Radio Control: Aerobatics

RADIO CONTROL AEROBATICS U fl ~ WE HAVE BEEN considering some fundamental aspects viscous black art aerobatic flight discussion month has pitch stability balancing airplanes possible fly RC models knowing diddly-do about aerodynamics Kids operate dime-store gliders time knowing squat about lift drag thrust fluid mechanics just buy fly figure out wing speak Nowadays lots brand-new adult modelers same thing ARFs have become entry-level trainer machines choice Im bashing ARFs contrary Im grateful have allowed people enter hobby during time-challenged workaholic decade 90s same indisputable essence ARF phenomenon instant gratification new friends prefer get straight fun flying learning much about what trying Like kid dime-store glider theyd rather figure out wing dime-store gliders RC models have few common characteristics wing tailplane little balsa etc price isnt comes RC flopping around cocoon impenetrable ignorance empirically gathering basic data has already collected sorted collated published huge stacks sillyits downright expensive Asking questions reading books magazines like far cheaper crashing models before can get anything basic out column have put can get away putting because case knowledge mechanics pitch stability important beginning Pattern acrobat beginning RCer hear term Center Gravity CC lot Actually term Balance Point BP accurate since purposes merely looking spot somewhere wing fore-andaft balance model Center Gravity actual center mass entire aircraft may located well above below wing may seem fine point matters some aerobatic maneuversmost especially rolls doesnt matter much current topic pitch stability isnt intention get huge involved technical discussion understanding few common terms might helpful Aerodynamic Center AC point action sum aerodynamic forces acting aircraft flight practical purposes fixed point does change airspeed position model air also sometimes referred Neutral Point AC individual airfoils falls very close 25% MAC Mean Aerodynamic Chord Finding point entire aircraft complicated business involves calculating individual ACs wing stab fin fuselage wheel pants etc adding vector addition since streamlined components stick out slipstream function wings some fashion purpose going say conventional aircraft AC almost always falls main wing between about 35-50% Mean Aerodynamic Chord Mean Aerodynamic Chord MAC just average chord width wing various ways find Its pretty simple wing constant-chord same width root tip simple tapered wings decent quick-and-dirty method just add root tip chords together divide two Move ruler around wing plan parallel wing centerline until find particular width mark called find percentage MAC calculate favorite units calculator February 1999 67 Chris Lakin starts Sukhoi 97 TOC rules allow 10% design deviation scale Chris obviously opted increasing tail moment arm Scratch-built original design Masters competitor Gary Fowler Auburn Washington Radio JR YS power model good performer abacus fingers-and-toes measure leading edge back Project line perpendicular chord line point centerline wing Bingo Yes know can add tip root root tip draw nice crisscross lines Im just lazy dont much feel like drawing diagram Pitch Stability stability lack same longitudinal fore-and-aft axis aircraft An aircraft has positive stability tends always settle down oscillation return line flight commanded position flight controls after being disturbed Think balancing ball bottom round bowl Neutral stability airplane has no tendency damp oscillations after being disturbed Think balancing ball sheet glass Negative stability tendency oscillations increase divergence Think balancing ball bottom inverted round bowl well-behaved aircraft size shape needs least some degree positive stability An aircraft may perfectly stable pitch unstable radioactive isotope roll yaw axis another story another time Moment Arm simple lever through force considered act aircraft Tail Moment Arm would distance AC wing AC stab Nose Moment Arm distance prop hub wing AC conventional layout practice people measure tail moment BP elevator hingeline about accurate usual government survey probably close enough horseshoes moment arms Stability comes degrees Some airplanes need stability others Trainers usually designed excess stability sport aircraft somewhat less aerobatic airplanes less Fun Fly-type