ELI WLYJ2LiWEIDJ Ever see water jet streaming out Free Flight model author took new product development New Yorkbased toy manufacturer chance go high profile something daring fun HAnk Donde WATER-POWERED aircraft thought Model airplanes already powered fire internal combustion earth rubber Isnt time bring aqua stuff propulsion picture Also die-hard Free Flighter have often dreamed converting countrys millions kids beloved hobby before theyre permanently bewitched video games cousin RC models summer 1986 became responsible developing new toys mass market Director Engineering UN Toys Corporation New York City time $300 million toy manufacturer ET Gotcha Gun fame saw chance fulfill long-held fantasy idea proposed concepts design group marry water reaction motor explained below form jet propulsion five-footwingspan Free Flight model concept looked attractive marketing group ventured predict annual sales volume two three million models Already imagining AMA NFFS memberships soaring Once Id convinced everyone project viable remained design airplane piece cake right Wrong 35 years Free Flight modeling under belt no idea what getting modeler prima donna supposed expert what makes Free Flight model go lets start beginning Propulsion After few trials 22 Model Aviation Ready launch its first successful flight Jammin Jet climbed about 15 seconds transitioned 42 seconds beautiful soaring altitude gain over 100 feet author sprltely-looking waterfueled Free Flight design foamed poly styrene airframe has five-foot wingspan wing area 300 square inches Jammin Jet kit Intended kids innovative design produced 1987-88 UN Toys Corporation Note foamed polystyrene three-piece wing fuselage plastic soda bottle motor/fuel tank air pump nozzle/screw-on valve author shows simple plug-In wing tips foamed polystyrene wing TA L PIVOT S ACE 0 0 E SWIVEL 07 10 DFRGE DOWEL F RUBBER BOLOS RIGHT EV C DC AL SE DE 00 COCA OVER ONE WAY VA ~ WOTOR 00 G AT O OE A- CQULER- ONEWAD OALAESET TO LEAR AR 00 P51 $040 ORIFICE LEO TABEVBVBZiZ ----JAMMIN JETS WATER POWERED MODEL AIRPLANE FASRIC COKE ROTTLE RATED TO RUPOERE AR 100 P51DESIONED WV AR 00900NEW VORAND CAVE AOEIIBELEASED BEFORE LABUCADRAWN BY AL WROBO AGOYT 1987 GATE SW NOD OPEL AT LAUNEB DUE TO WATER PRESSORE BOBBER EAO brainstorming sessions design group narrowed its focus motor/fuel tank thought would work concept simple Wed start 12-oz plastic soda bottle half fill plain old tap water manually pump up other half air remember ordinary bicycle pump 60 psi bottle rated 160 psi rapture pressure screw-on valve designed ensure leakage some rascal try overpressurize bottle corner gas station 60-ft steel cable strung six feet high along lab accept pulley/carriage gizmo soda bottle motor hung bottle pumped up testing began duration distance acceleration weight rate water discharge thrust After some iterative refinements miles videotape decided nozzle diameter 004 data collected indicated jet run 13 16 seconds initial velocity 20 30 feet per second up 20 ounces thrust water jet eruption spectacular toyand drenching So far testing turned up nothing new What conventional reaction motor Water jet momentum exchanged model momentum propelling aircraft forward Time vs thrust curves indicated nonlinear decay expected compressed gas/water mixture released through small orifice aka exhaust pipe initial high burst rapid 10% total motor run decay knee followed longer shallower 60% decay sudden drop zero As well know after 25 years experience flying rubber-powered models time history released energy stored wound rubber can mathematically modeled after perfect gas behavior yet failed detect similarities first blind spot time arrived successful model configuration support new product almost ran out read gets better Configurationairframe design data thrust duration estimated Continued page 75 24 Model Aviation Made 12-az plastic soda bottle motor/fuel tank has 004-in-diameter noz zle screw-on valve ensures leakage case overpressurization fle motorfluel tank halt tilled water soda bottle motor/tank nozzle pumped bicycle pump 160 psi bicycle pump air hose nozzle Above Installing motor four inches forward center-of-gravity setting jet thrust line 1 below CG 22 rd angle achieves nicely controlled climb low water jet efflux still strongly concentrated model begins its climb DE MAR 21Dover DE E KCAM 11th Annual Auction 1200 Noon Regiafration 1000AM lo cated theather wing Blue Hen Mall Rt 13 $100 registration fee & 10% commission formation call Charles Sterner 302878 0618 Sponsor KENT COUNTY AEROMODELERS TX MAR 28Weatherford TX E Aeromodeling Society Swap Meet & Auction 8AM New Larger Local ion Auction 1PM Half Jr High School 902 Charles $5 Admission fee includes door prizes & raffle Free tables 10% Auction Fee Call Sandy Frank 817-S99-7131 info & direc lions Sponsor WEATHERFORD AEROMOD ELING SOCIETY pIOMq ~SWAP MEET & AUCTION f NEW LARGER TION iSaturday Maeeh 28 1992 Hall Jr High School SWAPMEETSaos-Naan r AUCTION Noon-4 pot 902 Charlro StL Weatherfoed Tenao 76086 ALL ACTIVITIES WI THIN THE SAME BUILDING Admission includes 5 Raffle Tickets Adotisaiso 5 Day Unlimited Free Swap Space 10 Auction Fee kCvvvvvvvvv4w WI MAR 28Oshkosh WI E EM Air Adventure Museum 5th Model Airplane Show Modelers Display types airplanes Plastic RIC among museums lull-scale aircraft Share fel lowship see museum displays Admision discount displaying models Contact Carl Swickley 414-428-4800 Sponsor WINNE BAGO RIC FLYERS TIff Aero Modelers ~ March 27 29 1992 ALL RB MODULE WELCOME U CIa.. Tesphla RAPPLE 1 cas d plasm VIDEOS AND PICTURES Infurmailon contact e~ see-sees APRIL Jammin/Donde Continued page 24 weights hand came up design looked attractive flyable Since fueled-up motor/tank weighed nearly 9 oz available initial thrust about 20 oz made 5-ft-wingspan 300-sq-in-wing-area airframe classic Unlimited Rubberstrange eh foamed polystyrene 2-1W/cu-ft density yielded all-up weight 12 14 ounces add structural integrity durability insert-molded Y16-diameter spruce dowels main spars wing fuselage Engine location orientation next task install jet engine ye olde valved soda bottle correct location Thinking problem through gave priority fact motor also fuel tank fuel water will depleted 15 seconds after launch shaving 7 oz off models weight important thing thought keep center-of-gravity stable fuel exhausted since fluctuating CG would affect models trim end situated motor just jettisonable auxiliary tank full-scale jet fighter locatedprecisely under center-of-gravity logical enough reasoning far went problem still overlooking similarities between design Rubber models Failure late July 1987 ad hoc flight test section UN Toy Company headed flying field public park South Hackensack New Jersey test fly aquaplane Cameras ready motor pumped up last check surfaces wind direction launched Nothing ship went out straight almost level gained about 10 feet altitude before jet stream became exhausted nosed down landed Total flight time about 20 seconds did few test flights no better results worst nightmares substantiated toy model dud humbled aura greatness vanished During next two weeks mass produced some 20 models hot-wire-cut sanded videotaped miles disastrous flights hopes stirred now catching thermal stayed work late night watching reflight videotapes slow motion Still nothing meantime wed acquired faithful jeering audience park folks waited daily afternoon flops staged water jet plane will never fly gang early August either succeed tool up mass production million models Christmas season scrap project August 15 happens birthday set drop-dead date Solution Back drawing board reinspected thrust graphs weight data searched equations elusive flaws wing loading too large available thrust simply insufficient thrust Finally light bulb came thrust-time history similar wound rubber torque-time history being case similarity must extend