Free Flight: Duration

DURATION Bob Meuser CONTROLLED warps Warps can good bad occur want unlikely will occur want thats bad Most Free Flight models employ washout wingtips wing tip panels twisted tips lower angle incidence rest wings Three degrees typical value Some claim tip washout substitutes dihedral models dont have dihedral some Scale models have never quite able figure out should true dont accept explanations Ive seen seems work Another favorite intentional warp washin part wing inside turn model flies right/left right climb left glide poses problem wing inside during climb outside during glide Ill bet could have figures Out yourself So isnt surprising models fly right/left left/right seldom employ kind warp Rather extreme amounts differential warp sometimes employed models fly right/right however Mild amounts em ployed Towline Gliders almost always used Indoor models own being exceptions works inside wing travels slower outside wing must have area differential chord lateral offset Indoor models must fly higher angle attack higher angle attack can supplied warping inside wing higher angle incidence isnt done wing symmetrical no lateral offset differ ential chord model will sideslip combined effect dihedral sideslip will make angle attack greater inside wing laws equilibrium must satisfied workswashin inside wing panel slow speeds increased angle attack inside wing compensates slower speed wing supposed Also added drag hauls model around proper direction choke little part argu ment seems work higher speeds inside wing contributes lift its share prevents model spiral-diving ground unless offset rudder wins out So much what warps supposed now onward problem get warps want recent article Gregory Thomas appeared Minneapolis Modeler published Minneapolis Model Aero Club Minneapolis addresses weighty issue own usual method suffici ently similar testify method works although seems go about somewhat orderly fashion wing panel rudder stab built flat model covered usual fashion tissue Prior water-shrinking doping aug built indicated sketches tissue sprayed water water-plus-alcohol surface immediately plopped jig stays until dry Give coat dope quickly plop jig again too slow dope has dried bit before manage get buttoned thejig apply coat dope thinner After last coat dope let surface stay jig long possible Parts jig contact doped surfaces waxed covered Teflon tape prevent surface sticking jig 52 Model Aviation Praibuilt Sherman Gillespie Peck-Polymers kit suit competition popular Embryo Endurance event works just dandy structures have little torsional stiffness other supplied covering box spar diagonal rib construction used warps must built framework before covered torsionally limp frameworks think building warps structure has slight edge over building flat warping structure afterwardand just happen have solution hip pocket solution Celotex Thats local trade name havent faintest idea what generic term would Maybe insulation board RAIcM comes 4 x 8-ft panels -in thick used covering walls ceilings soft can push pin clear through makes easy thumbs bit flimsy large piece will warp under its own weight small pieces stay pretty flat larger pieces can tacked plywood thought mainly useful building board Delta Darts such until started using itit really nice stuffi Start chunk stuff several inches larger model surface building Nail down piece -in plywood workbench dining-room table whatevers handy before mash nails home insert shims get warps want recently built Scale model wing way curved dihedral prototype flat wing figure judges will think curve got accidentally tip washout inboardwing washin built Celotex surface Stick plans build frame warps built structure Use same rig after covering water later dope drying nothing its little problems dog simply loves eat Celotex Thats bad part good part its cheaper dog food. Electronic timers Since integrated circuit chips became available decade ago modelers have attempted develop electronic timers replace mechanical timers fuses engine cutoff dethermalizer actuation incentive has potentially accurate timing higher reliability compared mechanical clockwork timers problem electronic timers has electronics per se actuator Small electric motors electro magnets etc tend bulky heavy power Continued page 122 February 1981 53 Billy Henn gets lots practice towing