aircraft typically have least stability time lay down some rules thumb aircraft stable pitch Balance Point must located front AC Neutral Point distance between two referred Static Margin bigger stab longer tail moment arm farther back AC will farther back BP can As static margin increased stability increases As stability increases control authority decreases entirely possible have too much stability situation becomes worse decaying airspeed Continued page 72 68 Model Aviation Dunphy longtime Pattern competitor official proprietor Precision Aero Composites strikes pose 98 Nats Real Shock Absorbing Action Straight Offset ONLY ROBART ROBOSTRUTS CARRY THE TST AIRCRAFT PERFORMANCE CERTI Best Replacement Wire Gear Big Performance Increase Sizes Right Any Model Easy Install Minutes Aircraft Grade Materials Robart Reliability direct replacement standard wire tear RoboStruta breeze install JIb increase performance bigcimel RoboStruts can also attached Robart other pneumatic retracts Strut Riaht Stuff Boho8tut625Robart Manufacturing Inc 5/8 Diam 1 8-50 lb ModelsPOBox 247 Dept StCharles IL 601 74 Phone 630-5847616 E-mail robart@robartcom right stuffon web @ httpllwwwrobortcorn Industry Leader Retractable Landing Ceor Fixed Scale Struts Control Horns 1-lingePoint Hinges Modeling Tools Morel Now 4 Sizes RoboStruts t real aircraft performance model live flohoStut38Gfunctioning oleo strut suspension Robart RoboStruts Smooth stick-to Boho$tut44Ocontrolled landings no bounce manufactured aircraft grade chrome floho$tut5GOmoly steel lightweight units attest proven Robart reliability performance YELLOW AIRCRAFT INTERNATIONAL Excellence Englnevlng Quality Manufacturing 203 Mass Ave Lexington MA 021734003 USA TEL 781674-9898 FAX 781674-2288 RC Aerobatics/Allison Continued page 68 enduring tenet RC nose-heavy models safe solid predictable iron-clad rule myth dont know times Ive seen models stall landing approach fall out sky simply because too nose-heavy works like maintain altitude forward flight wing must held positive-enough angle attack create lift thing doing holding horizontal stabilizer via elevator control nose-heavy model tail down-load up elevator takes keep wing biting air some point model slows airspeed over elevator decays control loses its ability keep wing proper angle attack elevator stall wing does what good positively cambered rigged wings want pitch down dumps lift Model impacts ground thud comedy errors often gets funnier wounded modeler immediately claims airplane balanced too far aft because nose-heavy airplanes dont stall actually adds weight nose Too-nose-heavy just bad tootail-heavy either will bend balsa Believe nose-heavy airplane will stall faster airspeed given same angle attack tail-heavy difference tailheavy airplane will stall nastily snap crunch nose-heavy airplane pitch down thud So far Pattern aerobatics goes think pilots would agree ideal Pattern airplane would almost neutral stability like able place aircraft precisely flight attitude have stay further input until command different flight attitude course some minimum amount positive stability must designed provide Email kingindustries@earthlinknet http//homeearthlinknet/4ingindustries/indexhtm SpinMaster aluminum spinner cones prop nuts available through manufacturer product precision made quality light weight performance made USA money back guarantee competitive prices cant go wrong owning SpinMaster product information place order visit web page phone fax toll free 1888-299-9476 FREE SHIPPING AND HANDLING USA Prop Nuts $599 ea Spinner Cones 3 -$2499 ea 25 in-$1699ea 225 -$1499 ea 72 Model Aviation 104~3da25dia25dia#2225dia AdapterKit Mfg King Industries 2924 E Eaton Dr Terre Haute IN 47802 $49500 DELUXE KIT FEATURES Fiberglass Fuselage Integral Vertical Fm Interform Recess-Molded Fiberglass Access Hatch Fiberglass Inlet Ducts Ready Install Fiberglass Exhaust Ducts Formers Bulkheads Precut Sanded Ready Install Balsa Presheeted Foam Core Wings Horizontal Stabs LE Installed Flaps Standard Feature Landing Gear Blocks Installed Wings Optional Plug Wings Vacuum Formed Clear Canopy Fiberglass Canopy Frame Also Available F/A18 Twin & Single F16 F4E A4 P38 P47 Spitfire ZERO AT-6 CAP-lOB Send $4 within USA $10 rest world PRODUCT INFO PACK damping prevent divergence dynamic instability designer trick get certain minimum amount no Too much positive stability