AA ior ventuz between EA AMA d45kidsb fas mating wor ~ m-ize home l airplanes L would like tr am like th area tion help u EBob Underwoo WHAT HAS FLIP slip 90 eyes its EAA Air Academy Weekend course problem answer prompts another question What Air Academy Weekend Perhaps next gaggle paragraphs will able bring activity focus years both modelers fullscalers have concerned about fact ranks AMA EAA have steadily increased number young people involved has kept pace Under leadership Experimental Aircraft Association education director Charles Larsen youth program has launched incorporates both full-scale modeling activity first pilot pro gram series four held Freder ick MD January 30-31 1988 AMA Friday evening January 29th some 45 volunteers interested parties gath ered classroom Aviation School Frederick Community College located Frederick Airport Chuck Larsen led meeting explained various parts program responsibilities involved video greeting featuring EAA officials Paul Tom Poberenzy stated reasons goals program During course evening Chuck asked person stand share some information about himself/herself proved interesting since con firmed thought shared Mr Larsen author two years ago person did identif himself either EAA AMA member could determine organization belonged solely background Indeed pre dicted some 15% attendance members both organizations Yes EAA AMA have much common Individuals move back forth between organizations interests change Sometimes full-scaler wants test ideas model form loses ticket health reasons takes up model ing other hand modelers accept challenge going aloft own crea tions turn EAA Other persons sharing stage eve ning Lance Zellers coordinated enrollments housing major de tails Phil Woodruff education director FAA representatives aviation insurers Avemco July 1988 77 Top Air Academy participants constructed full-size ribs home-built airplane hands-on projects during weekend Above Several lull-scale airplanes flown two-day event Jerry Blake aviation school administrator points out strut details Part three-hour modeling session contained some hangar talk about types mod els building techniques 45 flying buffs divided groups about 15 Saturday morning brought flurry ac tivity 45 young people ages 13 18 found way hangar di vided groups age assigned three activity sessions Air Academy Weekend under way should say wing session lasted three hours allowed ample time lec ture presentation actual building pe riod session led Chuck Larsen basically Mr Wizard type pro gram Through use kites hot air bal loons simple gliders presented history theory flight Plastic bags floated toward hangar roof kites wafted cool Maryland air gliders appropriate trim tabs circled classroom items ultimately faced aviation reality however landed second session led two BAA home-builders featured construction two full-scale parts full-sized wing rib built using truss construction Wood strips gussets glue nails combined make rib take shape second item young people made skid/slip indi cator found necessary AMAIEAA member Tom Crone explains sand wingtip Toms wife Krls also hand entire weekend help out cut file bend metal Combined wasa curved piece tubing glycerin BR screws pen used cali brate device third part activity sessions devoted modeling privileged lead program very ably sisted cadre AMA BAA mem bers started using 13-minute video produced National Geographic during 1986 Nats Lake Charles film speaks nonmodelers presents rather complete overview modeling disciplines includes everything door Formula 1 j Model Aviation Cresser helps outone c - pesky dihedral breaks CyA glues helped speed things up everyone got lesson much sawdust 15 people can make uuring break between sessions au thor launches Indoor Rubber Scale model borrowed Don Srull occasion ities between modeling full-scale avia tion followed film various forms model flying presented using Con trol Line Indoor Rubber Scale flew hangar Radio Control Watch future events areal Better yet model club EAA chapter would like participate contact AMA Technical Di rector Bob Underwood AMA Headquarters unit techniques explained new materials shown volunteers provided wide range models including some framed-up stage participant constructed Mid west Flip Hand-Launched Glider Thanks using cyanoacrylate CyA glues pro vided Carl Goldberg Models planes went together hour found 15 persons sanding once classroom can produce lot dust Once finished checked proper CG center-of gravity test glided hangar tossed skyward ramp front Inter estingly difficult get young folks throw hard experi enced satisfactory flight however also flew AMA Cub Delta Dart built helpers dur Continued page 159 July 1988 79 EAA Education Director Chuck Larsen sists Intense student launching hot-air balloon part Mr Wizard session history theory aviation John Patton former AMA president checks see center gravity CG came out right place before test flying Flip Hand-Launched Glider Midwest donated models Can stage anynvwvng teennui nyThe modest registra