trimming Bingo could h8ve missed Determining models center-of-gravity location three-dimensional problem CG must situated around pitch axis lateral axis balance nose tail also around roll axis longitudinal axis models especially parasol high-wing onesif push pins through tail nose longitudinal axis craft will roll Unlike rubber motor however expends its energy retains its weight water jet motor expends both energy weight reconcile fact conventional approach locating CG solution set motor thrust line below center-of-gravity position motor/fuel tank forward rather CG motor thrust line set below CO model pitches up briefly stalls climb thrust quickly diminishes other hand because motor/fuel tank forward rather coincident CG model becomes nose-heavy wants dive both nose-up moment nose-down moment present As fuel water depleted nose lightens nose-down moment decreases since thrust also decays nose-up moment lessens well could match rates decay two moments make nose-up moments decline lag behind nose-down moments tad nicely controlled net climb would result took long discover Im sure Perhaps overzealousness about projects potential made little light-headed After performing some calculations matching graphs moved motor/fuel tank four inches forward CG set jet thrust line 1 below CG 228 upward angle Success last faithful afternoon crowd Vice President Sales hand out give last heave launched ship climbed 15 secondspostflight videotapes showed altitude gain over 100 feetand genfly transitioned 42 seconds beautiful soaring couldnt have better birthday present Continued page 85 February 1992 75 6TH ANNUAL WESTERN FLYERS RIO AUCTION 4/5/82 IN SPRINGFIELD NERS NEAR OMAHA OVER 122000 TO BE SOLDI $1000 RAFFLE LARGEST AUCTION IN MID WESTIIIII FOR INFO BOB BOUMSTEIN BSU S 165TH AVE OMAHA NE 68130 Over next few weeks company manufactured nearly 50 models christened Jammin Jets Madison Avenue advertising agency engineer technician salesman out learning fly Some novice fliers achieved durations half minutes benefit thermals improve power phase emulated delayed prop release Wakefield modifying valve water jet does start until model has launched way stored energy fully utilized Production next step tooling Since foam molding done cast aluminum cavities molds wood pattern must first fabricated surprise master patternmakers Massachusetts-based pattern shop assigned work turned out old-time modeler nice break since no problems communicating technical happy ending Concurrenfly tooling other preparation mass production another dose fun came way company agreed back sales effort childrens prime-time TV ad campaign job produce 30-second commercial same New York advertising agency dreamed up models name selected compose jingle score prepare story line Hollywood company filmed commercial location Osmond Brothers studios Provo Utah engineering group supplied models production technical support built test flew 50 models enlisted Scott Croizier Cleveland Ohio build two electrically powered RC airplanes Jammin Jet silhouette intended flybys remote filming end RC models used lot fun flying child actors no idea launch Free Flight model trained spot Most caught within hour became engrossed impromptu contests arranged filming yielded 18000 feet celluloid 3000 feet selected Accompanied captivating theme song High Can Fly 30-second commercial showed bunch kids rising sun backs flying Jammin Jet against Utah mountain horizon beautiful spectacularand successful million half models shipped next year Free Flight forever article dedicated late good friend Scott Croizier Free Flight modeler well family man professional pilot brave spirit Scott left us last yearE Flying Fun/Mathews Continued page 31 leading edge above trailing edge datum line drawn other words Clark Y section would call flat bottomed very Continued page 86 PLUG IN WINGS / ADVANCED FULL SYMETRICAL AIRFOIL / RATED FOR ALL MANEUVERS INCLUDING MAXIMUM G PULL UPS / CLEAN AERODYNAMIC DESIGN IS FAST STABLE AND EFFICIENT TM z 2 0 0 0 C 4 4 0 n Wingspan 47Area 460 sq 2 Assembly Time 6 hrs mas Lenght 42Weight 475-500 lb PRE-ASSEMBLED AND INSTALLED HAYES MOUNT NOSEGEAN 8 OZ HAYES TANK SULUVAN SKYLITE WHEELS SULLIVAN PUSHROOS CONTROL HORNS GAPLESS HINGES ALL AROUND February 1992 85 nomenclatureairfoil washout angle Jammin/Dondeincidence etc Continued page 75 COMPLETELY ASSEMBLED & FINISHED OUT OF THE BOX NO GLUE PAINT OR COVERING REQUIRED INSTALL YOUR RADIO 35-46 ENGINE AND PROP AT THE FIELD COMPUTER DESIGNED & BUILT BY MIT AEROSPACE ENGINEERS INCREDIBLE FLIGHT PERFORMANCE AND QUALITY BUILT-IN Hi-G introduces theMhUIIISUhUiI 0 VISA & MC Accepted Orders & Info 602-788-5209 H -G 2131 E Crocus Dr Phoenix AZ 85022
Edition: Model Aviation - 1992/02
Page Numbers: 22, 23, 24, 75, 85
ELI WLYJ2LiWEIDJ Ever see water jet streaming out Free Flight model author took new product development New Yorkbased toy manufacturer chance go high profile something daring fun HAnk Donde WATER-POWERED aircraft thought Model airplanes already powered fire internal combustion earth rubber Isnt time bring aqua stuff propulsion picture Also die-hard Free Flighter have often dreamed converting countrys millions kids beloved hobby before theyre permanently bewitched video games cousin RC models summer 1986 became responsible developing new toys mass market Director Engineering UN Toys Corporation New York City time $300 million toy manufacturer ET Gotcha Gun fame saw chance fulfill long-held fantasy idea proposed concepts design group marry water reaction motor explained below form jet propulsion five-footwingspan Free Flight model concept looked attractive marketing group ventured predict annual sales volume two three million models Already imagining AMA NFFS memberships soaring Once Id convinced everyone project viable remained design airplane piece cake right Wrong 35 years Free Flight modeling under belt no idea what getting modeler prima donna supposed expert what makes Free Flight model go lets start beginning Propulsion After few trials 22 Model Aviation Ready launch its first successful flight Jammin Jet climbed about 15 seconds transitioned 42 seconds beautiful soaring altitude gain over 100 feet author sprltely-looking waterfueled Free Flight design foamed poly styrene airframe has five-foot wingspan wing area 300 square inches Jammin Jet kit Intended kids innovative design produced 1987-88 UN Toys Corporation Note foamed polystyrene three-piece wing fuselage plastic soda bottle motor/fuel tank air pump nozzle/screw-on valve author shows simple plug-In wing tips foamed polystyrene wing TA L PIVOT S ACE 0 0 E SWIVEL 07 10 DFRGE DOWEL F RUBBER BOLOS RIGHT EV C DC AL SE DE 00 COCA OVER ONE WAY VA ~ WOTOR 00 G AT O OE A- CQULER- ONEWAD OALAESET TO LEAR AR 00 P51 $040 ORIFICE LEO TABEVBVBZiZ ----JAMMIN JETS WATER POWERED MODEL AIRPLANE FASRIC COKE ROTTLE RATED TO RUPOERE AR 100 P51DESIONED WV AR 00900NEW VORAND CAVE AOEIIBELEASED BEFORE LABUCADRAWN BY AL WROBO AGOYT 1987 GATE SW NOD OPEL AT LAUNEB DUE TO WATER PRESSORE BOBBER EAO brainstorming sessions design group narrowed its focus motor/fuel tank thought would work concept simple Wed start 12-oz plastic soda bottle half fill plain old tap water manually pump up other half air remember ordinary bicycle pump 60 psi bottle rated 160 psi rapture pressure screw-on valve designed ensure leakage some rascal try overpressurize bottle corner gas station 60-ft steel cable strung six feet high along lab accept pulley/carriage gizmo soda bottle motor hung bottle pumped up testing began duration distance acceleration weight rate water discharge thrust After some iterative refinements miles videotape decided nozzle diameter 004 data collected indicated jet run 13 16 seconds initial velocity 20 30 feet per second up 20 ounces thrust water jet eruption spectacular toyand drenching So far testing turned up nothing new What conventional reaction motor Water jet