High-Lift Devices for Models

High-lift devices reduce models stall speed windy conditions Gull loiters 20 mph flaps down Weight 1s96 oz wing area 446 sq ft wing loadIng 2085 ozIsq ft power loadIng 2325 oz per cu engine displacement model takes 9 x 8 prop way sport flier achieve realism appearance performance through use flaps other high-lift devices increasing wings lifting capacity HLDs permit high wing loadings wider low-speed envelope ITS SURPRISING few Radio Control model aircraft designers have adopted high-lift devices commonplace todays crop full-scale lightplanes Flaps other high-lift devices can add new dimension RC flying Theyre simple design build make sport plane pure fun fly first two articles discusses theory application high-lift devices HLDs Part Two will explain design construction actuation primary considerations designing plain unflapped model airplane wing its area must large enough permit reasonable approach landing speeds calls wing loadings below 20 ounces per square foot wing area see Figure 1 full-flight speeds however such loading provides far wing area desirable Wing lift increases square speed mph doubled lift increases fourfold wing must fly low angles attack profile drag high solution design wing high-speed condition control low-speed envelope high-lift July 1991 101 Slotted flaps used both fore aft planes canard Swan has gross weight 115 oz takesan 08 Max 45 FSR Total wing area 464 sq ft wing loading 2475 ozIsq ft power loading 2555 oz per cu angina displacement Prop isa lOx 6 pusher DROOPED LE SN x038 SPA AlLFLAPI FLAPPED AREAS LE SLOT FLAP FUSELAfr FLAP PROPORTKJNS-STRAIGHT WING DROOPED LE FUS LAGE SPAN 2 XO38 AlL FLAPT 35% -4O 100 % SPAN CR L E SLOT FLAPPED AREAS FLAP PROPORTIONS-TAPERED WING Figure 2 Desirable flap proportions straight-wing tapered-wing designs 0 w 0 w -J 0 w w 0 00r IL 904 k LIFT CO-EFFICIENTS 8tN 80 20 70 85 60 55 040 51 /so 45 40 8 35 LO 30 EO 25 ii 4 20 H 0 HARRIER TRAINERII 4 8121620242832 36404448 WING LOADING -OUNCES PER SO FOOT LIFT-WING-LOADING PEED GRAPH Figure 1 Comparison wing loadings popular 40-size trainer flapequipped Harrier over range speeds different coefficients lift devices greatly increasing wings lifting capacity maximum coefficient lift compared simple unflapped wing such devices allow model landed maneuvered good control comparatively lower speeds What reasonable model airplane landing speeds popular 40-size trainer roughly 4 sq ft wing area weighing about 84 ounces has wing loading just under 19 ounces per square foot power loading 210 ounces per cubic inch engine displacement low Reynolds Numbers model aircraft landing speedsa wing 10-inch chord flying 25 mph operates RN195000the average wing airfoil section will generate maximum lift coefficient close 12 19 ounces per square foot wing loading C maximum 12 trainer can fly slowly 20 mph will however verge stalling higher approach speeds will necessary 102 Model Aviation Left large tlaps authors Harrier snown uiiy extenaea ne moaci weigns 104 oz uses Us Max 40 lSH wing area 4 sq ft wing loading 26 ozIsq ft power loading 260 oz per Cu engine displacement Prop lOx 6 Right Developed NASA lead ing edge droop ahead ailerons delays wing tip stall permits effective aileron control high angle attack Another model airplane incorporates high-lift devices wing Sky-Lark weighs 46 oz fitted OS Max 25 engine swinging 7 x 6 prop Wing area 208 sq ft wing loading 221 oz/sq ft power loading 3066 oz per cu engine displacement OO3 1 CL 025C QO3CT CTI contrast lift coefficient 06 trainer will fly 28 mph good control response Ideally pilot will slow aircraft raising nose just before landing touches down stall speed traditional three-point landing practice however except calm air seldom occurs Instead model flown well above stall speed combat wind gust conditions often plunked down little no reduction airspeed nose gear mains touching ground simultaneously Now consider Harrier aerodynamically clean sport model spinnered cowled engine muffler streamlined landing gear wheels no struts enclosed cockpit no wing holddown dowels wing loading 26 ounces per square foot again CL maximum 12 