tion fee inciuaea aii ihe materials bui nree meals during two-day program CL Speed/Hempel Continued page 69 Automotive Devices CAD Indiana Curtis hired Paul Frank Aeromarine/Shev uns chief engineer aid transfer mate rial technology Bedford located southcentral Indiana eight Shevlin people Paul asked accompany him three us did CAD Dyna-Fog Dyna-Jet re turned production after long delay re search begun smaller versions both Ad ditionally pulsejet-powered steam generator being considered drafting department expanded hiring man working engineering degree also familiar Dyna-Jet having won Jet Speed events previous subsequent years refer James Richmond currently very ac tive successful national international Indoor FF competition year-and-a-half after move Bedford Paul Frank remained others us hav ing left various reasons Prototype small Dyna-Fog machines fabricated refinement begun preparation quantity pro duction However other research pulsejet projects halted including smaller Dyna-Jet Several years later ironically modestly successful Japanese-made Tigeriet placed sale country few years later Curtis moved company Westfield located just north Indianapolis changed company name Curtis Dyna Products Presumably acknowledge ment renewed importance company creations ideas Aeromarine Shevlin remains named today although Mr Curtis passed away few years ago am unaware current products projects Curtis Dyna-Products know extensive changes Dyna-Fog series Only Dyna-Jet same years ago probable improved technoques have adopted some production steps far can learn item Dyna-Jet ever pro duced interchangeable its counterpart other Indeed parts its foreign clones least three also fully interchangeableeven use US stan dard threads metricized country after 40 years almost continuous production days successful competitors Jet Speed extensively modify engines Among other things concoct fuel blends make bigger bang does gasoline ap plication seems safe say however manufactured properly used Dyna-Jet re mains easiest-starting consistent performance reliable safest eeonomical operate minlature power plant ever placed production Once again want thank Gerald L Jerry Wiles sharing fascinating bit personal history us love cards letters photos send Weekend/Underwood Continued page 79 ing talking presentation Along taxied wingless RC modelwe too close active runway fly Parked airplanes snow prevented us flying Control Line well Something very significant occurred break after sessions young people models hand gravitated AMA room studied mod els display importantly repaired modified model built Flip became Stealth-type air craft through ingenious use scrap balsa conclusion model session participant given goody bun dle containing AMA material copy Model Aviaf ion AMA Cub build home program covered 10 hours Satur day lunch dinner served hangar airport restaurant Saturday eve ning featured wind-up session films brief comments Sunday third session held morning noon lunch shared participants parents volunteers Hangar talk abounded everyone opportunity look over several full-scale aircraft flown day three afternoon everyone headed home savoring experi ences first Air Academy Weekend clean-up session helpers fol lowed pleasant dinner local restaur ant table talk bubbled suc cess weekends event person whether EAAer AMAer said next program occurred area wanted part seeond four pilot programs held Minneapolis-St Paul area end February modeling ses sion being led Boyd Bowdish District VII assistant vice-president Two will held Tulsa OK Indianapolis IN later year What come Plans under way within EAA expand program AMA pleased have opportunity participate effort utilize talents MIhIJET SERIESThe Proud Bird theProud Bird planes feature balsadesIgned meet constructIon Designed ith the0lPR5 Formula intermediate flyer mind ,ill 120 ralesThls 1/i arcept 21 25 size engineCase ,tTZJscale model hill accept o reur eahaust engine em 60120 ci size engines ceptiseul perfuraanceDet al l~uo5o.Epoap glass faselagewlth t5rill jet elthou t foam wIng constructIon Full kIt $15000 toe hassles darted fan SoyhamiSemIkIt also avaIlaBle Ino mood $12511 Special Introductory PrIce Please add $1000 shIppIng handling sillS plus $300 IBM flu hes Send check Md add dl sales too Mastercard PIsa SOOLE MametS coo add $200 t3BSSBIM477 PARRISH AIRCRAFT fop Turkey formula 1 dDart EaperimentalI2ssW491hre, ISSOD dhTigersharktwoplace full sIze aIrcraftPInIatiaeFj 3331 July 1988 159 both EAA chapters AMA charter clubs exchanging list ings club chapter would like participate activities directed toward youth contact Bob Under wood AMA Technical Director 1810 Sam uel Morse Dr Reston VA 22090 terrific experience About Noise/Lowe Continued page 91 engine does mean anti Electrics great low-energy ap plications Still will never match energy-per-pound ratio piston en gine simply because no known bat tery energy density alcohol gasoline fuel Some years ago involved de velopment RPV using ad vanced lithium hydride very dangerous battery