momentum exchanged model momentum propelling aircraft forward Time vs thrust curves indicated nonlinear decay expected compressed gas/water mixture released through small orifice aka exhaust pipe initial high burst rapid 10% total motor run decay knee followed longer shallower 60% decay sudden drop zero As well know after 25 years experience flying rubber-powered models time history released energy stored wound rubber can mathematically modeled after perfect gas behavior yet failed detect similarities first blind spot time arrived successful model configuration support new product almost ran out read gets better Configurationairframe design data thrust duration estimated Continued page 75 24 Model Aviation Made 12-az plastic soda bottle motor/fuel tank has 004-in-diameter noz zle screw-on valve ensures leakage case overpressurization fle motorfluel tank halt tilled water soda bottle motor/tank nozzle pumped bicycle pump 160 psi bicycle pump air hose nozzle Above Installing motor four inches forward center-of-gravity setting jet thrust line 1 below CG 22 rd angle achieves nicely controlled climb low water jet efflux still strongly concentrated model begins its climb DE MAR 21Dover DE E KCAM 11th Annual Auction 1200 Noon Regiafration 1000AM lo cated theather wing Blue Hen Mall Rt 13 $100 registration fee & 10% commission formation call Charles Sterner 302878 0618 Sponsor KENT COUNTY AEROMODELERS TX MAR 28Weatherford TX E Aeromodeling Society Swap Meet & Auction 8AM New Larger Local ion Auction 1PM Half Jr High School 902 Charles $5 Admission fee includes door prizes & raffle Free tables 10% Auction Fee Call Sandy Frank 817-S99-7131 info & direc lions Sponsor WEATHERFORD AEROMOD ELING SOCIETY pIOMq ~SWAP MEET & AUCTION f NEW LARGER TION iSaturday Maeeh 28 1992 Hall Jr High School SWAPMEETSaos-Naan r AUCTION Noon-4 pot 902 Charlro StL Weatherfoed Tenao 76086 ALL ACTIVITIES WI THIN THE SAME BUILDING Admission includes 5 Raffle Tickets Adotisaiso 5 Day Unlimited Free Swap Space 10 Auction Fee kCvvvvvvvvv4w WI MAR 28Oshkosh WI E EM Air Adventure Museum 5th Model Airplane Show Modelers Display types airplanes Plastic RIC among museums lull-scale aircraft Share fel lowship see museum displays Admision discount displaying models Contact Carl Swickley 414-428-4800 Sponsor WINNE BAGO RIC FLYERS TIff Aero Modelers ~ March 27 29 1992 ALL RB MODULE WELCOME U CIa.. Tesphla RAPPLE 1 cas d plasm VIDEOS AND PICTURES Infurmailon contact e~ see-sees APRIL Jammin/Donde Continued page 24 weights hand came up design looked attractive flyable Since fueled-up motor/tank weighed nearly 9 oz available initial thrust about 20 oz made 5-ft-wingspan 300-sq-in-wing-area airframe classic Unlimited Rubberstrange eh foamed polystyrene 2-1W/cu-ft density yielded all-up weight 12 14 ounces add structural integrity durability insert-molded Y16-diameter spruce dowels main spars wing fuselage Engine location orientation next task install jet engine ye olde valved soda bottle correct location Thinking problem through gave priority fact motor also fuel tank fuel water will depleted 15 seconds after launch shaving 7 oz off models weight important thing thought keep center-of-gravity stable fuel exhausted since fluctuating CG would affect models trim end situated motor just jettisonable auxiliary tank full-scale jet fighter locatedprecisely under center-of-gravity logical enough reasoning far went problem still overlooking similarities between design Rubber models Failure late July 1987 ad hoc flight test section UN Toy Company headed flying field public park South Hackensack New Jersey test fly aquaplane Cameras ready motor pumped up last check surfaces wind direction launched Nothing ship went out straight almost level gained about 10 feet altitude before jet stream became exhausted nosed down landed Total flight time about 20 seconds did few test flights no better results worst nightmares substantiated toy model dud humbled aura greatness vanished During next two weeks mass produced some 20 models hot-wire-cut sanded videotaped miles disastrous flights hopes stirred now catching thermal stayed work late night watching reflight videotapes slow motion Still nothing meantime wed acquired faithful jeering audience park folks waited daily afternoon flops staged water jet plane will never fly gang early August either succeed tool up mass production million models Christmas season scrap project August 15 happens birthday set drop-dead date Solution Back drawing board reinspected thrust graphs weight data searched equations elusive flaws wing loading too large available thrust simply insufficient thrust Finally light bulb came thrust-time history similar wound rubber torque-time history being case similarity must extend trimming Bingo could h8ve missed Determining models center-of-gravity location three-dimensional problem CG must situated around pitch axis lateral axis balance nose tail also around roll axis longitudinal axis models especially parasol high-wing onesif push pins through tail nose longitudinal axis craft will roll Unlike rubber motor however expends its energy retains its weight water jet motor expends both energy weight reconcile fact conventional approach locating CG solution set motor thrust line below center-of-gravity position motor/fuel tank forward rather CG motor thrust line set below CO model pitches up briefly stalls climb thrust quickly diminishes other hand because motor/fuel tank forward rather coincident CG model becomes nose-heavy wants dive both nose-up moment nose-down moment present As fuel water depleted nose lightens nose-down moment decreases since thrust also decays nose-up moment lessens well could match rates decay two moments make nose-up moments decline lag behind nose-down moments tad nicely controlled net climb would result took long discover Im sure Perhaps overzealousness about projects potential made little light-headed After performing some calculations matching graphs moved motor/fuel tank four inches forward CG set jet thrust line 1 below CG 228 upward angle Success last faithful afternoon crowd Vice President Sales hand out give last heave launched ship climbed 15 secondspostflight videotapes showed altitude gain over 100 feetand genfly transitioned 42 seconds beautiful soaring couldnt have better birthday present Continued page 85 February 1992 75 6TH ANNUAL WESTERN FLYERS RIO AUCTION 4/5/82 IN SPRINGFIELD NERS NEAR OMAHA OVER 122000 TO BE SOLDI $1000 RAFFLE LARGEST AUCTION IN MID WESTIIIII FOR INFO BOB BOUMSTEIN BSU S 165TH AVE OMAHA NE 68130 Over next few weeks company manufactured nearly 50 models christened Jammin Jets Madison Avenue advertising agency engineer technician salesman out learning fly Some novice fliers achieved durations half minutes benefit thermals improve power phase emulated delayed prop release Wakefield modifying valve water jet does start until model has launched way stored energy fully utilized Production next step tooling Since foam molding done cast aluminum cavities molds wood pattern must first fabricated surprise master patternmakers Massachusetts-based pattern shop assigned work turned out old-time modeler nice break since no problems communicating technical happy ending Concurrenfly tooling other preparation mass production another dose fun came way company agreed back sales effort childrens prime-time TV ad campaign job produce 30-second commercial same New York advertising agency dreamed up models name selected compose jingle score prepare story line Hollywood company filmed commercial location Osmond Brothers studios Provo Utah engineering group supplied models production technical support built test flew 50 models enlisted Scott Croizier Cleveland Ohio build two electrically powered RC airplanes Jammin Jet silhouette intended flybys remote filming end RC models used lot fun flying child actors no idea launch Free Flight model trained