aerobatic aircraft leads very high pilot workload nearly constant control input called just keep model trying return its primary trimmed condition otherwise known straight-and-level flight dont believe suggest spend some time trying fly 8-point roll trainer Generally speaking advantage have CU pretty far rear Pattern airplane dont stick back pretty far snap rolls spins arent possible let alone pretty important dont want have counteract overall nosedown pitching moment caused forward CU carrying up trim rerigging stab negative incidence wing positive want mainplane tailplane rigged nearly same angle thing airplane rolls inverted up trim becomes down trim Large angle-of-attack changes elevator deflections required hold airplane lineand case consecutive rolls better quick changes Knife-edge flight another case wing tail supposedly unloaded aerobatic designs too much difference between rigging angles wing tail excessive up elevator trim will show lateral pitch canopy same thing true vertical lines both up down might primary reason move CC around achieve level flight trim condition involves minimum difference incidence trim between mainplane tailplaneit simplifies minimizes other trim adjustments might need make such thrustline changes radio mixing primary flight controls purposes would like fairly aft CG main tailplanes rigged nearly identical angles plus dont want carry much trim level flight want airplane trim out hands-off stable horizon horizon Nice problem Unfortunately moving CU rear closer NP makes airplane skittish Pitch loads too light damping action decreased model easily disturbed gusts tends hunt rather groove Pitch stability has decreased regain lost static margin thus pitch stability have two main ways go can move CU forward can increase tail volume modern Pattern aircraft design solution over past decade has increase tail volume Tail volume moment arm times area increase either makes increase whole An increase both what see lot days accomplishes couple important things First increases tailplane efficiency longer lever arm increased area allow stabilizer effective both control damping Second increase tail volume moves Neutral Point aircraft rear Moving NP rear increasing tail volume regains static margin missing pitch stability BP can stay aft enough provide lively control response good spin/spin entries aircraft remains positively stable level flight damps well both knife-edges verticals behave themselves Hundreds thousands innocent trees have died providing raw material trimming charts articles published through sgd%PoT issue build 0 decidedly different tail feathers DAWs Foam P-51 D combat 2-hrs long slope soarer also eyeball Futaba s PA-I Pilot Assist Link device helping stabilize model lets master R/C flight & solo quickly Awesome hotSHOTS features X-1 rocketdropping B-29 brief visit Jet World Masters Swindon England awesome ducted fan Antonov ROT8 begin build ing robbes Millennium 60 helicopter aboutENGINES run Thunder Tigers honking 46H PRO ABC look YSs super trick 53 thumper Learn secrets using airbrush create professional look ing weathered effect FW1 90 Next add nay landing lights DC-3 cover story add flaps Hanger 9s hot new ARE Cessna 182 Skylane ask local hobby dealer Sheldons Hobbies 8001822-1688 National Hobby Supply 800/437-2736 Hobby Barn8001324-4910 Tammies Hobbies800/521-5614 HobbyTown USAwwwhobbytowncom Phone 507 268-4084 FAX 507 268-3245 Its international call must first dial 011 www modelsport com February 1999 75 HANDS ON PRO-BOW THIS UNWUEDEVICEALLOWS YOU TO CUT ACCU RATE WING CORES WITHOUT EXPENSIVE AND COMPLICATED EQUIPMENT WITH THE PRO-BOW THE CUTTING WIRE IS GUIDED DIRECTLY AT THE TEMPLATES BY HAND HELD INSULATOR CLIPS THE HEAVY-DUTY CONSTRUCTION GIVES GOOD FEEL TO THE BOW AND WITH THE ADJUSTABLE HEAT PROBE THE WIRE TEMPERATURE CAN BE CONTROLLED FOR PERFECT CUTTING RESULTS sale $4999 WORKS DIRECTLY OFF OF 12 VOLT BATTERY OR 10 AMP BATTERY CHARGER S COMPLETELY ASSEMBLED STRAIGHT DR TAPERED CORES IAL PASSIVE RESISTANCE CUTTING WIRE LATED STEEL FRAME CUTTING TECHNIQUES & OPERATING INSTRUCTIONS INCLUDED UP TO 41 SEND $500 FOR 60 PAGE CATALOG VISA ERCARD ACCEP TEDADD $500 SHIPPING IN USAIL RESIDENTS ADD 725% TAX WING MFG306 E SIMMONSGALESBURG IL 61401 visit us http//wwwwingmfgcomCALL 309-342-3009 years worth noting cookbooks BP location CG first last main item checked rechecked changed