system concert ad vanced motor design around cobalt turned prop same rpm com parable piston engine found RPV system approximately noisy piston engine setup addition RPV netted about 25% energy density piston engine gasoline setup other words Electric system 300 watt hours per pound would operate just 25% duration piston en gine equivalent weight Furthermore Ni-Cd batteries used models have far less energy high-performance lithium hydride batteries tested Four-stroke engines usually credited being quieter two-stroke ones testing has contradicted assumption given rpm primary sound frequency typical four-stroke engine half two-stroke may fact sound pleasant measured dB levels prove comparable fact some Pat tern fliers have shied away four-stroke engines because too noisy Remem ber dB meter scale does compen sate perceived sound lowering its re sponse lower frequencies since tries simulate human response Most four-stroke Pattern fliers using high prop pitch 1112 less diameter reduce rpm noise Four-strokers have mechanical noise addition suspect generate airframe noise due higher vibration Check out prop diameter rpm tip velocity typical four-stroke engine Youll find higher typical two-stroke F3A Pattern ship setup What modeling world needs greater availability high-quality stiff high-pitch props Various measures can taken reduce engine mechanical noisesthose radiated propulsion system surfaces such bearings etcas well sound radiation walls engine muffler pipe forth lack well-quantified data area have seen 2-dR noise re duction replacing noisy bearings new ones 1- 2-dB drop using rub ber sleeve tuned pipe 1-dB reduc tion using filter intake pri mary focus quest sound reduc tion should course having quality muffler getting propeller tip speed down ancillary modifications should also considered Airframe noise generated thrash ing single-cylinder model engine design cannot perfectly balanced again well quantified certainly proven source noise some models inherent resistance perfect balance such engines due nonlinear accelera tion forces piston offset connecting rod function rotation addition have torsional vibration created impulsive nature beasta phenomenon makes Perry vibrator fuel pump work well several ways alleviate problem First could go multiple cyl inders However very practical solution would still have torsional vibration although its frequency would crease function number firings per revolution Second could enclose engine exhaust system inside airframean effective strategy far goes still capable eliminating tor sional vibration Third could change well-balanced electric motor Electrics usually operate very smoothly Interest ingly too impulsive systems thus likewise exhibit torsional vibration higher frequency function number poles motor As mat ter fact knowledge everything life impulsive cyclic nature amazing think about far satisfactory solution air frame noise shield engine vibration airframe through use rubber metal isolators Several Pattern fliers have experimenting rubber en gine mounts various kinds have found case noise reduced Secondary perhaps primary bene fits isolation saving radio system failure eliminating incidence fuel foaming has struck down flier Also may prevent breakage loosening pushrod fittings engine mounts RPV project employed vibration isolation engine conse quently experienced no instance elec tronic failure due vibration Certainly worth price effort Isolating engine also removes very high-peak im pulsive loads engine permits much lighter less robust engine mount system Some will argue theyve tried Lord mounts found system wouldnt stay together response setup properly designed First mount systems natural frequency must outside operating frequency range engine harmonics can tear apart usually means very low soft frequency system Second peak loads iso lators must rupture rubber/metal bonds its important choose cor rect isolator task highly em pirical design solution cut try typ ical 60 engine installation uses three four liz- 9A6-in-diameter Lord mounts supporting engine radial mount fashion addition exhaust system pipe must rubber isolated also experiments quiet mufflers have found presence airframe noise testing engine mounted airplane versus testing engine mount significantly lessens noise reduc tion induced muffler air160 Model Aviation THERMAL CHARGER what looking electric sailplane good looks easy build fun fly great perfor mance Thermal Charger fl PRECISION PRODUCTS INC 714 592-5144 510 E Arrow Highway San Dimas CA 91773
Edition: Model Aviation - 1988/07
Page Numbers: 77, 78, 79, 159, 160