witn tnis moaitieu iCnop R- towliner dad Bill simplified wing structure design John Thornhills cheapie electric-power FF bird uses tlaalo nack ungeared motor battery used Polaroid SX-70 film pack Note motor attached duct tape battery nestles underthe wing top pylon Sharp eyes will see fuse-operated Ia OT hand-bent wire battery switch below pylon all-balsa bird world-beaterjust lots fun N U U f7EiT7J Strips Balsa Fuzz-Freew/out Adjustments Small -$1000 Large shown-$2000 Please add $100 postage P Kits ature Renlicas EE BEE $600 please ad Si 00 postage Catalog 75 GENE DUBOIS P0 Box c Acuslinet MA 02743 ....DEALER INQUIRIES INVITED 4 Fine Quality Flying Models 98 RUBBER POWER KITS plus Gliders CIL R/C Accessories Books Catalog $150 MAJESTIC MODELS 3273 West 129th Street Cleveland Ohio 44111 adjustment per flight go slowly Sensitivity adjustments increases speed Increase DT time fine-tune glide until satisfied Sea Power contribution state art Free Flight hope enjoy introduction programmable tail feathers FF Duration/Meuser Continued page 53 hungry According Bat Sheet Strat-O-Bats Wash ington Steve Helmick editor Ken Bauer pro ducing electronic timers Nordic Towline Gliders perhaps multi-function timer Power models will come later havent chance check information Ken get photos drawings Helmicks comments Bauers timer look like way go all-weatherA-2 calm-air zoom delay desirable glider does work Basically theres steel plate fastened DT line stuck onto electro-magnet made coil relay Some electronic wizardry IC chip times current flow coil shuts down DT-time comes row tiny rocker switches sets DT time. assigned times 10 40 160 640 seconds flyoffs automatically add together r words punch 40 160 200 sec pretty windy 10 160 170 seconds etc Punch get 850 rockers have hole can slip heavy monofilament pin through lock what want lock out what dont want first rocker switch row just on/off Also micro-switch put front towhook allows timer reset return straight tow go circle tow timer starts means circle less 10-sec setting timer starts model goes CT mode neat thing about drop towline line breaks timer starts model comes down battery goes dead model DTs less chance setting DT too short because no grooves count Seelig timer will speed up weather gets hotter Seeligs lost about 20-30 seconds afternoon heat Taft Ken recommends 9v transistor radio battery power weight about 1 oz battery timer itself quite small light nose pod will probably have specially tailored Bauer timer Oh yes . $25 please interested write Ken Bauer 627 E Monroe Orange CA 92667 Now Tatone no longer imports timers bit problem Seelig timers available expensive Some English companies having timers made Hong Kong dont know available US Some modelers Northwest using Tomy windup toy motors engine cutoff Id like supply details dont have running time too short DT actuation According Aero Modeller magazine some English Free Flighters extending running time two minutes adding inertia escapement heat tip glass-head pin push plastic escapement andprestotwo minutes still doesnt solve problem Category II flying Perhaps abandon clockspring use rubberband-string-and pulley system K-Mart timers still available preferred modelers over Tatone type engine timers have manufacture own faceplate release mechanism See AA Lidbergs article 122 Model Aviation Yes rush copy new 6th edition Radio Control Buyers Guide Please check ElEnclosed $1100 $995 retail plus $105 postage US Canada Only dians send US Funds El Charge El Mastercharge LI Visa City State Zip Return R/C Buyers GuIde 7 Clifton House Clifton VA 22024 5- 34][b739232701319810]] NO NONSENSE BALSA STRIPPERS N ATTACKER good-looking foam plane ex cellent fun-fly contests Big thick wing washout make docile yet maneuverable Illustrated plans much hardware & large full color decal sheet Wing Span 48 Construc tion All-Foam Radio 4 Channel Engine 1940 4995 SWEET STIK simple build & fun flying model Larger version popular Das Little Stik Full-size plans & much hardware cluding motor mounts & hinges Wing Span 54 Construction All-Balsa Ra dio 4 Channel Engine 1940 T-cRAFr stand-off scale model offering tb best flight performance Kit build quickly contains full-size plans de tailed instruction booklet vacuum formec cowl & wheel parts & much hardware Wing Span 55-1/2 Con struction Balsa Radio 4 4995Channel Engine 