manipulated because affects aircraft flight modes bears other trim adjustment might make Nothing important Unfortunately some kits come appropriate location plainly marked some just show range others show nothing Some models acquired already built sans plans Much has written about fine-tuning BP during flight testing get close enough safely fine-tune Try recipe works allows try out understanding terms defined above Measure tail moment arm mean aerodynamic chord calculate areas both wing stab Assuming stab average size 20-25% wing area divide moment arm MAC number get 275 larger set BP 33-35% MAC number 25 275 set 28-32% Smaller 25 set BP 25-28% MAC stab smaller average shade numbers low side range BP further forward stab larger average reverse true good initial placement BP 99% time will get close wont need move again method good Pattern models symmetrical airfoils also works almost common flat-bottom semisymmetrical airfoils see RC So go ahead figure out wing like just before fly may take few hours time thats cheap compared new models antidepressants psychotherapy 1 0 40 Size ARF wood construction wieg tail tips covered Oracover Germany tasy assemble easy repair Flat bottom air toil Sayer otable characteriotics make perfect tsr new pilots Feel tank wheels landing gear spinner hardware etc incladed Radio esquires 4 C5 wins Span 04 Wins Area 720 sq Piping WI 00 05 ne 40 40 3d1 Combo JL-316 wfilrunder Tiger GP-42 Eagine$13999 IVn Super Cemba add HiTec Focus 4 ch FM Radio$26499 Thunder Tiger 4060 size Tgo T ane tombas pease call far price descniptien High quality lowest price Americal F4U Corsair 40 Size ARFP 51 Mustang 40 Size ARF intheUSA 0 $i89~ Radro nequres 4 h 0 servos span asRadio nequires 5 cs 5 servosl wins span 07eadin nequires 4 cs winn span 040 Wing Wing Area 035 sq ns Wi 03 lbs wino Area 005 sq ng wt 0 ibsArea 520 in. Fiping Wt 52 ibs ungine 40unsine 40 uin l2c sr 4a gine 40- 03 cuin l2c 53 75 14C 3 con 2c 40-70 dc Optien piece Option Painted piece P/g cowi $2109instailed retractsPlO dovi $1999 Combo Pro46 tagine$26699Combo Prs46 Engine$26899Combo Pro46 Engine$25699 w/F-54S 40 Engine 99w/F-545 40 Engine 99w/F-54S 40 Engine 99 Twin Sukhoi Sport ARFUltimate 30 Size ARFCap 231 40 Size AFIF Made USA nadin Onquirns 4 co Span 070 Wing Radio nequires 4 co Wing Span 4t 7 Radio Requires 4 co 10 servos Wing Span 50 Area 070 sq ng Wt 90 ibs ungine IwoArea 570 sq Fiving wt 44 iSo ne 35-in Wing Area 550 sq Piping Wt 59 iSo 40 -53 coin 201 tao 40 054040 coin 2cl 53 4CEngine 40 53 ruin 3d 00-90 4c Combo with 2 Prs46 Engineo $48399 Combo Pro46 Engine 699 Combo Pro46 Engine - $26699 w/2 F-545 4C tngneo$62799wlF-545 40 Engine $29999w/F-915 40 Engine $37999 Super Chipmuok 60 Size ARFUltimate 120 AFIF $2A9 Radio Requires 0 cs 7 servos Span 04 in wing Area sq ng wt 00 iSo Engine 001201 St 4c Prn-instaiied retracts $389 ard tiaps Radio Requires 4 h 5 servos Span onRadio Requires 4 cs 5 servos wing Span 5$ in Area 075 sq ng Wt 92 Combo ProOl tngine 699 Wing Area 1013 no Wt 05 iSo Engine 90- t go coin Oc t 20 40wIF-Ol $ 40 Engine 99Engine tOO tOO coin 40 Engine Special Thunder Tiger Aircraft Engine / GP-15 . $4595Pro-4ii 99 GP-25$4999Pro-46 99 GP-42$5499Pro-fl 999Au Oils Pre-covered reai heat-shrink GP-61 99Pro-120 99poipester tiiv Onaconer tiny Sermany $500 500 Pro-25 9F54S 14C1 $16899Oversite bones higher 000 cash Snip Add gOOg Pro 36 9F-91S 14C $20999 1/6 Scale Cub ARF $120 Radio Requires 400 5 servos Wing Spar 71 wing Area 008 sq in. Piping WI 32 iSa ne 40-53 cv 40 Combs wIF-OlS 40 Engine 1/4 Scale Cub AFIF $429Y Radio Requires 4 0h5 servos Span 104 in Wing Area 1012 sq ir Piping WI 149 iSo Engine 120-150 cv 40 RIC SERVICE AT ITS BEST Sales Service Anything Radio Controlled KMI 7420 Seven Mile Rd Northville Michigan 48167 Ph 248-486-4800 Fax 248-486-1603 Winner RIC HobbiesORDERS ONLY 800780-0100 15437 Proctor Aye Hacienda Hts CA 91745lotormation 626-961-4616 626-330-9351 wwwWinnerRCcom Repairs Updates Custom Modifications Frequency Changes 6 Send Legal sized SAE 1997 Meter conversions ACE Airtronics Aristo-craft Cirrus EK Catalog containing lists RIC maintenance hints Futaba Hitec Heathkit Hobby Shack JR Kraft KGL KSE Kline Discover MCard VISA COD KoPropo Pro-Line RCD Tower Hobbies World Engines & others UPS USMAIL FEDEX etc Calibrated Equipment Quick Turnaround Walk-in daily service 800 am-500 pm Send E-Mail PTWaters@junocom February 1999 77