AA ior ventuz between EA AMA d45kidsb fas mating wor ~ m-ize home l airplanes L would like tr am like th area tion help u EBob Underwoo WHAT HAS FLIP slip 90 eyes its EAA Air Academy Weekend course problem answer prompts another question What Air Academy Weekend Perhaps next gaggle paragraphs will able bring activity focus years both modelers fullscalers have concerned about fact ranks AMA EAA have steadily increased number young people involved has kept pace Under leadership Experimental Aircraft Association education director Charles Larsen youth program has launched incorporates both full-scale modeling activity first pilot pro gram series four held Freder ick MD January 30-31 1988 AMA Friday evening January 29th some 45 volunteers interested parties gath ered classroom Aviation School Frederick Community College located Frederick Airport Chuck Larsen led meeting explained various parts program responsibilities involved video greeting featuring EAA officials Paul Tom Poberenzy stated reasons goals program During course evening Chuck asked person stand share some information about himself/herself proved interesting since con firmed thought shared Mr Larsen author two years ago person did identif himself either EAA AMA member could determine organization belonged solely background Indeed pre dicted some 15% attendance members both organizations Yes EAA AMA have much common Individuals move back forth between organizations interests change Sometimes full-scaler wants test ideas model form loses ticket health reasons takes up model ing other hand modelers accept challenge going aloft own crea tions turn EAA Other persons sharing stage eve ning Lance Zellers coordinated enrollments housing major de tails Phil Woodruff education director FAA representatives aviation insurers Avemco July 1988 77 Top Air Academy participants constructed full-size ribs home-built airplane hands-on projects during weekend Above Several lull-scale airplanes flown two-day event Jerry Blake aviation school administrator points out strut details Part three-hour modeling session contained some hangar talk about types mod els building techniques 45 flying buffs divided groups about 15 Saturday morning brought flurry ac tivity 45 young people ages 13 18 found way hangar di vided groups age assigned three activity sessions Air Academy Weekend under way should say wing session lasted three hours allowed ample time lec ture presentation actual building pe riod session led Chuck Larsen basically Mr Wizard type pro gram Through use kites hot air bal loons simple gliders presented history theory flight Plastic bags floated toward hangar roof kites wafted cool Maryland air gliders appropriate trim tabs circled classroom items ultimately faced aviation reality however landed second session led two BAA home-builders featured construction two full-scale parts full-sized wing rib built using truss construction Wood strips gussets glue nails combined make rib take shape second item young people made skid/slip indi cator found necessary AMAIEAA member Tom Crone explains sand wingtip Toms wife Krls also hand entire weekend help out cut file bend metal Combined wasa curved piece tubing glycerin BR screws pen used cali brate device third part activity sessions devoted modeling privileged lead program very ably sisted cadre AMA BAA mem bers started using 13-minute video produced National Geographic during 1986 Nats Lake Charles film speaks nonmodelers presents rather complete overview modeling disciplines includes everything door Formula 1 j Model Aviation Cresser helps outone c - pesky dihedral breaks CyA glues helped speed things up everyone got lesson much sawdust 15 people can make uuring break between sessions au thor launches Indoor Rubber Scale model borrowed Don Srull occasion ities between modeling full-scale avia tion followed film various forms model flying presented using Con trol Line Indoor Rubber Scale flew hangar Radio Control Watch future events areal Better yet model club EAA chapter would like participate contact AMA Technical Di rector Bob Underwood AMA Headquarters unit techniques explained new materials shown volunteers provided wide range models including some framed-up stage participant constructed Mid west Flip Hand-Launched Glider Thanks using cyanoacrylate CyA glues pro vided Carl Goldberg Models planes went together hour found 15 persons sanding once classroom can produce lot dust Once finished checked proper CG center-of gravity test glided hangar tossed skyward ramp front Inter estingly difficult get young folks throw hard experi enced satisfactory flight however also flew AMA Cub Delta Dart built helpers dur Continued page 159 July 1988 79 EAA Education Director Chuck Larsen sists Intense student launching hot-air balloon part Mr Wizard session history theory aviation John Patton former AMA president checks see center gravity CG came out right place before test flying Flip Hand-Launched Glider Midwest donated models Can stage anynvwvng teennui nyThe modest registra tion fee inciuaea aii ihe materials bui nree meals during two-day program CL Speed/Hempel Continued page 69 Automotive Devices CAD Indiana Curtis hired Paul Frank Aeromarine/Shev uns chief engineer aid transfer mate rial technology Bedford located southcentral Indiana eight Shevlin people Paul asked accompany him three us did CAD Dyna-Fog Dyna-Jet re turned production after long delay re search begun smaller versions both Ad