2945 Send 50 complete cataloq MIDWEST PRODUCTS COMPANY 400 S Indiana Street Hobart Indiana 46342 August 1980 issue ModelAviation since cameras made nowadays have built-in timerselectronic ones thatthe whole mechanical-timer industry has collapsed decreasing need add-on timers Id bet days K-Mart timers numbered Towline glider youngster holding glider photo Billy Henn has big rubber-power Scale models number years story model father Bill has same body rudder stab two Tchop A-2s also same B6356 airfoil thing different wing little too much expect 14-year-old assemble 450 parts designed simpler structure sheeted top surface quite strong has good torsional rigidity weighs 170 grams responds beautifully tow Billy gets some great zoom launches model seems have no negative characteristics Billy lot circle-tow practice field safe 20-sec flights usually model brought down towline attached Well lot sort practice sure beats no practice Stab hold-down simple open hook end DT string often bad news DT actuates stap pops up bounces hits its limit stopoften bouncing right out hook solution make closed bend hook snaps over loop stab takes rather long hook sometimes get enough springy itand long hook may compatible other features south end aircraft Bob Norten Bakersfield CA gets required springy tweaking couple loops hook using round-nose pliers shown sketch beat high cost electric propulsion number readers have clued used batteries Polaroid SX-70 camera potential power sources model aircraftpropul sion battery built film pack come end film pack among entrails get replacing old new used battery isnt much used still plenty life left Since battery free save price set expensive ni-cad batteries right off bat since cant recharged save price charger Thats two strikes against conventional electric propulsion systems already Ive barely started Hah what about cost special computer-designed high-output geared motor youll need Forget gears little doubt geared motor-prop setup can beat pants off ungeared rig ultimate FF performance gears can live suitable motor can obtained Radio Shack buck Look 6-volt motors sometimes have cylindrical affair about 13/16-in diameter marked Mabuchi RE14 plastic back cover designation doesnt tell much about motor except size back plate motors same back plate can have variety voltage ratings type brushes etc particular Radio Shack motor have has sheet-metal brushes likely live very long under strenuous service John Thomhill has messed around SX-70 batteries Radio Shack motors some success battery simply wrapped around front fuselage Perhaps could build hollow pylon slip battery inside Bah sophisticated Anyhow electric propulsion doesnt have sophisticated expensive bunch AMA National Records ElectricPower models sitting just waiting broken Ceiling-effect Pennyplane sketch shows perhaps-noc-all-that-crazy-after-all brainstorm got after writing up item Hewitt Phillips ceiling-effect Cat Indoor Helicopter recordsetting machine Ceiling effect sort like ground effect down-side up real wing attracted image sees itself reflected ceiling tip vortexes produced HO B BYM IDE AWAYHO IBYB IDE AWAYHO BBYH IDEAWAYI-lO IBYHI SE AWAY FAMOUS BRITISH DIESELS AEROMODELLER February 1981 123 PLANS CATALOG-DIESEL HANUBUOK S 300 pp HOBBY HIDE WAY VANIL 309 244-7389 61734 HOIBYHIDEAWAYHOBBYHIDEAWAYHABBYHIDEAWAYHOIBYHIOEAW New Westchester County Center Whfte Plains York Dont miss 13th annual show Itll biggest best ever Keep next last weekend February open. 1981 WRAMs Show going larg est yet Well over 150 manu facturers other exhibiters have already signed up bring everything thats new hobby. kits engines radios accessories everything between famous Swap Shop will full operation thousands items including built-up planes almost new radios engines on something just about everyone Static Competition Make sure latest creation finished up polished youll have chance take home ot dozens trophies offered events ww POST WW MIIvryl POST WW NoOMltaryI PATTERN SPORT BIPLANE OLO TIMERS SPORT PYLON OLIOERS HELICOPTERS SCALER C BOATS RACINOR CBOATS STANO-OEV SCALE JUNIOR EVENTS R CCARS BE ST IN-SHOW Judging takes place Sunday afternoon Entries accepted until 12 Noon Sunday SWAP SHOP WRAMs Swap Shop has bBcome major Show attractions thousands indi vidual items Changing handaTo help eliminate registration crush 1981 Swap Shop