RADIO CONTROL AEROBATICS U fl ~ WE HAVE BEEN considering some fundamental aspects viscous black art aerobatic flight discussion month has pitch stability balancing airplanes possible fly RC models knowing diddly-do about aerodynamics Kids operate dime-store gliders time knowing squat about lift drag thrust fluid mechanics just buy fly figure out wing speak Nowadays lots brand-new adult modelers same thing ARFs have become entry-level trainer machines choice Im bashing ARFs contrary Im grateful have allowed people enter hobby during time-challenged workaholic decade 90s same indisputable essence ARF phenomenon instant gratification new friends prefer get straight fun flying learning much about what trying Like kid dime-store glider theyd rather figure out wing dime-store gliders RC models have few common characteristics wing tailplane little balsa etc price isnt comes RC flopping around cocoon impenetrable ignorance empirically gathering basic data has already collected sorted collated published huge stacks sillyits downright expensive Asking questions reading books magazines like far cheaper crashing models before can get anything basic out column have put can get away putting because case knowledge mechanics pitch stability important beginning Pattern acrobat beginning RCer hear term Center Gravity CC lot Actually term Balance Point BP accurate since purposes merely looking spot somewhere wing fore-andaft balance model Center Gravity actual center mass entire aircraft may located well above below wing may seem fine point matters some aerobatic maneuversmost especially rolls doesnt matter much current topic pitch stability isnt intention get huge involved technical discussion understanding few common terms might helpful Aerodynamic Center AC point action sum aerodynamic forces acting aircraft flight practical purposes fixed point does change airspeed position model air also sometimes referred Neutral Point AC individual airfoils falls very close 25% MAC Mean Aerodynamic Chord Finding point entire aircraft complicated business involves calculating individual ACs wing stab fin fuselage wheel pants etc adding vector addition since streamlined components stick out slipstream function wings some fashion purpose going say conventional aircraft AC almost always falls main wing between about 35-50% Mean Aerodynamic Chord Mean Aerodynamic Chord MAC just average chord width wing various ways find Its pretty simple wing constant-chord same width root tip simple tapered wings decent quick-and-dirty method just add root tip chords together divide two Move ruler around wing plan parallel wing centerline until find particular width mark called find percentage MAC calculate favorite units calculator February 1999 67 Chris Lakin starts Sukhoi 97 TOC rules allow 10% design deviation scale Chris obviously opted increasing tail moment arm Scratch-built original design Masters competitor Gary Fowler Auburn Washington Radio JR YS power model good performer abacus fingers-and-toes measure leading edge back Project line perpendicular chord line point centerline wing Bingo Yes know can add tip root root tip draw nice crisscross lines Im just lazy dont much feel like drawing diagram Pitch Stability stability lack same longitudinal fore-and-aft axis aircraft An aircraft has positive stability tends always settle down oscillation return line flight commanded position flight controls after being disturbed Think balancing ball bottom round bowl Neutral stability airplane has no tendency damp oscillations after being disturbed Think balancing ball sheet glass Negative stability tendency oscillations increase divergence Think balancing ball bottom inverted round bowl well-behaved aircraft size shape needs least some degree positive stability An aircraft may perfectly stable pitch unstable radioactive isotope roll yaw axis another story another time Moment Arm simple lever through force considered act aircraft Tail Moment Arm would distance AC wing AC stab Nose Moment Arm distance prop hub wing AC conventional layout practice people measure tail moment BP elevator hingeline about accurate usual government survey probably close enough horseshoes moment arms Stability comes degrees Some airplanes need stability others Trainers usually designed excess stability sport aircraft somewhat less aerobatic airplanes less Fun Fly-type aircraft