spot Most caught within hour became engrossed impromptu contests arranged filming yielded 18000 feet celluloid 3000 feet selected Accompanied captivating theme song High Can Fly 30-second commercial showed bunch kids rising sun backs flying Jammin Jet against Utah mountain horizon beautiful spectacularand successful million half models shipped next year Free Flight forever article dedicated late good friend Scott Croizier Free Flight modeler well family man professional pilot brave spirit Scott left us last yearE Flying Fun/Mathews Continued page 31 leading edge above trailing edge datum line drawn other words Clark Y section would call flat bottomed very Continued page 86 PLUG IN WINGS / ADVANCED FULL SYMETRICAL AIRFOIL / RATED FOR ALL MANEUVERS INCLUDING MAXIMUM G PULL UPS / CLEAN AERODYNAMIC DESIGN IS FAST STABLE AND EFFICIENT TM z 2 0 0 0 C 4 4 0 n Wingspan 47Area 460 sq 2 Assembly Time 6 hrs mas Lenght 42Weight 475-500 lb PRE-ASSEMBLED AND INSTALLED HAYES MOUNT NOSEGEAN 8 OZ HAYES TANK SULUVAN SKYLITE WHEELS SULLIVAN PUSHROOS CONTROL HORNS GAPLESS HINGES ALL AROUND February 1992 85 nomenclatureairfoil washout angle Jammin/Dondeincidence etc Continued page 75 COMPLETELY ASSEMBLED & FINISHED OUT OF THE BOX NO GLUE PAINT OR COVERING REQUIRED INSTALL YOUR RADIO 35-46 ENGINE AND PROP AT THE FIELD COMPUTER DESIGNED & BUILT BY MIT AEROSPACE ENGINEERS INCREDIBLE FLIGHT PERFORMANCE AND QUALITY BUILT-IN Hi-G introduces theMhUIIISUhUiI 0 VISA & MC Accepted Orders & Info 602-788-5209 H -G 2131 E Crocus Dr Phoenix AZ 85022
Edition: Model Aviation - 1992/02
Page Numbers: 22, 23, 24, 75, 85
ELI WLYJ2LiWEIDJ Ever see water jet streaming out Free Flight model author took new product development New Yorkbased toy manufacturer chance go high profile something daring fun HAnk Donde WATER-POWERED aircraft thought Model airplanes already powered fire internal combustion earth rubber Isnt time bring aqua stuff propulsion picture Also die-hard Free Flighter have often dreamed converting countrys millions kids beloved hobby before theyre permanently bewitched video games cousin RC models summer 1986 became responsible developing new toys mass market Director Engineering UN Toys Corporation New York City time $300 million toy manufacturer ET Gotcha Gun fame saw chance fulfill long-held fantasy idea proposed concepts design group marry water reaction motor explained below form jet propulsion five-footwingspan Free Flight model concept looked attractive marketing group ventured predict annual sales volume two three million models Already imagining AMA NFFS memberships soaring Once Id convinced everyone project viable remained design airplane piece cake right Wrong 35 years Free Flight modeling under belt no idea what getting modeler prima donna supposed expert what makes Free Flight model go lets start beginning Propulsion After few trials 22 Model Aviation Ready launch its first successful flight Jammin Jet climbed about 15 seconds transitioned 42 seconds beautiful soaring altitude gain over 100 feet author sprltely-looking waterfueled Free Flight design foamed poly styrene airframe has five-foot wingspan wing area 300 square inches Jammin Jet kit Intended kids innovative design produced 1987-88 UN Toys Corporation Note foamed polystyrene three-piece wing fuselage plastic soda bottle motor/fuel tank air pump nozzle/screw-on valve author shows simple plug-In wing tips foamed polystyrene wing TA L PIVOT S ACE 0 0 E SWIVEL 07 10 DFRGE DOWEL F RUBBER BOLOS RIGHT EV C DC AL SE DE 00 COCA OVER ONE WAY VA ~ WOTOR 00 G AT O OE A- CQULER- ONEWAD OALAESET TO LEAR AR 00 P51 $040 ORIFICE LEO TABEVBVBZiZ ----JAMMIN JETS WATER POWERED MODEL AIRPLANE FASRIC COKE ROTTLE RATED TO RUPOERE AR 100 P51DESIONED WV AR 00900NEW VORAND CAVE AOEIIBELEASED BEFORE LABUCADRAWN BY AL WROBO AGOYT 1987 GATE SW NOD OPEL AT LAUNEB DUE TO WATER PRESSORE BOBBER EAO brainstorming sessions design group narrowed its focus motor/fuel tank thought would work concept simple Wed start 12-oz plastic soda bottle half fill plain old tap water manually pump up other half air remember ordinary bicycle pump 60 psi bottle rated 160 psi rapture pressure screw-on valve designed ensure leakage some rascal try overpressurize bottle corner gas station 60-ft steel cable strung six feet high along lab accept pulley/carriage gizmo soda bottle motor hung bottle pumped up testing began duration distance acceleration weight rate water discharge thrust After some iterative refinements miles videotape decided nozzle diameter 004 data collected indicated jet run 13 16 seconds initial velocity 20 30 feet per second up 20 ounces thrust water jet eruption spectacular toyand drenching So far testing turned up nothing new What conventional reaction motor Water jet momentum exchanged model momentum propelling aircraft forward Time vs thrust curves indicated nonlinear decay expected compressed gas/water mixture released through small orifice aka exhaust pipe initial high burst rapid 10% total motor run decay knee followed longer shallower 60% decay sudden drop zero As well know after 25 years experience flying rubber-powered models time history released energy stored wound rubber can mathematically modeled after perfect gas behavior yet failed detect similarities first blind spot time arrived successful model configuration support new product almost ran out read gets better Configurationairframe design data thrust duration estimated Continued page 75 24 Model Aviation Made 12-az plastic soda bottle motor/fuel tank has 004-in-diameter noz zle screw-on valve ensures leakage case overpressurization fle motorfluel tank halt tilled water soda bottle motor/tank nozzle pumped bicycle pump 160 psi bicycle pump air hose nozzle Above Installing motor four inches forward center-of-gravity setting jet thrust line 1 below CG 22 rd angle achieves nicely controlled climb low water jet efflux still strongly concentrated model begins its climb DE MAR 21Dover DE E KCAM 11th Annual Auction 1200 Noon Regiafration 1000AM lo cated theather wing Blue Hen Mall Rt 13 $100 registration fee & 10% commission formation call Charles Sterner 302878 0618 Sponsor KENT COUNTY AEROMODELERS TX MAR 28Weatherford TX E Aeromodeling Society Swap Meet & Auction 8AM New Larger Local ion Auction 1PM Half Jr High School 902 Charles $5 Admission fee includes door prizes & raffle Free tables 10% Auction Fee Call Sandy Frank 817-S99-7131 info & direc lions Sponsor WEATHERFORD AEROMOD ELING SOCIETY pIOMq ~SWAP MEET & AUCTION f NEW LARGER TION iSaturday Maeeh 28 1992 Hall Jr High School SWAPMEETSaos-Naan r AUCTION Noon-4 pot 902 Charlro StL Weatherfoed Tenao 76086 ALL ACTIVITIES WI THIN THE SAME BUILDING Admission includes 5 Raffle Tickets Adotisaiso 5 Day Unlimited Free Swap Space 10 Auction Fee kCvvvvvvvvv4w WI MAR 28Oshkosh WI E EM Air Adventure Museum 5th Model Airplane Show Modelers Display types airplanes Plastic RIC among museums lull-scale aircraft Share fel lowship see museum displays Admision discount displaying models Contact Carl Swickley 414-428-4800 Sponsor WINNE BAGO RIC FLYERS TIff Aero Modelers ~ March 27 29 1992 ALL RB MODULE WELCOME U CIa.. Tesphla RAPPLE 1 cas d plasm VIDEOS AND PICTURES Infurmailon contact e~ see-sees APRIL Jammin/Donde Continued page 24 weights hand came up design looked attractive flyable Since fueled-up motor/tank weighed nearly 9 oz available initial thrust about 20 oz made 5-ft-wingspan 300-sq-in-wing-area airframe classic Unlimited Rubberstrange eh foamed polystyrene 2-1W/cu-ft density yielded all-up weight 12 14 ounces add structural integrity durability insert-molded Y16-diameter spruce dowels main spars wing fuselage Engine location orientation next task install jet engine ye olde valved soda bottle correct location Thinking problem through gave priority fact motor also fuel tank fuel water will depleted 15 seconds after launch shaving 7 oz off models weight