Harrier incorporates flaps wing flaps deployed model will stall slightly higher speed first example23 mphand lift coefficient 06 must fly 32 mph Also because its low drag model will glide flat angle engine idling Thus moderate wind conditions must brought low over flying field threshold will run out runway Harrier weighs 104 oz has wing area four square feet wing loading 26 ounces per square foot equipped large externally hinged slotted flaps spanning 60% wings trailing edge also employs leading edge droop ahead ailerons Developed NASA design feature delays wing tip stall least 100 permitting effective aileron control high angle attack Stall speed flaps down 18 mph lift coefficient 202 airplane can landed under good control moderate 25 mph drag deployed flaps permits steep approach little acceleration Takeoffs occur 25 mph flaps half deployed Without flaps model Continued page 107 THE #RED 01 #RED 02 #RED 03 #RED 04 #RED 05 #RED 14 #RED 16 #RED 23 LIGHTING SYSTEMS ORIGINALS. Still Best $2495 $1995 $3995 $1995 $1095 $2495 $1995 $2995 Programmable Flashing Navigation Lights Adjustable Rate Strobe Light Landing Lights Adjustable Rate Mars Rotating Beacon Marine Navigation Lights nonflashing Big Airplane Navigation Lights Econo Landing Lights brightest Real Strobe Light true zenon strobe 0 SEE YOUR DEALER 0 SEND STAMPED ENVELOPE FOR RAM INFO unsvilable locally send check money order full credit card info cost item plus $200 $500 foreign immediate shipment Include tull address UPS Sorry no COD Ram 4736 N Milwaukee Ave ago IL 60630 July 1991 103 authors Sea Loon teatured Ifl tfle October 1U MOaeI Aviarlon weigns 4U OZ IS pOW ered OS Max 15 swinging 7 x 4 pusher Wing area 174 sq ft wing loadIng 23 ozI sq ft power loadIng 2666 ounces per cubic Inch engine displacement Satisfaction Guaranteed cutting board Its much easier cut piece thats secured nails board thats simply lying workbench scrap piece plywood will Pound several nails through board ready use Position templates end piece foam cut Attach firmly using same kind pin used building model Position foam cutting board pushing down its snug Mold bow lay cutting wire across prongs gently slide foam Allow wire move through foam its own applying enough pressure keep moving Cutting out spar notches takes patience Dont attempt force wire through foam allow melt through seat itself Forcing wire guarantees poor results suggest start trailing edge work forward thats comfortable however theres nothing wrong doing other way around Cut out top bottom wing turn foam over cut out other side Set wing aside together scrap cut cases youll need cut second foam blank other wing half Set up templates another piece foam repeat entire process Give foam light sanding finishing replacement wing ready Foam-cutting easy way well worth learning can use technique cutting other model parts too wish thank fellow Californians Paul Ross Lakeside Doug Wilsman Ramona making number helpful suggesttons Please contact questions need information offered Ill glad provide ask enclose SASE Write 310 N Hunter St Ramona CA 92065 D High-Lift/Lennon Continued page 103 would have accelerate around 35 mph would have lower rate climb flaps rugged may lowered partially fully point models flight Turning maneuvers loops very tight flaps down Harrier has flown repeatedly windy conditions flaps down nose up engine throttled back model hovers little ground speed yet remains under good control Fellow fliers surprised doesnt stall fall off spin powered OS Max 40 FSR engine turning 10 x 6 propeller best ways keep cool S maintain control ROBART HINGE POINTS Simply best hinging system available application Drill hole add drop glue Hinge Point youre hinged DON TBEA ROBART CONTROL HORNS accurate on-center control linkage No need bent kinked control lines use horns built-in rotating ball link Reach other fine ROBART products hobby deaters nattonwide ROBART MFG POBOX 1247 STCHARLES IL 60174 708-584-7616 July 1991 107 TSIG1 SH71O Pkg 0124 $295 EA~ HINE_ THE HIGH-TECH HINGE DESIGNED FOR THE CYANOACRYLATE AGE Easier install other hinge No gouging picking messy epoxies Simply cut single knife slot hinge