typically have least stability time lay down some rules thumb aircraft stable pitch Balance Point must located front AC Neutral Point distance between two referred Static Margin bigger stab longer tail moment arm farther back AC will farther back BP can As static margin increased stability increases As stability increases control authority decreases entirely possible have too much stability situation becomes worse decaying airspeed Continued page 72 68 Model Aviation Dunphy longtime Pattern competitor official proprietor Precision Aero Composites strikes pose 98 Nats Real Shock Absorbing Action Straight Offset ONLY ROBART ROBOSTRUTS CARRY THE TST AIRCRAFT PERFORMANCE CERTI Best Replacement Wire Gear Big Performance Increase Sizes Right Any Model Easy Install Minutes Aircraft Grade Materials Robart Reliability direct replacement standard wire tear RoboStruta breeze install JIb increase performance bigcimel RoboStruts can also attached Robart other pneumatic retracts Strut Riaht Stuff Boho8tut625Robart Manufacturing Inc 5/8 Diam 1 8-50 lb ModelsPOBox 247 Dept StCharles IL 601 74 Phone 630-5847616 E-mail robart@robartcom right stuffon web @ httpllwwwrobortcorn Industry Leader Retractable Landing Ceor Fixed Scale Struts Control Horns 1-lingePoint Hinges Modeling Tools Morel Now 4 Sizes RoboStruts t real aircraft performance model live flohoStut38Gfunctioning oleo strut suspension Robart RoboStruts Smooth stick-to Boho$tut44Ocontrolled landings no bounce manufactured aircraft grade chrome floho$tut5GOmoly steel lightweight units attest proven Robart reliability performance YELLOW AIRCRAFT INTERNATIONAL Excellence Englnevlng Quality Manufacturing 203 Mass Ave Lexington MA 021734003 USA TEL 781674-9898 FAX 781674-2288 RC Aerobatics/Allison Continued page 68 enduring tenet RC nose-heavy models safe solid predictable iron-clad rule myth dont know times Ive seen models stall landing approach fall out sky simply because too nose-heavy works like maintain altitude forward flight wing must held positive-enough angle attack create lift thing doing holding horizontal stabilizer via elevator control nose-heavy model tail down-load up elevator takes keep wing biting air some point model slows airspeed over elevator decays control loses its ability keep wing proper angle attack elevator stall wing does what good positively cambered rigged wings want pitch down dumps lift Model impacts ground thud comedy errors often gets funnier wounded modeler immediately claims airplane balanced too far aft because nose-heavy airplanes dont stall actually adds weight nose Too-nose-heavy just bad tootail-heavy either will bend balsa Believe nose-heavy airplane will stall faster airspeed given same angle attack tail-heavy difference tailheavy airplane will stall nastily snap crunch nose-heavy airplane pitch down thud So far Pattern aerobatics goes think pilots would agree ideal Pattern airplane would almost neutral stability like able place aircraft precisely flight attitude have stay further input until command different flight attitude course some minimum amount positive stability must designed provide Email kingindustries@earthlinknet http//homeearthlinknet/4ingindustries/indexhtm SpinMaster aluminum spinner cones prop nuts available through manufacturer product precision made quality light weight performance made USA money back guarantee competitive prices cant go wrong owning SpinMaster product information place order visit web page phone fax toll free 1888-299-9476 FREE SHIPPING AND HANDLING USA Prop Nuts $599 ea Spinner Cones 3 -$2499 ea 25 in-$1699ea 225 -$1499 ea 72 Model Aviation 104~3da25dia25dia#2225dia AdapterKit Mfg King Industries 2924 E Eaton Dr Terre Haute IN 47802 $49500 DELUXE KIT FEATURES Fiberglass Fuselage Integral Vertical Fm Interform Recess-Molded Fiberglass Access Hatch Fiberglass Inlet Ducts Ready Install Fiberglass Exhaust Ducts Formers Bulkheads Precut Sanded Ready Install Balsa Presheeted Foam Core Wings Horizontal Stabs LE Installed Flaps Standard Feature Landing Gear Blocks Installed Wings Optional Plug Wings Vacuum Formed Clear Canopy Fiberglass Canopy Frame Also Available F/A18 Twin & Single F16 F4E A4 P38 P47 Spitfire ZERO AT-6 CAP-lOB Send $4 within USA $10 rest world PRODUCT INFO PACK damping prevent divergence dynamic instability designer trick get certain minimum amount no Too much positive stability aerobatic aircraft