will provide pre regist ration forms receive forms send self-addressed stamped envelope John labiater 4 Devon Rd Larchmont NY 10528 SPECIAL NOTE Because increased volume items being brought Swap Shop combined space limita tions built-up model will accepted Swap Shop registrant further information write Larry DiRubbo 167 Lindsey Ave. Buchanan NY 10511 914 739-2827 wESTCHESnER RADIO AEROMODELERS INC February 21/22 Wescvesie corny COIHe S oS,IaIIy bodied , o1yo1 WHie PIOHS Hr aiifle,ieSecio, 0f RI IIHCenirelPaOAee dIOHO doe pdOeaao WHie 0aoss osi22miles,oIHoINYC Make Glow el [ 1hA 1/4 Scale Power1 Usable Power Greater Send 4O & Stamped Addressed Envelope Dealer Inquiry InvIted Davis Diesel Development Inc LPJBox 141 Milford CT 06460 real image wings partially cancel other induced drag reduced recently heard someone decades ago put wheel top cabane microfilm model achieve same result perhaps lesser degree closer get wing ceiling better dihedral out Perhaps large vertical fin installed between wing struts bit ofleft wing wheels will required prevent excessive skidding principle could applied virtually Indoor classes except perhaps Ornithopter Oh dam large very flat ceiling fundamental requirement goes saying OK lads wholl first get sanction official AMA meet beheld own living room 10AM 6 PM Reminder National Free Flight Society soliciting papers 1981 Symposium pub lication Papers should cover some aspect science art Free Flight models Send abstract proposed paper immediately Jim Bennett 324 Helfenstein Ave St Louis MO 63119 Bob Meuser 4200 Gregory St Oakland CA 94619 SAFE FLYING IS NO ACCIDENT Safety Comes First/Preston Continued page 72 Because since 1974 eight people have died direct result flying CL models cases model control lines contacted overhead power distribution lines death electro cution result three additional inci dents severe burns flier result recent incidents occurred April 1980 Safety First column February 1980 issue ModelAviation discussed electrocution incidents length may wondering being brought attention second time Consider following situation lawsuit stemmed 1975 incident recently settled substantial settlement made against number hobby manufac turers arguments decided case control line handle designed prevent type incident happening other words handle should have insulated flier control lines and/or model question now being asked whether feasible practical have no doubt non-conductive lines would solve problem think CL fliers would agree no such lines currently market would provide necessary insulation same time retain strength control precision steel lines An alternative would consider insulated control handle Although Im humble mechanical engineer would venture say would solve problem say based facts incident verbally related authoratative source incident CL model being flown site bordered power lines flier standing point placed model least 250 feet lines its closest point Nevertheless arc jumped power lines model resulting severed control lines severe burns flier Power company officials arrived scene after incident refused believe model never closer 250 feet power lines light incident find hard believe few inches high dielectric material might result insulating handle would sufficient provide necessary protection opinion expert needed resolve question Such expert could either member AMA Safety Committee consultant committee Another potentially hazardous situation could resolved Safety Committee involves black propellers Reports finger lacerations invisible running black propellers continue trickle latest report received Model Aviation just two weeks ago involved incident required surgery re-attach severed extensor tendons finger Would painting tips such propellers white yellow solve problem Should man ufacturers propellers asked copy column being sent members AMA Executive Council together request reconsider need establishment AMA Safety Committee Ifyou have opinions subject either pro con either contact District VP its safety safety fellow modelers concerned about John Preston 7012 Elvira Court Falls Churclp VA 22042 124 Model Aviation SHOW 81 FF CONTEST WINNERS WA Witch Hawk 1979 NATS 1st PL Win ner record setter A-B Witch Hawk 1980 NATS 1st PL winner Class B Plans $600 PP A-A kit $1400 pIus 10% post age Two kits postage paid Clemcra fr p 0 Box 524 Sand Springs OK 74063