slide hinges place apply few drops favorite CA glue youre done SUPER FAST SUPER EASY SUPER STRONG SIG MFG CO INC.401-7 So Front St.Montezuma IA 50171 23-5154 ROBART HINGE POINTS AND CONTROL HORNS. K -L Cemplef reedy fluiD lessmwffleajw buffeay & prepell -v I [I I I iI1 New Generation -20 Cubic Inch A&M Aircraft Sachs Dolmar Smaller Better says bigger better applications easily interchange 20 Cubic Inch engine trom A&M Aircratt tor size power get phenomenal 5x5x5 31/s lbs little guy puts Out 4 Cu 8000 horsepower tor mere $300 Gas $275 Glow Call tax today order Suggested Propeller Sizes 18x8 18x6-10 18x1018x8x14 20x6-10 plane takes off climbs ably 40-powered ships lesser weight also has wider speed range capable aerobatics book Under strong wind conditions however its best use little no flap Because higher wing loading exerts beneficial effect airspeed increases penetration control improved Bear mind landing wind slows model reducing its ground speed steepening approach pilots have reservations about flying models equipped flaps reason flaps lowered model pitches sharply upward low speed friend fellow club member Dick Murray cleverly avoids applying elevator down trim neutralize upward pitch lowers flaps Harrier continues level flight becomes noticeably slower High-lift devices permit high wing loadings moderate maneuvering landing speeds devices buy A&M Aircraft youre buying best P Cs saies lax appicaoie Free freighi pre pa orders check money order A&MAuAFr INC 1428 McArthur Suite 102 Carrolllon TX 75007 214/242-4684 Fax 214/242-1378 together servos linkages will add about six seven ounces models weight thats far bridging 20-oz differential between 80-oz trainer 104-oz Harrier Beneficial weight may added use larger spinners enclosed ducted engine muffler cowlings rounded fuselages landing gear strut fairings wheel pants fully balsa sheeted stress-skinned rugged structures higher capacity receiver batteries larger fuel tanks Models equipped HLDs versatile rugged much fun fly Theyre well worth extra work cost materials transmitter servos etc involved making larger quarter-scale models normally fly faster would also benefit HLDs Figure 2 shows desirable flap proportions both straight tapered wings Part Two will discuss design responding advertisers mention read about Model Aviation construction actuation high-lift devices Vintage Stunt/Keville Continued page 88 reworked OS 40 FP SuperTigre 46 Tom Lay T&L Specialties bought $100 worth tickets Dougs competitor tank business Kenn Smith donated half considerable sales weekend cause Yes family Thats like get together least once year andfor bragging rights mostlytry beat others brains out flying circle way raffle winner New Mexicos Gary Marchand chose SuperTigre 46 Hows quality judging meets Try Bill Zimmer District VI AVP Jim Renkar Illinois Lew Woolard Kansas Gene Mills Indiana judged Old-Time Stunt 90 Nats plus Fred Brigeman Gary Akers Kenn Smith southern California ever-present De Hill Oklahoma last-minute recruiting effort OT-Ignition judges yielded Bob Hunt Doug Taffinder Thats serious judging folks weekend wouldnt have possible first-rate registration Snuf-Vibe BACK PLATE MOUNTS Front Intake Engines Aluminum Back Plate Mounts Sr light weight easy install Just bolt engine crank case mounts see equipped SNUF-VIBE isolation system double protection engine vibrelion SIX SIZES FOR ENGINES 15 TO 182 JT-BPi 09- 15 1496 JT-BP2 19- 28 1495 JT-BP3 29- 056 1496 sot available hobby shop ORDER DlttClforimmedialtshipwent Check MO Visa MC COD accepled Add $250 UPS 6306 COD sod 6% ooleo lax Calif resideots JT-BP4 60 901496 JT-BPS MAX 90-106 1796 JT-BP6 ST2500-3000 2196 U 9z IWN mm SEND 25o STAMP FOR AIIDITINAI INFO— AND JIEC CATAIRO 164 School St. Daly CIty CA 84014 141617663400 GIANT SCALE FLYIN SHOW-In air action close ups VOLUME IrA Scale entertainment helpful hints VOLUME 2-Mid Atlantic Ducted Fan Jet Show tape $1995 shipping & handling Virginia residents add 90r sales fax Send money order check Sr COD AIRPLANE VIDEO CO PO Box 8577 Norfolk VA 23503 400-1553 Send SASE compiere Lsrrrrg Oroduars ro Aerospace Composite Prodilcts PO Box 16621 Irvine CA 92714 t714250-1107