ditionally pulsejet-powered steam generator being considered drafting department expanded hiring man working engineering degree also familiar Dyna-Jet having won Jet Speed events previous subsequent years refer James Richmond currently very ac tive successful national international Indoor FF competition year-and-a-half after move Bedford Paul Frank remained others us hav ing left various reasons Prototype small Dyna-Fog machines fabricated refinement begun preparation quantity pro duction However other research pulsejet projects halted including smaller Dyna-Jet Several years later ironically modestly successful Japanese-made Tigeriet placed sale country few years later Curtis moved company Westfield located just north Indianapolis changed company name Curtis Dyna Products Presumably acknowledge ment renewed importance company creations ideas Aeromarine Shevlin remains named today although Mr Curtis passed away few years ago am unaware current products projects Curtis Dyna-Products know extensive changes Dyna-Fog series Only Dyna-Jet same years ago probable improved technoques have adopted some production steps far can learn item Dyna-Jet ever pro duced interchangeable its counterpart other Indeed parts its foreign clones least three also fully interchangeableeven use US stan dard threads metricized country after 40 years almost continuous production days successful competitors Jet Speed extensively modify engines Among other things concoct fuel blends make bigger bang does gasoline ap plication seems safe say however manufactured properly used Dyna-Jet re mains easiest-starting consistent performance reliable safest eeonomical operate minlature power plant ever placed production Once again want thank Gerald L Jerry Wiles sharing fascinating bit personal history us love cards letters photos send Weekend/Underwood Continued page 79 ing talking presentation Along taxied wingless RC modelwe too close active runway fly Parked airplanes snow prevented us flying Control Line well Something very significant occurred break after sessions young people models hand gravitated AMA room studied mod els display importantly repaired modified model built Flip became Stealth-type air craft through ingenious use scrap balsa conclusion model session participant given goody bun dle containing AMA material copy Model Aviaf ion AMA Cub build home program covered 10 hours Satur day lunch dinner served hangar airport restaurant Saturday eve ning featured wind-up session films brief comments Sunday third session held morning noon lunch shared participants parents volunteers Hangar talk abounded everyone opportunity look over several full-scale aircraft flown day three afternoon everyone headed home savoring experi ences first Air Academy Weekend clean-up session helpers fol lowed pleasant dinner local restaur ant table talk bubbled suc cess weekends event person whether EAAer AMAer said next program occurred area wanted part seeond four pilot programs held Minneapolis-St Paul area end February modeling ses sion being led Boyd Bowdish District VII assistant vice-president Two will held Tulsa OK Indianapolis IN later year What come Plans under way within EAA expand program AMA pleased have opportunity participate effort utilize talents MIhIJET SERIESThe Proud Bird theProud Bird planes feature balsadesIgned meet constructIon Designed ith the0lPR5 Formula intermediate flyer mind ,ill 120 ralesThls 1/i arcept 21 25 size engineCase ,tTZJscale model hill accept o reur eahaust engine em 60120 ci size engines ceptiseul perfuraanceDet al l~uo5o.Epoap glass faselagewlth t5rill jet elthou t foam wIng constructIon Full kIt $15000 toe hassles darted fan SoyhamiSemIkIt also avaIlaBle Ino mood $12511 Special Introductory PrIce Please add $1000 shIppIng handling sillS plus $300 IBM flu hes Send check Md add dl sales too Mastercard PIsa SOOLE MametS coo add $200 t3BSSBIM477 PARRISH AIRCRAFT fop Turkey formula 1 dDart EaperimentalI2ssW491hre, ISSOD dhTigersharktwoplace full sIze aIrcraftPInIatiaeFj 3331 July 1988 159 both EAA chapters AMA charter clubs exchanging list ings club chapter would like participate activities directed toward youth contact Bob Under wood AMA Technical Director 1810 Sam uel Morse Dr Reston VA 22090 terrific experience About Noise/Lowe Continued page 91 engine does mean anti Electrics great low-energy ap plications Still will never match energy-per-pound ratio piston en gine simply because no known bat tery energy density alcohol gasoline fuel Some years ago involved de velopment RPV using ad vanced lithium hydride very dangerous battery system concert ad vanced motor design around cobalt turned prop same rpm com parable piston engine found RPV system approximately noisy piston engine setup addition RPV netted about 25% energy density piston engine gasoline setup other words Electric system 300 watt hours per pound would operate just 25% duration piston en gine equivalent weight Furthermore Ni-Cd batteries used models have far less energy high-performance lithium