DURATION Bob Meuser CONTROLLED warps Warps can good bad occur want unlikely will occur want thats bad Most Free Flight models employ washout wingtips wing tip panels twisted tips lower angle incidence rest wings Three degrees typical value Some claim tip washout substitutes dihedral models dont have dihedral some Scale models have never quite able figure out should true dont accept explanations Ive seen seems work Another favorite intentional warp washin part wing inside turn model flies right/left right climb left glide poses problem wing inside during climb outside during glide Ill bet could have figures Out yourself So isnt surprising models fly right/left left/right seldom employ kind warp Rather extreme amounts differential warp sometimes employed models fly right/right however Mild amounts em ployed Towline Gliders almost always used Indoor models own being exceptions works inside wing travels slower outside wing must have area differential chord lateral offset Indoor models must fly higher angle attack higher angle attack can supplied warping inside wing higher angle incidence isnt done wing symmetrical no lateral offset differ ential chord model will sideslip combined effect dihedral sideslip will make angle attack greater inside wing laws equilibrium must satisfied workswashin inside wing panel slow speeds increased angle attack inside wing compensates slower speed wing supposed Also added drag hauls model around proper direction choke little part argu ment seems work higher speeds inside wing contributes lift its share prevents model spiral-diving ground unless offset rudder wins out So much what warps supposed now onward problem get warps want recent article Gregory Thomas appeared Minneapolis Modeler published Minneapolis Model Aero Club Minneapolis addresses weighty issue own usual method suffici ently similar testify method works although seems go about somewhat orderly fashion wing panel rudder stab built flat model covered usual fashion tissue Prior water-shrinking doping aug built indicated sketches tissue sprayed water water-plus-alcohol surface immediately plopped jig stays until dry Give coat dope quickly plop jig again too slow dope has dried bit before manage get buttoned thejig apply coat dope thinner After last coat dope let surface stay jig long possible Parts jig contact doped surfaces waxed covered Teflon tape prevent surface sticking jig 52 Model Aviation Praibuilt Sherman Gillespie Peck-Polymers kit suit competition popular Embryo Endurance event works just dandy structures have little torsional stiffness other supplied covering box spar diagonal rib construction used warps must built framework before covered torsionally limp frameworks think building warps structure has slight edge over building flat warping structure afterwardand just happen have solution hip pocket solution Celotex Thats local trade name havent faintest idea what generic term would Maybe insulation board RAIcM comes 4 x 8-ft panels -in thick used covering walls ceilings soft can push pin clear through makes easy thumbs bit flimsy large piece will warp under its own weight small pieces stay pretty flat larger pieces can tacked plywood thought mainly useful building board Delta Darts such until started using itit really nice stuffi Start chunk stuff several inches larger model surface building Nail down piece -in plywood workbench dining-room table whatevers handy before mash nails home insert shims get warps want recently built Scale model wing way curved dihedral prototype flat wing figure judges will think curve got accidentally tip washout inboardwing washin built Celotex surface Stick plans build frame warps built structure Use same rig after covering water later dope drying nothing its little problems dog simply loves eat Celotex Thats bad part good part its cheaper dog food. Electronic timers Since integrated circuit chips became available decade ago modelers have attempted develop electronic timers replace mechanical timers fuses engine cutoff dethermalizer actuation incentive has potentially accurate timing higher reliability compared mechanical clockwork timers problem electronic timers has electronics per se actuator Small electric motors electro magnets etc tend bulky heavy power Continued page 122 February 1981 53 Billy Henn gets lots practice towing witn tnis