leads very high pilot workload nearly constant control input called just keep model trying return its primary trimmed condition otherwise known straight-and-level flight dont believe suggest spend some time trying fly 8-point roll trainer Generally speaking advantage have CU pretty far rear Pattern airplane dont stick back pretty far snap rolls spins arent possible let alone pretty important dont want have counteract overall nosedown pitching moment caused forward CU carrying up trim rerigging stab negative incidence wing positive want mainplane tailplane rigged nearly same angle thing airplane rolls inverted up trim becomes down trim Large angle-of-attack changes elevator deflections required hold airplane lineand case consecutive rolls better quick changes Knife-edge flight another case wing tail supposedly unloaded aerobatic designs too much difference between rigging angles wing tail excessive up elevator trim will show lateral pitch canopy same thing true vertical lines both up down might primary reason move CC around achieve level flight trim condition involves minimum difference incidence trim between mainplane tailplaneit simplifies minimizes other trim adjustments might need make such thrustline changes radio mixing primary flight controls purposes would like fairly aft CG main tailplanes rigged nearly identical angles plus dont want carry much trim level flight want airplane trim out hands-off stable horizon horizon Nice problem Unfortunately moving CU rear closer NP makes airplane skittish Pitch loads too light damping action decreased model easily disturbed gusts tends hunt rather groove Pitch stability has decreased regain lost static margin thus pitch stability have two main ways go can move CU forward can increase tail volume modern Pattern aircraft design solution over past decade has increase tail volume Tail volume moment arm times area increase either makes increase whole An increase both what see lot days accomplishes couple important things First increases tailplane efficiency longer lever arm increased area allow stabilizer effective both control damping Second increase tail volume moves Neutral Point aircraft rear Moving NP rear increasing tail volume regains static margin missing pitch stability BP can stay aft enough provide lively control response good spin/spin entries aircraft remains positively stable level flight damps well both knife-edges verticals behave themselves Hundreds thousands innocent trees have died providing raw material trimming charts articles published through sgd%PoT issue build 0 decidedly different tail feathers DAWs Foam P-51 D combat 2-hrs long slope soarer also eyeball Futaba s PA-I Pilot Assist Link device helping stabilize model lets master R/C flight & solo quickly Awesome hotSHOTS features X-1 rocketdropping B-29 brief visit Jet World Masters Swindon England awesome ducted fan Antonov ROT8 begin build ing robbes Millennium 60 helicopter aboutENGINES run Thunder Tigers honking 46H PRO ABC look YSs super trick 53 thumper Learn secrets using airbrush create professional look ing weathered effect FW1 90 Next add nay landing lights DC-3 cover story add flaps Hanger 9s hot new ARE Cessna 182 Skylane ask local hobby dealer Sheldons Hobbies 8001822-1688 National Hobby Supply 800/437-2736 Hobby Barn8001324-4910 Tammies Hobbies800/521-5614 HobbyTown USAwwwhobbytowncom Phone 507 268-4084 FAX 507 268-3245 Its international call must first dial 011 www modelsport com February 1999 75 HANDS ON PRO-BOW THIS UNWUEDEVICEALLOWS YOU TO CUT ACCU RATE WING CORES WITHOUT EXPENSIVE AND COMPLICATED EQUIPMENT WITH THE PRO-BOW THE CUTTING WIRE IS GUIDED DIRECTLY AT THE TEMPLATES BY HAND HELD INSULATOR CLIPS THE HEAVY-DUTY CONSTRUCTION GIVES GOOD FEEL TO THE BOW AND WITH THE ADJUSTABLE HEAT PROBE THE WIRE TEMPERATURE CAN BE CONTROLLED FOR PERFECT CUTTING RESULTS sale $4999 WORKS DIRECTLY OFF OF 12 VOLT BATTERY OR 10 AMP BATTERY CHARGER S COMPLETELY ASSEMBLED STRAIGHT DR TAPERED CORES IAL PASSIVE RESISTANCE CUTTING WIRE LATED STEEL FRAME CUTTING TECHNIQUES & OPERATING INSTRUCTIONS INCLUDED UP TO 41 SEND $500 FOR 60 PAGE CATALOG VISA ERCARD ACCEP TEDADD $500 SHIPPING IN USAIL RESIDENTS ADD 725% TAX WING MFG306 E SIMMONSGALESBURG IL 61401 visit us http//wwwwingmfgcomCALL 309-342-3009 years worth noting cookbooks BP location CG first last main item checked rechecked changed manipulated