High-lift devices reduce models stall speed windy conditions Gull loiters 20 mph flaps down Weight 1s96 oz wing area 446 sq ft wing loadIng 2085 ozIsq ft power loadIng 2325 oz per cu engine displacement model takes 9 x 8 prop way sport flier achieve realism appearance performance through use flaps other high-lift devices increasing wings lifting capacity HLDs permit high wing loadings wider low-speed envelope ITS SURPRISING few Radio Control model aircraft designers have adopted high-lift devices commonplace todays crop full-scale lightplanes Flaps other high-lift devices can add new dimension RC flying Theyre simple design build make sport plane pure fun fly first two articles discusses theory application high-lift devices HLDs Part Two will explain design construction actuation primary considerations designing plain unflapped model airplane wing its area must large enough permit reasonable approach landing speeds calls wing loadings below 20 ounces per square foot wing area see Figure 1 full-flight speeds however such loading provides far wing area desirable Wing lift increases square speed mph doubled lift increases fourfold wing must fly low angles attack profile drag high solution design wing high-speed condition control low-speed envelope high-lift July 1991 101 Slotted flaps used both fore aft planes canard Swan has gross weight 115 oz takesan 08 Max 45 FSR Total wing area 464 sq ft wing loading 2475 ozIsq ft power loading 2555 oz per cu angina displacement Prop isa lOx 6 pusher DROOPED LE SN x038 SPA AlLFLAPI FLAPPED AREAS LE SLOT FLAP FUSELAfr FLAP PROPORTKJNS-STRAIGHT WING DROOPED LE FUS LAGE SPAN 2 XO38 AlL FLAPT 35% -4O 100 % SPAN CR L E SLOT FLAPPED AREAS FLAP PROPORTIONS-TAPERED WING Figure 2 Desirable flap proportions straight-wing tapered-wing designs 0 w 0 w -J 0 w w 0 00r IL 904 k LIFT CO-EFFICIENTS 8tN 80 20 70 85 60 55 040 51 /so 45 40 8 35 LO 30 EO 25 ii 4 20 H 0 HARRIER TRAINERII 4 8121620242832 36404448 WING LOADING -OUNCES PER SO FOOT LIFT-WING-LOADING PEED GRAPH Figure 1 Comparison wing loadings popular 40-size trainer flapequipped Harrier over range speeds different coefficients lift devices greatly increasing wings lifting capacity maximum coefficient lift compared simple unflapped wing such devices allow model landed maneuvered good control comparatively lower speeds What reasonable model airplane landing speeds popular 40-size trainer roughly 4 sq ft wing area weighing about 84 ounces has wing loading just under 19 ounces per square foot power loading 210 ounces per cubic inch engine displacement low Reynolds Numbers model aircraft landing speedsa wing 10-inch chord flying 25 mph operates RN195000the average wing airfoil section will generate maximum lift coefficient close 12 19 ounces per square foot wing loading C maximum 12 trainer can fly slowly 20 mph will however verge stalling higher approach speeds will necessary 102 Model Aviation Left large tlaps authors Harrier snown uiiy extenaea ne moaci weigns 104 oz uses Us Max 40 lSH wing area 4 sq ft wing loading 26 ozIsq ft power loading 260 oz per Cu engine displacement Prop lOx 6 Right Developed NASA lead ing edge droop ahead ailerons delays wing tip stall permits effective aileron control high angle attack Another model airplane incorporates high-lift devices wing Sky-Lark weighs 46 oz fitted OS Max 25 engine swinging 7 x 6 prop Wing area 208 sq ft wing loading 221 oz/sq ft power loading 3066 oz per cu engine displacement OO3 1 CL 025C QO3CT CTI contrast lift coefficient 06 trainer will fly 28 mph good control response Ideally pilot will slow aircraft raising nose just before landing touches down stall speed traditional three-point landing practice however except calm air seldom occurs Instead model flown well above stall speed combat wind gust conditions often plunked down little no reduction airspeed nose gear mains touching ground simultaneously Now consider Harrier aerodynamically clean sport model spinnered cowled engine muffler streamlined landing gear wheels no struts enclosed cockpit no wing holddown dowels wing loading 26 ounces per square foot again CL maximum 12 Harrier