moaitieu iCnop R- towliner dad Bill simplified wing structure design John Thornhills cheapie electric-power FF bird uses tlaalo nack ungeared motor battery used Polaroid SX-70 film pack Note motor attached duct tape battery nestles underthe wing top pylon Sharp eyes will see fuse-operated Ia OT hand-bent wire battery switch below pylon all-balsa bird world-beaterjust lots fun N U U f7EiT7J Strips Balsa Fuzz-Freew/out Adjustments Small -$1000 Large shown-$2000 Please add $100 postage P Kits ature Renlicas EE BEE $600 please ad Si 00 postage Catalog 75 GENE DUBOIS P0 Box c Acuslinet MA 02743 ....DEALER INQUIRIES INVITED 4 Fine Quality Flying Models 98 RUBBER POWER KITS plus Gliders CIL R/C Accessories Books Catalog $150 MAJESTIC MODELS 3273 West 129th Street Cleveland Ohio 44111 adjustment per flight go slowly Sensitivity adjustments increases speed Increase DT time fine-tune glide until satisfied Sea Power contribution state art Free Flight hope enjoy introduction programmable tail feathers FF Duration/Meuser Continued page 53 hungry According Bat Sheet Strat-O-Bats Wash ington Steve Helmick editor Ken Bauer pro ducing electronic timers Nordic Towline Gliders perhaps multi-function timer Power models will come later havent chance check information Ken get photos drawings Helmicks comments Bauers timer look like way go all-weatherA-2 calm-air zoom delay desirable glider does work Basically theres steel plate fastened DT line stuck onto electro-magnet made coil relay Some electronic wizardry IC chip times current flow coil shuts down DT-time comes row tiny rocker switches sets DT time. assigned times 10 40 160 640 seconds flyoffs automatically add together r words punch 40 160 200 sec pretty windy 10 160 170 seconds etc Punch get 850 rockers have hole can slip heavy monofilament pin through lock what want lock out what dont want first rocker switch row just on/off Also micro-switch put front towhook allows timer reset return straight tow go circle tow timer starts means circle less 10-sec setting timer starts model goes CT mode neat thing about drop towline line breaks timer starts model comes down battery goes dead model DTs less chance setting DT too short because no grooves count Seelig timer will speed up weather gets hotter Seeligs lost about 20-30 seconds afternoon heat Taft Ken recommends 9v transistor radio battery power weight about 1 oz battery timer itself quite small light nose pod will probably have specially tailored Bauer timer Oh yes . $25 please interested write Ken Bauer 627 E Monroe Orange CA 92667 Now Tatone no longer imports timers bit problem Seelig timers available expensive Some English companies having timers made Hong Kong dont know available US Some modelers Northwest using Tomy windup toy motors engine cutoff Id like supply details dont have running time too short DT actuation According Aero Modeller magazine some English Free Flighters extending running time two minutes adding inertia escapement heat tip glass-head pin push plastic escapement andprestotwo minutes still doesnt solve problem Category II flying Perhaps abandon clockspring use rubberband-string-and pulley system K-Mart timers still available preferred modelers over Tatone type engine timers have manufacture own faceplate release mechanism See AA Lidbergs article 122 Model Aviation Yes rush copy new 6th edition Radio Control Buyers Guide Please check ElEnclosed $1100 $995 retail plus $105 postage US Canada Only dians send US Funds El Charge El Mastercharge LI Visa City State Zip Return R/C Buyers GuIde 7 Clifton House Clifton VA 22024 5- 34][b739232701319810]] NO NONSENSE BALSA STRIPPERS N ATTACKER good-looking foam plane ex cellent fun-fly contests Big thick wing washout make docile yet maneuverable Illustrated plans much hardware & large full color decal sheet Wing Span 48 Construc tion All-Foam Radio 4 Channel Engine 1940 4995 SWEET STIK simple build & fun flying model Larger version popular Das Little Stik Full-size plans & much hardware cluding motor mounts & hinges Wing Span 54 Construction All-Balsa Ra dio 4 Channel Engine 1940 T-cRAFr stand-off scale model offering tb best flight performance Kit build quickly contains full-size plans de tailed instruction booklet vacuum formec cowl & wheel parts & much hardware Wing Span 55-1/2 Con struction Balsa Radio 4 4995Channel Engine 2945 Send 50 