important thing thought keep center-of-gravity stable fuel exhausted since fluctuating CG would affect models trim end situated motor just jettisonable auxiliary tank full-scale jet fighter locatedprecisely under center-of-gravity logical enough reasoning far went problem still overlooking similarities between design Rubber models Failure late July 1987 ad hoc flight test section UN Toy Company headed flying field public park South Hackensack New Jersey test fly aquaplane Cameras ready motor pumped up last check surfaces wind direction launched Nothing ship went out straight almost level gained about 10 feet altitude before jet stream became exhausted nosed down landed Total flight time about 20 seconds did few test flights no better results worst nightmares substantiated toy model dud humbled aura greatness vanished During next two weeks mass produced some 20 models hot-wire-cut sanded videotaped miles disastrous flights hopes stirred now catching thermal stayed work late night watching reflight videotapes slow motion Still nothing meantime wed acquired faithful jeering audience park folks waited daily afternoon flops staged water jet plane will never fly gang early August either succeed tool up mass production million models Christmas season scrap project August 15 happens birthday set drop-dead date Solution Back drawing board reinspected thrust graphs weight data searched equations elusive flaws wing loading too large available thrust simply insufficient thrust Finally light bulb came thrust-time history similar wound rubber torque-time history being case similarity must extend trimming Bingo could h8ve missed Determining models center-of-gravity location three-dimensional problem CG must situated around pitch axis lateral axis balance nose tail also around roll axis longitudinal axis models especially parasol high-wing onesif push pins through tail nose longitudinal axis craft will roll Unlike rubber motor however expends its energy retains its weight water jet motor expends both energy weight reconcile fact conventional approach locating CG solution set motor thrust line below center-of-gravity position motor/fuel tank forward rather CG motor thrust line set below CO model pitches up briefly stalls climb thrust quickly diminishes other hand because motor/fuel tank forward rather coincident CG model becomes nose-heavy wants dive both nose-up moment nose-down moment present As fuel water depleted nose lightens nose-down moment decreases since thrust also decays nose-up moment lessens well could match rates decay two moments make nose-up moments decline lag behind nose-down moments tad nicely controlled net climb would result took long discover Im sure Perhaps overzealousness about projects potential made little light-headed After performing some calculations matching graphs moved motor/fuel tank four inches forward CG set jet thrust line 1 below CG 228 upward angle Success last faithful afternoon crowd Vice President Sales hand out give last heave launched ship climbed 15 secondspostflight videotapes showed altitude gain over 100 feetand genfly transitioned 42 seconds beautiful soaring couldnt have better birthday present Continued page 85 February 1992 75 6TH ANNUAL WESTERN FLYERS RIO AUCTION 4/5/82 IN SPRINGFIELD NERS NEAR OMAHA OVER 122000 TO BE SOLDI $1000 RAFFLE LARGEST AUCTION IN MID WESTIIIII FOR INFO BOB BOUMSTEIN BSU S 165TH AVE OMAHA NE 68130 Over next few weeks company manufactured nearly 50 models christened Jammin Jets Madison Avenue advertising agency engineer technician salesman out learning fly Some novice fliers achieved durations half minutes benefit thermals improve power phase emulated delayed prop release Wakefield modifying valve water jet does start until model has launched way stored energy fully utilized Production next step tooling Since foam molding done cast aluminum cavities molds wood pattern must first fabricated surprise master patternmakers Massachusetts-based pattern shop assigned work turned out old-time modeler nice break since no problems communicating technical happy ending Concurrenfly tooling other preparation mass production another dose fun came way company agreed back sales effort childrens prime-time TV ad campaign job produce 30-second commercial same New York advertising agency dreamed up models name selected compose jingle score prepare story line Hollywood company filmed commercial location Osmond Brothers studios Provo Utah engineering group supplied models production technical support built test flew 50 models enlisted Scott Croizier Cleveland Ohio build two electrically powered RC airplanes Jammin Jet silhouette intended flybys remote filming end RC models used lot fun flying child actors no idea launch Free Flight model trained spot Most caught within hour became engrossed impromptu contests arranged filming yielded 18000 feet celluloid 3000 feet selected Accompanied captivating theme song High Can Fly 30-second commercial showed bunch kids rising sun backs flying Jammin Jet against Utah mountain horizon beautiful spectacularand successful million half models shipped next year Free Flight forever article dedicated late good friend Scott Croizier Free Flight modeler well family man professional pilot brave spirit Scott left us last yearE Flying Fun/Mathews Continued page 31 leading edge above trailing edge datum line drawn other words Clark Y section would call flat bottomed very Continued page 86 PLUG IN WINGS / ADVANCED FULL SYMETRICAL AIRFOIL / RATED FOR ALL MANEUVERS INCLUDING MAXIMUM G PULL UPS / CLEAN AERODYNAMIC DESIGN IS FAST STABLE AND EFFICIENT TM z 2 0 0 0 C 4 4 0 n Wingspan 47Area 460 sq 2 Assembly Time 6 hrs mas Lenght 42Weight 475-500 lb PRE-ASSEMBLED AND INSTALLED HAYES MOUNT NOSEGEAN 8 OZ HAYES TANK SULUVAN SKYLITE WHEELS SULLIVAN PUSHROOS CONTROL HORNS GAPLESS HINGES ALL AROUND February 1992 85 nomenclatureairfoil washout angle Jammin/Dondeincidence etc Continued page 75 COMPLETELY ASSEMBLED & FINISHED OUT OF THE BOX NO GLUE PAINT OR COVERING REQUIRED INSTALL YOUR RADIO 35-46 ENGINE AND PROP AT THE FIELD COMPUTER DESIGNED & BUILT BY MIT AEROSPACE ENGINEERS INCREDIBLE FLIGHT PERFORMANCE AND QUALITY BUILT-IN Hi-G introduces theMhUIIISUhUiI 0 VISA & MC Accepted Orders & Info 602-788-5209 H -G 2131 E Crocus Dr Phoenix AZ 85022
Edition: Model Aviation - 1992/02
Page Numbers: 22, 23, 24, 75, 85
ELI WLYJ2LiWEIDJ Ever see water jet streaming out Free Flight model author took new product development New Yorkbased toy manufacturer chance go high profile something daring fun HAnk Donde WATER-POWERED aircraft thought Model airplanes already powered fire internal combustion earth rubber Isnt time bring aqua stuff propulsion picture Also die-hard Free Flighter have often dreamed converting countrys millions kids beloved hobby before theyre permanently bewitched video games cousin RC models summer 1986 became responsible developing new toys mass market Director Engineering UN Toys Corporation New York City time $300 million toy manufacturer ET Gotcha Gun fame saw chance fulfill long-held fantasy idea proposed concepts design group marry water reaction motor explained below form jet propulsion five-footwingspan Free Flight model concept looked attractive marketing group ventured predict annual sales volume two three million models Already imagining AMA NFFS memberships soaring Once Id convinced everyone project viable remained design airplane piece cake right Wrong 35 years Free Flight modeling under belt no idea what getting modeler prima donna supposed expert what makes Free Flight model go lets start beginning Propulsion After few trials 22 Model Aviation Ready launch its first successful flight Jammin Jet climbed about 15 seconds transitioned 42 seconds beautiful soaring altitude gain over 100 feet author sprltely-looking waterfueled Free Flight design foamed poly styrene airframe has five-foot wingspan wing area 