incorporates flaps wing flaps deployed model will stall slightly higher speed first example23 mphand lift coefficient 06 must fly 32 mph Also because its low drag model will glide flat angle engine idling Thus moderate wind conditions must brought low over flying field threshold will run out runway Harrier weighs 104 oz has wing area four square feet wing loading 26 ounces per square foot equipped large externally hinged slotted flaps spanning 60% wings trailing edge also employs leading edge droop ahead ailerons Developed NASA design feature delays wing tip stall least 100 permitting effective aileron control high angle attack Stall speed flaps down 18 mph lift coefficient 202 airplane can landed under good control moderate 25 mph drag deployed flaps permits steep approach little acceleration Takeoffs occur 25 mph flaps half deployed Without flaps model Continued page 107 THE #RED 01 #RED 02 #RED 03 #RED 04 #RED 05 #RED 14 #RED 16 #RED 23 LIGHTING SYSTEMS ORIGINALS. Still Best $2495 $1995 $3995 $1995 $1095 $2495 $1995 $2995 Programmable Flashing Navigation Lights Adjustable Rate Strobe Light Landing Lights Adjustable Rate Mars Rotating Beacon Marine Navigation Lights nonflashing Big Airplane Navigation Lights Econo Landing Lights brightest Real Strobe Light true zenon strobe 0 SEE YOUR DEALER 0 SEND STAMPED ENVELOPE FOR RAM INFO unsvilable locally send check money order full credit card info cost item plus $200 $500 foreign immediate shipment Include tull address UPS Sorry no COD Ram 4736 N Milwaukee Ave ago IL 60630 July 1991 103 authors Sea Loon teatured Ifl tfle October 1U MOaeI Aviarlon weigns 4U OZ IS pOW ered OS Max 15 swinging 7 x 4 pusher Wing area 174 sq ft wing loadIng 23 ozI sq ft power loadIng 2666 ounces per cubic Inch engine displacement Satisfaction Guaranteed cutting board Its much easier cut piece thats secured nails board thats simply lying workbench scrap piece plywood will Pound several nails through board ready use Position templates end piece foam cut Attach firmly using same kind pin used building model Position foam cutting board pushing down its snug Mold bow lay cutting wire across prongs gently slide foam Allow wire move through foam its own applying enough pressure keep moving Cutting out spar notches takes patience Dont attempt force wire through foam allow melt through seat itself Forcing wire guarantees poor results suggest start trailing edge work forward thats comfortable however theres nothing wrong doing other way around Cut out top bottom wing turn foam over cut out other side Set wing aside together scrap cut cases youll need cut second foam blank other wing half Set up templates another piece foam repeat entire process Give foam light sanding finishing replacement wing ready Foam-cutting easy way well worth learning can use technique cutting other model parts too wish thank fellow Californians Paul Ross Lakeside Doug Wilsman Ramona making number helpful suggesttons Please contact questions need information offered Ill glad provide ask enclose SASE Write 310 N Hunter St Ramona CA 92065 D High-Lift/Lennon Continued page 103 would have accelerate around 35 mph would have lower rate climb flaps rugged may lowered partially fully point models flight Turning maneuvers loops very tight flaps down Harrier has flown repeatedly windy conditions flaps down nose up engine throttled back model hovers little ground speed yet remains under good control Fellow fliers surprised doesnt stall fall off spin powered OS Max 40 FSR engine turning 10 x 6 propeller best ways keep cool S maintain control ROBART HINGE POINTS Simply best hinging system available application Drill hole add drop glue Hinge Point youre hinged DON TBEA ROBART CONTROL HORNS accurate on-center control linkage No need bent kinked control lines use horns built-in rotating ball link Reach other fine ROBART products hobby deaters nattonwide ROBART MFG POBOX 1247 STCHARLES IL 60174 708-584-7616 July 1991 107 TSIG1 SH71O Pkg 0124 $295 EA~ HINE_ THE HIGH-TECH HINGE DESIGNED FOR THE CYANOACRYLATE AGE Easier install other hinge No gouging picking messy epoxies Simply cut single knife slot hinge slide hinges place