complete cataloq MIDWEST PRODUCTS COMPANY 400 S Indiana Street Hobart Indiana 46342 August 1980 issue ModelAviation since cameras made nowadays have built-in timerselectronic ones thatthe whole mechanical-timer industry has collapsed decreasing need add-on timers Id bet days K-Mart timers numbered Towline glider youngster holding glider photo Billy Henn has big rubber-power Scale models number years story model father Bill has same body rudder stab two Tchop A-2s also same B6356 airfoil thing different wing little too much expect 14-year-old assemble 450 parts designed simpler structure sheeted top surface quite strong has good torsional rigidity weighs 170 grams responds beautifully tow Billy gets some great zoom launches model seems have no negative characteristics Billy lot circle-tow practice field safe 20-sec flights usually model brought down towline attached Well lot sort practice sure beats no practice Stab hold-down simple open hook end DT string often bad news DT actuates stap pops up bounces hits its limit stopoften bouncing right out hook solution make closed bend hook snaps over loop stab takes rather long hook sometimes get enough springy itand long hook may compatible other features south end aircraft Bob Norten Bakersfield CA gets required springy tweaking couple loops hook using round-nose pliers shown sketch beat high cost electric propulsion number readers have clued used batteries Polaroid SX-70 camera potential power sources model aircraftpropul sion battery built film pack come end film pack among entrails get replacing old new used battery isnt much used still plenty life left Since battery free save price set expensive ni-cad batteries right off bat since cant recharged save price charger Thats two strikes against conventional electric propulsion systems already Ive barely started Hah what about cost special computer-designed high-output geared motor youll need Forget gears little doubt geared motor-prop setup can beat pants off ungeared rig ultimate FF performance gears can live suitable motor can obtained Radio Shack buck Look 6-volt motors sometimes have cylindrical affair about 13/16-in diameter marked Mabuchi RE14 plastic back cover designation doesnt tell much about motor except size back plate motors same back plate can have variety voltage ratings type brushes etc particular Radio Shack motor have has sheet-metal brushes likely live very long under strenuous service John Thomhill has messed around SX-70 batteries Radio Shack motors some success battery simply wrapped around front fuselage Perhaps could build hollow pylon slip battery inside Bah sophisticated Anyhow electric propulsion doesnt have sophisticated expensive bunch AMA National Records ElectricPower models sitting just waiting broken Ceiling-effect Pennyplane sketch shows perhaps-noc-all-that-crazy-after-all brainstorm got after writing up item Hewitt Phillips ceiling-effect Cat Indoor Helicopter recordsetting machine Ceiling effect sort like ground effect down-side up real wing attracted image sees itself reflected ceiling tip vortexes produced HO B BYM IDE AWAYHO IBYB IDE AWAYHO BBYH IDEAWAYI-lO IBYHI SE AWAY FAMOUS BRITISH DIESELS AEROMODELLER February 1981 123 PLANS CATALOG-DIESEL HANUBUOK S 300 pp HOBBY HIDE WAY VANIL 309 244-7389 61734 HOIBYHIDEAWAYHOBBYHIDEAWAYHABBYHIDEAWAYHOIBYHIOEAW New Westchester County Center Whfte Plains York Dont miss 13th annual show Itll biggest best ever Keep next last weekend February open. 1981 WRAMs Show going larg est yet Well over 150 manu facturers other exhibiters have already signed up bring everything thats new hobby. kits engines radios accessories everything between famous Swap Shop will full operation thousands items including built-up planes almost new radios engines on something just about everyone Static Competition Make sure latest creation finished up polished youll have chance take home ot dozens trophies offered events ww POST WW MIIvryl POST WW NoOMltaryI PATTERN SPORT BIPLANE OLO TIMERS SPORT PYLON OLIOERS HELICOPTERS SCALER C BOATS RACINOR CBOATS STANO-OEV SCALE JUNIOR EVENTS R CCARS BE ST IN-SHOW Judging takes place Sunday afternoon Entries accepted until 12 Noon Sunday SWAP SHOP WRAMs Swap Shop has bBcome major Show attractions thousands indi vidual items Changing handaTo help eliminate registration crush 1981 Swap Shop will provide