significant trim problem three-to-four-pound mass moving 50 60 mph estimation classic example right solution wrong problem Als ships did have unique trim prob lem both devices clever solution However wasnt gyro scopic precession wit Als semiscale ships built substantial amounts dihedral Stunt Glossary Dihedral design concept wherein wing tips higher root wing Dihedral makes aircraft stable roll axis ie wing drops its ver tical lift component greater raised wing will therefore natu rally raise low wing thereby maintain ing wings-level attitude wing dihedral inherently stable posi tive-G maneuvers ie insides inherent ly unstable negative-G maneuvers ie outsides instability unpre dictable may manifest itself roll either left right What both Rabe Rudder front-Up line accomplished make inevitable roll predictable advan tageous Control Line pilot caus ing yaw accompanying roll away circle As further evidence devices best reserved bentwing birds reread Als own Mustunt arti cle American Aircraft Modeler February 1973 wherein has endless trouble making blamed rudder work basic simple straight-winged Stunter essence ends up almost no movement rudder Nuff said Well no really cause what really wanted discuss P Factor What may well asking yourself P-Factor direct answer discussion P-Factor reason should normally use rear Up line consider wig gly rudder should hook up work opposite Als ie right rudder insides Any real plane pilots addition Stunt jockeys probably nodding knowingly yourselves light dawns Please refer drawings RIDDE042 UL9LL R 1mm thick Boxed 16 oz rubber per boxSzes Price $1250 per box ppd USA32 _______1 1' TILKA ________8 WAKEFIEL $3895p.UPEnslsh3 FnshedFontEndanIdg ondFIyng 16 nst uctons Vey Connpl Send50te fo 1984/1985 catelog4 FAI Model Supply 57Torm9O51O U7i4cttijM ilk Incorporated 322 So Gallatin RdMadison TN 37115 615 868-6811 Mon thru Sat am 500 pm Ii Re p lace expensive throwaway dry cell transmitter battery recharg eable nickel cadmium battery Ready use Replaces Eveready 276 nIne volt dry cell battery Transmitter Ni-Cad Battery$3000 Transmitter Ni-Cad Charger$ 895 Battery/Charger Combo$3500 October1984 169 REPAIR SERVICE FOR HOBBY LOBBY EK LOGICTROL FUTABA T HOBBY SHACK ROYAL LINE AL RADIO SYSTEMSI FUTABA ROYAL ACCESSORIES FOR MOST RADIOSI ue BaIa 20134 STATE CERRITOS CA 90701 12131 860-1276 Regional Warehousing Sales Ollices iobout 310 N 5TH ST ST CHARLES Ii 60174 312 504-7616 Please send me ZAP/Chrissy posters $475 postpaid Enclosed check money order ________ Name Address 505 SiICIY GrOUP nierflOllOfld FRANK TIANO ENTERPRISES 628 ATE 32N NEW PALTZ NY 12561 914 6589906 StateZipI level flight both blades propel ler taking equal bites relative wind throughout entire revolution thrust therefore uniform points about prop disc see Figure 1 However whenever angle attack aircraft altered angle relative wind strikes given point aircraftincluding point prop discis changed similar fash ion see Figure 2 example lets say level flight given point prop taking 100 bite out relative wind will throughout entire 3600 propeller rotation thrust developed point prop cons tant throughout Now lets pitch up abruptly though entering Square Loop simplicitys sake lets say angle attack thus achieved also 100 sufficient gain lift needed rate turn desire Now look same given point propeller see what have done its angle tack therefore thrust delivers travels its 3600 its new relationship relative wind top bottom prop disc angle attack unchanged still 100 relative wind thus no change thrust However right ex treme descending side prop disc find prop now striking relative wind angle attack 200 thus producing much greater thrust level flight. approximately twice much greater surprise check out ever popular given point prop left extreme ascending side prop disc 100 change angle attack aircraft has total ly negated 100 bite prop blade propeller point acting flat plate producing no lift ie thrust Accepting points rotation between discussed simi larly affected linear fashion must conclude although thrust gener ated equal produced level flight center thrust therefore point thrust acts upon airframe has shifted significant distance starboard Since center drag has remained un changed net result will yaw left Solution Use aft Up line cause countering right yaw Result Right yaw cancels left yaw therefore will no yaw properly trimmed forces course reversed outside maneuvers Thus Down line can forward counteract outboard yaw Again right minus left equals zero feel P-Factor insig nificant force consider competitive Stunter has thrust-to-weight ratio ap proximately minor center thrust shift will fore have measurable impact veri fication ask real-plane pilot what does rudder pedals propdriven plane maintain heading climbing guessed right rudder last test real Doubting Thomases After practice flight CO aft because fuel has consumed changes line tension obvious series both inside outside Triangles will notice increased line tension outsides particularly top corners Also try some horizontal Hourglasses wherein line tension outside loops isnt being reduced high elevation vertical maneuver Again P-Factor will obvious last hint have Stunters hunt level flight What suppose happens leadouts far aft vain search line tension airplane yawing outward 100 tangent Oh guessed Vertical P-Factor work bottom half prop disc now producing thrust top half result plane quite logically wants climb Cute huh Ted Fancher 158 Flying Cloud Isle Foster City CA 94409 responding advertisers mention read about Model Aviation 170 Model Aviation p&~A#vP*t/ Owi&I