apply few drops favorite CA glue youre done SUPER FAST SUPER EASY SUPER STRONG SIG MFG CO INC.401-7 So Front St.Montezuma IA 50171 23-5154 ROBART HINGE POINTS AND CONTROL HORNS. K -L Cemplef reedy fluiD lessmwffleajw buffeay & prepell -v I [I I I iI1 New Generation -20 Cubic Inch A&M Aircraft Sachs Dolmar Smaller Better says bigger better applications easily interchange 20 Cubic Inch engine trom A&M Aircratt tor size power get phenomenal 5x5x5 31/s lbs little guy puts Out 4 Cu 8000 horsepower tor mere $300 Gas $275 Glow Call tax today order Suggested Propeller Sizes 18x8 18x6-10 18x1018x8x14 20x6-10 plane takes off climbs ably 40-powered ships lesser weight also has wider speed range capable aerobatics book Under strong wind conditions however its best use little no flap Because higher wing loading exerts beneficial effect airspeed increases penetration control improved Bear mind landing wind slows model reducing its ground speed steepening approach pilots have reservations about flying models equipped flaps reason flaps lowered model pitches sharply upward low speed friend fellow club member Dick Murray cleverly avoids applying elevator down trim neutralize upward pitch lowers flaps Harrier continues level flight becomes noticeably slower High-lift devices permit high wing loadings moderate maneuvering landing speeds devices buy A&M Aircraft youre buying best P Cs saies lax appicaoie Free freighi pre pa orders check money order A&MAuAFr INC 1428 McArthur Suite 102 Carrolllon TX 75007 214/242-4684 Fax 214/242-1378 together servos linkages will add about six seven ounces models weight thats far bridging 20-oz differential between 80-oz trainer 104-oz Harrier Beneficial weight may added use larger spinners enclosed ducted engine muffler cowlings rounded fuselages landing gear strut fairings wheel pants fully balsa sheeted stress-skinned rugged structures higher capacity receiver batteries larger fuel tanks Models equipped HLDs versatile rugged much fun fly Theyre well worth extra work cost materials transmitter servos etc involved making larger quarter-scale models normally fly faster would also benefit HLDs Figure 2 shows desirable flap proportions both straight tapered wings Part Two will discuss design responding advertisers mention read about Model Aviation construction actuation high-lift devices Vintage Stunt/Keville Continued page 88 reworked OS 40 FP SuperTigre 46 Tom Lay T&L Specialties bought $100 worth tickets Dougs competitor tank business Kenn Smith donated half considerable sales weekend cause Yes family Thats like get together least once year andfor bragging rights mostlytry beat others brains out flying circle way raffle winner New Mexicos Gary Marchand chose SuperTigre 46 Hows quality judging meets Try Bill Zimmer District VI AVP Jim Renkar Illinois Lew Woolard Kansas Gene Mills Indiana judged Old-Time Stunt 90 Nats plus Fred Brigeman Gary Akers Kenn Smith southern California ever-present De Hill Oklahoma last-minute recruiting effort OT-Ignition judges yielded Bob Hunt Doug Taffinder Thats serious judging folks weekend wouldnt have possible first-rate registration Snuf-Vibe BACK PLATE MOUNTS Front Intake Engines Aluminum Back Plate Mounts Sr light weight easy install Just bolt engine crank case mounts see equipped SNUF-VIBE isolation system double protection engine vibrelion SIX SIZES FOR ENGINES 15 TO 182 JT-BPi 09- 15 1496 JT-BP2 19- 28 1495 JT-BP3 29- 056 1496 sot available hobby shop ORDER DlttClforimmedialtshipwent Check MO Visa MC COD accepled Add $250 UPS 6306 COD sod 6% ooleo lax Calif resideots JT-BP4 60 901496 JT-BPS MAX 90-106 1796 JT-BP6 ST2500-3000 2196 U 9z IWN mm SEND 25o STAMP FOR AIIDITINAI INFO— AND JIEC CATAIRO 164 School St. Daly CIty CA 84014 141617663400 GIANT SCALE FLYIN SHOW-In air action close ups VOLUME IrA Scale entertainment helpful hints VOLUME 2-Mid Atlantic Ducted Fan Jet Show tape $1995 shipping & handling Virginia residents add 90r sales fax Send money order check Sr COD AIRPLANE VIDEO CO PO Box 8577 Norfolk VA 23503 400-1553 Send SASE compiere Lsrrrrg Oroduars ro Aerospace Composite Prodilcts PO Box 16621 Irvine CA 92714 t714250-1107