300 square inches Jammin Jet kit Intended kids innovative design produced 1987-88 UN Toys Corporation Note foamed polystyrene three-piece wing fuselage plastic soda bottle motor/fuel tank air pump nozzle/screw-on valve author shows simple plug-In wing tips foamed polystyrene wing TA L PIVOT S ACE 0 0 E SWIVEL 07 10 DFRGE DOWEL F RUBBER BOLOS RIGHT EV C DC AL SE DE 00 COCA OVER ONE WAY VA ~ WOTOR 00 G AT O OE A- CQULER- ONEWAD OALAESET TO LEAR AR 00 P51 $040 ORIFICE LEO TABEVBVBZiZ ----JAMMIN JETS WATER POWERED MODEL AIRPLANE FASRIC COKE ROTTLE RATED TO RUPOERE AR 100 P51DESIONED WV AR 00900NEW VORAND CAVE AOEIIBELEASED BEFORE LABUCADRAWN BY AL WROBO AGOYT 1987 GATE SW NOD OPEL AT LAUNEB DUE TO WATER PRESSORE BOBBER EAO brainstorming sessions design group narrowed its focus motor/fuel tank thought would work concept simple Wed start 12-oz plastic soda bottle half fill plain old tap water manually pump up other half air remember ordinary bicycle pump 60 psi bottle rated 160 psi rapture pressure screw-on valve designed ensure leakage some rascal try overpressurize bottle corner gas station 60-ft steel cable strung six feet high along lab accept pulley/carriage gizmo soda bottle motor hung bottle pumped up testing began duration distance acceleration weight rate water discharge thrust After some iterative refinements miles videotape decided nozzle diameter 004 data collected indicated jet run 13 16 seconds initial velocity 20 30 feet per second up 20 ounces thrust water jet eruption spectacular toyand drenching So far testing turned up nothing new What conventional reaction motor Water jet momentum exchanged model momentum propelling aircraft forward Time vs thrust curves indicated nonlinear decay expected compressed gas/water mixture released through small orifice aka exhaust pipe initial high burst rapid 10% total motor run decay knee followed longer shallower 60% decay sudden drop zero As well know after 25 years experience flying rubber-powered models time history released energy stored wound rubber can mathematically modeled after perfect gas behavior yet failed detect similarities first blind spot time arrived successful model configuration support new product almost ran out read gets better Configurationairframe design data thrust duration estimated Continued page 75 24 Model Aviation Made 12-az plastic soda bottle motor/fuel tank has 004-in-diameter noz zle screw-on valve ensures leakage case overpressurization fle motorfluel tank halt tilled water soda bottle motor/tank nozzle pumped bicycle pump 160 psi bicycle pump air hose nozzle Above Installing motor four inches forward center-of-gravity setting jet thrust line 1 below CG 22 rd angle achieves nicely controlled climb low water jet efflux still strongly concentrated model begins its climb DE MAR 21Dover DE E KCAM 11th Annual Auction 1200 Noon Regiafration 1000AM lo cated theather wing Blue Hen Mall Rt 13 $100 registration fee & 10% commission formation call Charles Sterner 302878 0618 Sponsor KENT COUNTY AEROMODELERS TX MAR 28Weatherford TX E Aeromodeling Society Swap Meet & Auction 8AM New Larger Local ion Auction 1PM Half Jr High School 902 Charles $5 Admission fee includes door prizes & raffle Free tables 10% Auction Fee Call Sandy Frank 817-S99-7131 info & direc lions Sponsor WEATHERFORD AEROMOD ELING SOCIETY pIOMq ~SWAP MEET & AUCTION f NEW LARGER TION iSaturday Maeeh 28 1992 Hall Jr High School SWAPMEETSaos-Naan r AUCTION Noon-4 pot 902 Charlro StL Weatherfoed Tenao 76086 ALL ACTIVITIES WI THIN THE SAME BUILDING Admission includes 5 Raffle Tickets Adotisaiso 5 Day Unlimited Free Swap Space 10 Auction Fee kCvvvvvvvvv4w WI MAR 28Oshkosh WI E EM Air Adventure Museum 5th Model Airplane Show Modelers Display types airplanes Plastic RIC among museums lull-scale aircraft Share fel lowship see museum displays Admision discount displaying models Contact Carl Swickley 414-428-4800 Sponsor WINNE BAGO RIC FLYERS TIff Aero Modelers ~ March 27 29 1992 ALL RB MODULE WELCOME U CIa.. Tesphla RAPPLE 1 cas d plasm VIDEOS AND PICTURES Infurmailon contact e~ see-sees APRIL Jammin/Donde Continued page 24 weights hand came up design looked attractive flyable Since fueled-up motor/tank weighed nearly 9 oz available initial thrust about 20 oz made 5-ft-wingspan 300-sq-in-wing-area airframe classic Unlimited Rubberstrange eh foamed polystyrene 2-1W/cu-ft density yielded all-up weight 12 14 ounces add structural integrity durability insert-molded Y16-diameter spruce dowels main spars wing fuselage Engine location orientation next task install jet engine ye olde valved soda bottle correct location Thinking problem through gave priority fact motor also fuel tank fuel water will depleted 15 seconds after launch shaving 7 oz off models weight important thing thought keep center-of-gravity stable fuel exhausted since fluctuating CG would affect models trim end situated motor just jettisonable auxiliary tank full-scale jet fighter locatedprecisely under center-of-gravity logical enough reasoning far went problem still overlooking similarities between design Rubber models Failure late July 1987 ad hoc flight test section UN Toy Company headed flying field public park South Hackensack New Jersey test fly aquaplane Cameras ready motor pumped up last check surfaces wind direction launched Nothing ship went out straight almost level gained about 10 feet altitude before jet stream became exhausted nosed down landed Total flight time about 20 seconds did few test flights no better results worst nightmares substantiated toy model dud humbled aura greatness vanished During next two weeks mass produced some 20 models hot-wire-cut sanded videotaped miles disastrous flights hopes stirred now catching thermal stayed work late night watching reflight videotapes slow motion Still nothing meantime wed acquired faithful jeering audience park folks waited daily afternoon flops staged water jet plane will never fly gang early August either succeed tool up mass production million models Christmas season scrap project August 15 happens birthday set drop-dead date Solution Back drawing board reinspected thrust graphs weight data searched equations elusive flaws wing loading too large available thrust simply insufficient thrust Finally light bulb came thrust-time history similar wound rubber torque-time history being case similarity must extend trimming Bingo could h8ve missed Determining models center-of-gravity location three-dimensional problem CG must situated around pitch axis lateral axis balance nose tail also around roll axis longitudinal axis models especially parasol high-wing onesif push pins through tail nose longitudinal axis craft will roll Unlike rubber motor however expends its energy retains its weight water jet motor expends both energy weight reconcile fact conventional approach locating CG solution set motor thrust line below center-of-gravity position motor/fuel tank forward rather CG motor thrust line set below CO model pitches up briefly stalls climb thrust quickly diminishes other hand because motor/fuel tank forward rather coincident CG model becomes nose-heavy wants dive both nose-up moment nose-down moment present As fuel water depleted nose lightens nose-down moment decreases since thrust also decays nose-up moment lessens well could match rates decay two moments make nose-up moments decline lag behind nose-down moments tad nicely controlled net climb would result took long discover Im sure Perhaps overzealousness about projects potential made little light-headed After performing some calculations matching graphs moved motor/fuel tank four inches forward CG set jet thrust line 1 below CG 228 upward angle Success last faithful afternoon crowd Vice President Sales hand out give last heave launched ship climbed 15 secondspostflight videotapes showed altitude gain over 100 feetand genfly transitioned 42 seconds beautiful soaring couldnt