pre regist ration forms receive forms send self-addressed stamped envelope John labiater 4 Devon Rd Larchmont NY 10528 SPECIAL NOTE Because increased volume items being brought Swap Shop combined space limita tions built-up model will accepted Swap Shop registrant further information write Larry DiRubbo 167 Lindsey Ave. Buchanan NY 10511 914 739-2827 wESTCHESnER RADIO AEROMODELERS INC February 21/22 Wescvesie corny COIHe S oS,IaIIy bodied , o1yo1 WHie PIOHS Hr aiifle,ieSecio, 0f RI IIHCenirelPaOAee dIOHO doe pdOeaao WHie 0aoss osi22miles,oIHoINYC Make Glow el [ 1hA 1/4 Scale Power1 Usable Power Greater Send 4O & Stamped Addressed Envelope Dealer Inquiry InvIted Davis Diesel Development Inc LPJBox 141 Milford CT 06460 real image wings partially cancel other induced drag reduced recently heard someone decades ago put wheel top cabane microfilm model achieve same result perhaps lesser degree closer get wing ceiling better dihedral out Perhaps large vertical fin installed between wing struts bit ofleft wing wheels will required prevent excessive skidding principle could applied virtually Indoor classes except perhaps Ornithopter Oh dam large very flat ceiling fundamental requirement goes saying OK lads wholl first get sanction official AMA meet beheld own living room 10AM 6 PM Reminder National Free Flight Society soliciting papers 1981 Symposium pub lication Papers should cover some aspect science art Free Flight models Send abstract proposed paper immediately Jim Bennett 324 Helfenstein Ave St Louis MO 63119 Bob Meuser 4200 Gregory St Oakland CA 94619 SAFE FLYING IS NO ACCIDENT Safety Comes First/Preston Continued page 72 Because since 1974 eight people have died direct result flying CL models cases model control lines contacted overhead power distribution lines death electro cution result three additional inci dents severe burns flier result recent incidents occurred April 1980 Safety First column February 1980 issue ModelAviation discussed electrocution incidents length may wondering being brought attention second time Consider following situation lawsuit stemmed 1975 incident recently settled substantial settlement made against number hobby manufac turers arguments decided case control line handle designed prevent type incident happening other words handle should have insulated flier control lines and/or model question now being asked whether feasible practical have no doubt non-conductive lines would solve problem think CL fliers would agree no such lines currently market would provide necessary insulation same time retain strength control precision steel lines An alternative would consider insulated control handle Although Im humble mechanical engineer would venture say would solve problem say based facts incident verbally related authoratative source incident CL model being flown site bordered power lines flier standing point placed model least 250 feet lines its closest point Nevertheless arc jumped power lines model resulting severed control lines severe burns flier Power company officials arrived scene after incident refused believe model never closer 250 feet power lines light incident find hard believe few inches high dielectric material might result insulating handle would sufficient provide necessary protection opinion expert needed resolve question Such expert could either member AMA Safety Committee consultant committee Another potentially hazardous situation could resolved Safety Committee involves black propellers Reports finger lacerations invisible running black propellers continue trickle latest report received Model Aviation just two weeks ago involved incident required surgery re-attach severed extensor tendons finger Would painting tips such propellers white yellow solve problem Should man ufacturers propellers asked copy column being sent members AMA Executive Council together request reconsider need establishment AMA Safety Committee Ifyou have opinions subject either pro con either contact District VP its safety safety fellow modelers concerned about John Preston 7012 Elvira Court Falls Churclp VA 22042 124 Model Aviation SHOW 81 FF CONTEST WINNERS WA Witch Hawk 1979 NATS 1st PL Win ner record setter A-B Witch Hawk 1980 NATS 1st PL winner Class B Plans $600 PP A-A kit $1400 pIus 10% post age Two kits postage paid Clemcra fr p 0 Box 524 Sand Springs OK 74063