because affects aircraft flight modes bears other trim adjustment might make Nothing important Unfortunately some kits come appropriate location plainly marked some just show range others show nothing Some models acquired already built sans plans Much has written about fine-tuning BP during flight testing get close enough safely fine-tune Try recipe works allows try out understanding terms defined above Measure tail moment arm mean aerodynamic chord calculate areas both wing stab Assuming stab average size 20-25% wing area divide moment arm MAC number get 275 larger set BP 33-35% MAC number 25 275 set 28-32% Smaller 25 set BP 25-28% MAC stab smaller average shade numbers low side range BP further forward stab larger average reverse true good initial placement BP 99% time will get close wont need move again method good Pattern models symmetrical airfoils also works almost common flat-bottom semisymmetrical airfoils see RC So go ahead figure out wing like just before fly may take few hours time thats cheap compared new models antidepressants psychotherapy 1 0 40 Size ARF wood construction wieg tail tips covered Oracover Germany tasy assemble easy repair Flat bottom air toil Sayer otable characteriotics make perfect tsr new pilots Feel tank wheels landing gear spinner hardware etc incladed Radio esquires 4 C5 wins Span 04 Wins Area 720 sq Piping WI 00 05 ne 40 40 3d1 Combo JL-316 wfilrunder Tiger GP-42 Eagine$13999 IVn Super Cemba add HiTec Focus 4 ch FM Radio$26499 Thunder Tiger 4060 size Tgo T ane tombas pease call far price descniptien High quality lowest price Americal F4U Corsair 40 Size ARFP 51 Mustang 40 Size ARF intheUSA 0 $i89~ Radro nequres 4 h 0 servos span asRadio nequires 5 cs 5 servosl wins span 07eadin nequires 4 cs winn span 040 Wing Wing Area 035 sq ns Wi 03 lbs wino Area 005 sq ng wt 0 ibsArea 520 in. Fiping Wt 52 ibs ungine 40unsine 40 uin l2c sr 4a gine 40- 03 cuin l2c 53 75 14C 3 con 2c 40-70 dc Optien piece Option Painted piece P/g cowi $2109instailed retractsPlO dovi $1999 Combo Pro46 tagine$26699Combo Prs46 Engine$26899Combo Pro46 Engine$25699 w/F-54S 40 Engine 99w/F-545 40 Engine 99w/F-54S 40 Engine 99 Twin Sukhoi Sport ARFUltimate 30 Size ARFCap 231 40 Size AFIF Made USA nadin Onquirns 4 co Span 070 Wing Radio nequires 4 co Wing Span 4t 7 Radio Requires 4 co 10 servos Wing Span 50 Area 070 sq ng Wt 90 ibs ungine IwoArea 570 sq Fiving wt 44 iSo ne 35-in Wing Area 550 sq Piping Wt 59 iSo 40 -53 coin 201 tao 40 054040 coin 2cl 53 4CEngine 40 53 ruin 3d 00-90 4c Combo with 2 Prs46 Engineo $48399 Combo Pro46 Engine 699 Combo Pro46 Engine - $26699 w/2 F-545 4C tngneo$62799wlF-545 40 Engine $29999w/F-915 40 Engine $37999 Super Chipmuok 60 Size ARFUltimate 120 AFIF $2A9 Radio Requires 0 cs 7 servos Span 04 in wing Area sq ng wt 00 iSo Engine 001201 St 4c Prn-instaiied retracts $389 ard tiaps Radio Requires 4 h 5 servos Span onRadio Requires 4 cs 5 servos wing Span 5$ in Area 075 sq ng Wt 92 Combo ProOl tngine 699 Wing Area 1013 no Wt 05 iSo Engine 90- t go coin Oc t 20 40wIF-Ol $ 40 Engine 99Engine tOO tOO coin 40 Engine Special Thunder Tiger Aircraft Engine / GP-15 . $4595Pro-4ii 99 GP-25$4999Pro-46 99 GP-42$5499Pro-fl 999Au Oils Pre-covered reai heat-shrink GP-61 99Pro-120 99poipester tiiv Onaconer tiny Sermany $500 500 Pro-25 9F54S 14C1 $16899Oversite bones higher 000 cash Snip Add gOOg Pro 36 9F-91S 14C $20999 1/6 Scale Cub ARF $120 Radio Requires 400 5 servos Wing Spar 71 wing Area 008 sq in. Piping WI 32 iSa ne 40-53 cv 40 Combs wIF-OlS 40 Engine 1/4 Scale Cub AFIF $429Y Radio Requires 4 0h5 servos Span 104 in Wing Area 1012 sq ir Piping WI 149 iSo Engine 120-150 cv 40 RIC SERVICE AT ITS BEST Sales Service Anything Radio Controlled KMI 7420 Seven Mile Rd Northville Michigan 48167 Ph 248-486-4800 Fax 248-486-1603 Winner RIC HobbiesORDERS ONLY 800780-0100 15437 Proctor Aye Hacienda Hts CA 91745lotormation 626-961-4616 626-330-9351 wwwWinnerRCcom Repairs Updates Custom Modifications Frequency Changes 6 Send Legal sized SAE 1997 Meter conversions ACE Airtronics Aristo-craft Cirrus EK Catalog containing lists RIC maintenance hints Futaba Hitec Heathkit Hobby Shack JR Kraft KGL KSE Kline Discover MCard VISA COD KoPropo Pro-Line RCD Tower Hobbies World Engines & others UPS USMAIL FEDEX etc Calibrated Equipment Quick Turnaround Walk-in daily service 800 am-500 pm Send E-Mail PTWaters@junocom February 1999 77