have better birthday present Continued page 85 February 1992 75 6TH ANNUAL WESTERN FLYERS RIO AUCTION 4/5/82 IN SPRINGFIELD NERS NEAR OMAHA OVER 122000 TO BE SOLDI $1000 RAFFLE LARGEST AUCTION IN MID WESTIIIII FOR INFO BOB BOUMSTEIN BSU S 165TH AVE OMAHA NE 68130 Over next few weeks company manufactured nearly 50 models christened Jammin Jets Madison Avenue advertising agency engineer technician salesman out learning fly Some novice fliers achieved durations half minutes benefit thermals improve power phase emulated delayed prop release Wakefield modifying valve water jet does start until model has launched way stored energy fully utilized Production next step tooling Since foam molding done cast aluminum cavities molds wood pattern must first fabricated surprise master patternmakers Massachusetts-based pattern shop assigned work turned out old-time modeler nice break since no problems communicating technical happy ending Concurrenfly tooling other preparation mass production another dose fun came way company agreed back sales effort childrens prime-time TV ad campaign job produce 30-second commercial same New York advertising agency dreamed up models name selected compose jingle score prepare story line Hollywood company filmed commercial location Osmond Brothers studios Provo Utah engineering group supplied models production technical support built test flew 50 models enlisted Scott Croizier Cleveland Ohio build two electrically powered RC airplanes Jammin Jet silhouette intended flybys remote filming end RC models used lot fun flying child actors no idea launch Free Flight model trained spot Most caught within hour became engrossed impromptu contests arranged filming yielded 18000 feet celluloid 3000 feet selected Accompanied captivating theme song High Can Fly 30-second commercial showed bunch kids rising sun backs flying Jammin Jet against Utah mountain horizon beautiful spectacularand successful million half models shipped next year Free Flight forever article dedicated late good friend Scott Croizier Free Flight modeler well family man professional pilot brave spirit Scott left us last yearE Flying Fun/Mathews Continued page 31 leading edge above trailing edge datum line drawn other words Clark Y section would call flat bottomed very Continued page 86 PLUG IN WINGS / ADVANCED FULL SYMETRICAL AIRFOIL / RATED FOR ALL MANEUVERS INCLUDING MAXIMUM G PULL UPS / CLEAN AERODYNAMIC DESIGN IS FAST STABLE AND EFFICIENT TM z 2 0 0 0 C 4 4 0 n Wingspan 47Area 460 sq 2 Assembly Time 6 hrs mas Lenght 42Weight 475-500 lb PRE-ASSEMBLED AND INSTALLED HAYES MOUNT NOSEGEAN 8 OZ HAYES TANK SULUVAN SKYLITE WHEELS SULLIVAN PUSHROOS CONTROL HORNS GAPLESS HINGES ALL AROUND February 1992 85 nomenclatureairfoil washout angle Jammin/Dondeincidence etc Continued page 75 COMPLETELY ASSEMBLED & FINISHED OUT OF THE BOX NO GLUE PAINT OR COVERING REQUIRED INSTALL YOUR RADIO 35-46 ENGINE AND PROP AT THE FIELD COMPUTER DESIGNED & BUILT BY MIT AEROSPACE ENGINEERS INCREDIBLE FLIGHT PERFORMANCE AND QUALITY BUILT-IN Hi-G introduces theMhUIIISUhUiI 0 VISA & MC Accepted Orders & Info 602-788-5209 H -G 2131 E Crocus Dr Phoenix AZ 85022
Edition: Model Aviation - 1992/02
Page Numbers: 22, 23, 24, 75, 85
ELI WLYJ2LiWEIDJ Ever see water jet streaming out Free Flight model author took new product development New Yorkbased toy manufacturer chance go high profile something daring fun HAnk Donde WATER-POWERED aircraft thought Model airplanes already powered fire internal combustion earth rubber Isnt time bring aqua stuff propulsion picture Also die-hard Free Flighter have often dreamed converting countrys millions kids beloved hobby before theyre permanently bewitched video games cousin RC models summer 1986 became responsible developing new toys mass market Director Engineering UN Toys Corporation New York City time $300 million toy manufacturer ET Gotcha Gun fame saw chance fulfill long-held fantasy idea proposed concepts design group marry water reaction motor explained below form jet propulsion five-footwingspan Free Flight model concept looked attractive marketing group ventured predict annual sales volume two three million models Already imagining AMA NFFS memberships soaring Once Id convinced everyone project viable remained design airplane piece cake right Wrong 35 years Free Flight modeling under belt no idea what getting modeler prima donna supposed expert what makes Free Flight model go lets start beginning Propulsion After few trials 22 Model Aviation Ready launch its first successful flight Jammin Jet climbed about 15 seconds transitioned 42 seconds beautiful soaring altitude gain over 100 feet author sprltely-looking waterfueled Free Flight design foamed poly styrene airframe has five-foot wingspan wing area 300 square inches Jammin Jet kit Intended kids innovative design produced 1987-88 UN Toys Corporation Note foamed polystyrene three-piece wing fuselage plastic soda bottle motor/fuel tank air pump nozzle/screw-on valve author shows simple plug-In wing tips foamed polystyrene wing TA L PIVOT S ACE 0 0 E SWIVEL 07 10 DFRGE DOWEL F RUBBER BOLOS RIGHT EV C DC AL SE DE 00 COCA OVER ONE WAY VA ~ WOTOR 00 G AT O OE A- CQULER- ONEWAD OALAESET TO LEAR AR 00 P51 $040 ORIFICE LEO TABEVBVBZiZ ----JAMMIN JETS WATER POWERED MODEL AIRPLANE FASRIC COKE ROTTLE RATED TO RUPOERE AR 100 P51DESIONED WV AR 00900NEW VORAND CAVE AOEIIBELEASED BEFORE LABUCADRAWN BY AL WROBO AGOYT 1987 GATE SW NOD OPEL AT LAUNEB DUE TO WATER PRESSORE BOBBER EAO brainstorming sessions design group narrowed its focus motor/fuel tank thought would work concept simple Wed start 12-oz plastic soda bottle half fill plain old tap water manually pump up other half air remember ordinary bicycle pump 60 psi bottle rated 160 psi rapture pressure screw-on valve designed ensure leakage some rascal try overpressurize bottle corner gas station 60-ft steel cable strung six feet high along lab accept pulley/carriage gizmo soda bottle motor hung bottle pumped up testing began duration distance acceleration weight rate water discharge thrust After some iterative refinements miles videotape decided nozzle diameter 004 data collected indicated jet run 13 16 seconds initial velocity 20 30 feet per second up 20 ounces thrust water jet eruption spectacular toyand drenching So far testing turned up nothing new What conventional reaction motor Water jet momentum exchanged model momentum propelling aircraft forward Time vs thrust curves indicated nonlinear decay expected compressed gas/water mixture released through small orifice aka exhaust pipe initial high burst rapid 10% total motor run decay knee followed longer shallower 60% decay sudden drop zero As well know after 25 years experience flying rubber-powered models time history released energy stored wound rubber can mathematically modeled after perfect gas behavior yet failed detect similarities first blind spot time arrived successful model configuration support new product almost ran out read gets better Configurationairframe design data thrust duration estimated Continued page 75 24 Model Aviation Made 12-az plastic soda bottle motor/fuel tank has 004-in-diameter noz zle screw-on valve ensures leakage case overpressurization fle motorfluel tank halt tilled water soda bottle motor/tank nozzle pumped bicycle pump 160 psi bicycle pump air hose nozzle Above Installing motor four inches forward center-of-gravity setting jet thrust line 1 below CG 22 rd angle achieves nicely controlled climb low water jet efflux still strongly concentrated model begins its climb DE MAR 21Dover DE E KCAM 11th Annual Auction 1200 Noon Regiafration 1000AM lo cated theather wing Blue Hen Mall Rt 13 $100 registration fee & 10% commission formation call Charles Sterner 302878 0618 Sponsor KENT COUNTY AEROMODELERS TX MAR 28Weatherford TX E Aeromodeling Society Swap Meet & Auction 8AM New Larger Local ion Auction 1PM Half Jr High School 