hydride batteries tested Four-stroke engines usually credited being quieter two-stroke ones testing has contradicted assumption given rpm primary sound frequency typical four-stroke engine half two-stroke may fact sound pleasant measured dB levels prove comparable fact some Pat tern fliers have shied away four-stroke engines because too noisy Remem ber dB meter scale does compen sate perceived sound lowering its re sponse lower frequencies since tries simulate human response Most four-stroke Pattern fliers using high prop pitch 1112 less diameter reduce rpm noise Four-strokers have mechanical noise addition suspect generate airframe noise due higher vibration Check out prop diameter rpm tip velocity typical four-stroke engine Youll find higher typical two-stroke F3A Pattern ship setup What modeling world needs greater availability high-quality stiff high-pitch props Various measures can taken reduce engine mechanical noisesthose radiated propulsion system surfaces such bearings etcas well sound radiation walls engine muffler pipe forth lack well-quantified data area have seen 2-dR noise re duction replacing noisy bearings new ones 1- 2-dB drop using rub ber sleeve tuned pipe 1-dB reduc tion using filter intake pri mary focus quest sound reduc tion should course having quality muffler getting propeller tip speed down ancillary modifications should also considered Airframe noise generated thrash ing single-cylinder model engine design cannot perfectly balanced again well quantified certainly proven source noise some models inherent resistance perfect balance such engines due nonlinear accelera tion forces piston offset connecting rod function rotation addition have torsional vibration created impulsive nature beasta phenomenon makes Perry vibrator fuel pump work well several ways alleviate problem First could go multiple cyl inders However very practical solution would still have torsional vibration although its frequency would crease function number firings per revolution Second could enclose engine exhaust system inside airframean effective strategy far goes still capable eliminating tor sional vibration Third could change well-balanced electric motor Electrics usually operate very smoothly Interest ingly too impulsive systems thus likewise exhibit torsional vibration higher frequency function number poles motor As mat ter fact knowledge everything life impulsive cyclic nature amazing think about far satisfactory solution air frame noise shield engine vibration airframe through use rubber metal isolators Several Pattern fliers have experimenting rubber en gine mounts various kinds have found case noise reduced Secondary perhaps primary bene fits isolation saving radio system failure eliminating incidence fuel foaming has struck down flier Also may prevent breakage loosening pushrod fittings engine mounts RPV project employed vibration isolation engine conse quently experienced no instance elec tronic failure due vibration Certainly worth price effort Isolating engine also removes very high-peak im pulsive loads engine permits much lighter less robust engine mount system Some will argue theyve tried Lord mounts found system wouldnt stay together response setup properly designed First mount systems natural frequency must outside operating frequency range engine harmonics can tear apart usually means very low soft frequency system Second peak loads iso lators must rupture rubber/metal bonds its important choose cor rect isolator task highly em pirical design solution cut try typ ical 60 engine installation uses three four liz- 9A6-in-diameter Lord mounts supporting engine radial mount fashion addition exhaust system pipe must rubber isolated also experiments quiet mufflers have found presence airframe noise testing engine mounted airplane versus testing engine mount significantly lessens noise reduc tion induced muffler air160 Model Aviation THERMAL CHARGER what looking electric sailplane good looks easy build fun fly great perfor mance Thermal Charger fl PRECISION PRODUCTS INC 714 592-5144 510 E Arrow Highway San Dimas CA 91773
Edition: Model Aviation - 1988/07
Page Numbers: 77, 78, 79, 159, 160
AA ior ventuz between EA AMA d45kidsb fas mating wor ~ m-ize home l airplanes L would like tr am like th area tion help u EBob Underwoo WHAT HAS FLIP slip 90 eyes its EAA Air Academy Weekend course problem answer prompts another question What Air Academy Weekend Perhaps next gaggle paragraphs will able bring activity focus years both modelers fullscalers have concerned about fact ranks AMA EAA have steadily increased number young people involved has kept pace Under leadership Experimental Aircraft Association education director Charles Larsen youth program has launched incorporates both full-scale modeling activity first pilot pro gram series four held Freder ick MD January 30-31 1988 AMA Friday evening January 29th some 45 volunteers interested parties gath ered classroom Aviation School Frederick Community College located Frederick Airport Chuck Larsen led