902 Charles $5 Admission fee includes door prizes & raffle Free tables 10% Auction Fee Call Sandy Frank 817-S99-7131 info & direc lions Sponsor WEATHERFORD AEROMOD ELING SOCIETY pIOMq ~SWAP MEET & AUCTION f NEW LARGER TION iSaturday Maeeh 28 1992 Hall Jr High School SWAPMEETSaos-Naan r AUCTION Noon-4 pot 902 Charlro StL Weatherfoed Tenao 76086 ALL ACTIVITIES WI THIN THE SAME BUILDING Admission includes 5 Raffle Tickets Adotisaiso 5 Day Unlimited Free Swap Space 10 Auction Fee kCvvvvvvvvv4w WI MAR 28Oshkosh WI E EM Air Adventure Museum 5th Model Airplane Show Modelers Display types airplanes Plastic RIC among museums lull-scale aircraft Share fel lowship see museum displays Admision discount displaying models Contact Carl Swickley 414-428-4800 Sponsor WINNE BAGO RIC FLYERS TIff Aero Modelers ~ March 27 29 1992 ALL RB MODULE WELCOME U CIa.. Tesphla RAPPLE 1 cas d plasm VIDEOS AND PICTURES Infurmailon contact e~ see-sees APRIL Jammin/Donde Continued page 24 weights hand came up design looked attractive flyable Since fueled-up motor/tank weighed nearly 9 oz available initial thrust about 20 oz made 5-ft-wingspan 300-sq-in-wing-area airframe classic Unlimited Rubberstrange eh foamed polystyrene 2-1W/cu-ft density yielded all-up weight 12 14 ounces add structural integrity durability insert-molded Y16-diameter spruce dowels main spars wing fuselage Engine location orientation next task install jet engine ye olde valved soda bottle correct location Thinking problem through gave priority fact motor also fuel tank fuel water will depleted 15 seconds after launch shaving 7 oz off models weight important thing thought keep center-of-gravity stable fuel exhausted since fluctuating CG would affect models trim end situated motor just jettisonable auxiliary tank full-scale jet fighter locatedprecisely under center-of-gravity logical enough reasoning far went problem still overlooking similarities between design Rubber models Failure late July 1987 ad hoc flight test section UN Toy Company headed flying field public park South Hackensack New Jersey test fly aquaplane Cameras ready motor pumped up last check surfaces wind direction launched Nothing ship went out straight almost level gained about 10 feet altitude before jet stream became exhausted nosed down landed Total flight time about 20 seconds did few test flights no better results worst nightmares substantiated toy model dud humbled aura greatness vanished During next two weeks mass produced some 20 models hot-wire-cut sanded videotaped miles disastrous flights hopes stirred now catching thermal stayed work late night watching reflight videotapes slow motion Still nothing meantime wed acquired faithful jeering audience park folks waited daily afternoon flops staged water jet plane will never fly gang early August either succeed tool up mass production million models Christmas season scrap project August 15 happens birthday set drop-dead date Solution Back drawing board reinspected thrust graphs weight data searched equations elusive flaws wing loading too large available thrust simply insufficient thrust Finally light bulb came thrust-time history similar wound rubber torque-time history being case similarity must extend trimming Bingo could h8ve missed Determining models center-of-gravity location three-dimensional problem CG must situated around pitch axis lateral axis balance nose tail also around roll axis longitudinal axis models especially parasol high-wing onesif push pins through tail nose longitudinal axis craft will roll Unlike rubber motor however expends its energy retains its weight water jet motor expends both energy weight reconcile fact conventional approach locating CG solution set motor thrust line below center-of-gravity position motor/fuel tank forward rather CG motor thrust line set below CO model pitches up briefly stalls climb thrust quickly diminishes other hand because motor/fuel tank forward rather coincident CG model becomes nose-heavy wants dive both nose-up moment nose-down moment present As fuel water depleted nose lightens nose-down moment decreases since thrust also decays nose-up moment lessens well could match rates decay two moments make nose-up moments decline lag behind nose-down moments tad nicely controlled net climb would result took long discover Im sure Perhaps overzealousness about projects potential made little light-headed After performing some calculations matching graphs moved motor/fuel tank four inches forward CG set jet thrust line 1 below CG 228 upward angle Success last faithful afternoon crowd Vice President Sales hand out give last heave launched ship climbed 15 secondspostflight videotapes showed altitude gain over 100 feetand genfly transitioned 42 seconds beautiful soaring couldnt have better birthday present Continued page 85 February 1992 75 6TH ANNUAL WESTERN FLYERS RIO AUCTION 4/5/82 IN SPRINGFIELD NERS NEAR OMAHA OVER 122000 TO BE SOLDI $1000 RAFFLE LARGEST AUCTION IN MID WESTIIIII FOR INFO BOB BOUMSTEIN BSU S 165TH AVE OMAHA NE 68130 Over next few weeks company manufactured nearly 50 models christened Jammin Jets Madison Avenue advertising agency engineer technician salesman out learning fly Some novice fliers achieved durations half minutes benefit thermals improve power phase emulated delayed prop release Wakefield modifying valve water jet does start until model has launched way stored energy fully utilized Production next step tooling Since foam molding done cast aluminum cavities molds wood pattern must first fabricated surprise master patternmakers Massachusetts-based pattern shop assigned work turned out old-time modeler nice break since no problems communicating technical happy ending Concurrenfly tooling other preparation mass production another dose fun came way company agreed back sales effort childrens prime-time TV ad campaign job produce 30-second commercial same New York advertising agency dreamed up models name selected compose jingle score prepare story line Hollywood company filmed commercial location Osmond Brothers studios Provo Utah engineering group supplied models production technical support built test flew 50 models enlisted Scott Croizier Cleveland Ohio build two electrically powered RC airplanes Jammin Jet silhouette intended flybys remote filming end RC models used lot fun flying child actors no idea launch Free Flight model trained spot Most caught within hour became engrossed impromptu contests arranged filming yielded 18000 feet celluloid 3000 feet selected Accompanied captivating theme song High Can Fly 30-second commercial showed bunch kids rising sun backs flying Jammin Jet against Utah mountain horizon beautiful spectacularand successful million half models shipped next year Free Flight forever article dedicated late good friend Scott Croizier Free Flight modeler well family man professional pilot brave spirit Scott left us last yearE Flying Fun/Mathews Continued page 31 leading edge above trailing edge datum line drawn other words Clark Y section would call flat bottomed very Continued page 86 PLUG IN WINGS / ADVANCED FULL SYMETRICAL AIRFOIL / RATED FOR ALL MANEUVERS INCLUDING MAXIMUM G PULL UPS / CLEAN AERODYNAMIC DESIGN IS FAST STABLE AND EFFICIENT TM z 2 0 0 0 C 4 4 0 n Wingspan 47Area 460 sq 2 Assembly Time 6 hrs mas Lenght 42Weight 475-500 lb PRE-ASSEMBLED AND INSTALLED HAYES MOUNT NOSEGEAN 8 OZ HAYES TANK SULUVAN SKYLITE WHEELS SULLIVAN PUSHROOS CONTROL HORNS GAPLESS HINGES ALL AROUND February 1992 85 nomenclatureairfoil washout angle Jammin/Dondeincidence etc Continued page 75 COMPLETELY ASSEMBLED & FINISHED OUT OF THE BOX NO GLUE PAINT OR COVERING REQUIRED INSTALL YOUR RADIO 35-46 ENGINE AND PROP AT THE FIELD COMPUTER DESIGNED & BUILT BY MIT AEROSPACE ENGINEERS INCREDIBLE FLIGHT PERFORMANCE AND QUALITY BUILT-IN Hi-G introduces theMhUIIISUhUiI 0 VISA & MC Accepted Orders & Info 602-788-5209 H -G 2131 E Crocus Dr Phoenix AZ 85022