meeting explained various parts program responsibilities involved video greeting featuring EAA officials Paul Tom Poberenzy stated reasons goals program During course evening Chuck asked person stand share some information about himself/herself proved interesting since con firmed thought shared Mr Larsen author two years ago person did identif himself either EAA AMA member could determine organization belonged solely background Indeed pre dicted some 15% attendance members both organizations Yes EAA AMA have much common Individuals move back forth between organizations interests change Sometimes full-scaler wants test ideas model form loses ticket health reasons takes up model ing other hand modelers accept challenge going aloft own crea tions turn EAA Other persons sharing stage eve ning Lance Zellers coordinated enrollments housing major de tails Phil Woodruff education director FAA representatives aviation insurers Avemco July 1988 77 Top Air Academy participants constructed full-size ribs home-built airplane hands-on projects during weekend Above Several lull-scale airplanes flown two-day event Jerry Blake aviation school administrator points out strut details Part three-hour modeling session contained some hangar talk about types mod els building techniques 45 flying buffs divided groups about 15 Saturday morning brought flurry ac tivity 45 young people ages 13 18 found way hangar di vided groups age assigned three activity sessions Air Academy Weekend under way should say wing session lasted three hours allowed ample time lec ture presentation actual building pe riod session led Chuck Larsen basically Mr Wizard type pro gram Through use kites hot air bal loons simple gliders presented history theory flight Plastic bags floated toward hangar roof kites wafted cool Maryland air gliders appropriate trim tabs circled classroom items ultimately faced aviation reality however landed second session led two BAA home-builders featured construction two full-scale parts full-sized wing rib built using truss construction Wood strips gussets glue nails combined make rib take shape second item young people made skid/slip indi cator found necessary AMAIEAA member Tom Crone explains sand wingtip Toms wife Krls also hand entire weekend help out cut file bend metal Combined wasa curved piece tubing glycerin BR screws pen used cali brate device third part activity sessions devoted modeling privileged lead program very ably sisted cadre AMA BAA mem bers started using 13-minute video produced National Geographic during 1986 Nats Lake Charles film speaks nonmodelers presents rather complete overview modeling disciplines includes everything door Formula 1 j Model Aviation Cresser helps outone c - pesky dihedral breaks CyA glues helped speed things up everyone got lesson much sawdust 15 people can make uuring break between sessions au thor launches Indoor Rubber Scale model borrowed Don Srull occasion ities between modeling full-scale avia tion followed film various forms model flying presented using Con trol Line Indoor Rubber Scale flew hangar Radio Control Watch future events areal Better yet model club EAA chapter would like participate contact AMA Technical Di rector Bob Underwood AMA Headquarters unit techniques explained new materials shown volunteers provided wide range models including some framed-up stage participant constructed Mid west Flip Hand-Launched Glider Thanks using cyanoacrylate CyA glues pro vided Carl Goldberg Models planes went together hour found 15 persons sanding once classroom can produce lot dust Once finished checked proper CG center-of gravity test glided hangar tossed skyward ramp front Inter estingly difficult get young folks throw hard experi enced satisfactory flight however also flew AMA Cub Delta Dart built helpers dur Continued page 159 July 1988 79 EAA Education Director Chuck Larsen sists Intense student launching hot-air balloon part Mr Wizard session history theory aviation John Patton former AMA president checks see center gravity CG came out right place before test flying Flip Hand-Launched Glider Midwest donated models Can stage anynvwvng teennui nyThe modest registra tion fee inciuaea aii ihe materials bui nree meals during two-day program CL Speed/Hempel Continued page 69 Automotive Devices CAD Indiana Curtis hired Paul Frank Aeromarine/Shev uns chief engineer aid transfer mate rial technology Bedford located southcentral Indiana eight Shevlin people Paul asked accompany him three us did CAD Dyna-Fog Dyna-Jet re turned production after long delay re search begun smaller versions both Ad ditionally pulsejet-powered steam generator being considered drafting department expanded hiring man working engineering degree also familiar Dyna-Jet having won Jet Speed events previous subsequent years refer James Richmond currently very ac tive successful national international Indoor FF competition year-and-a-half after move Bedford Paul Frank remained others us hav ing left various reasons Prototype small Dyna-Fog machines fabricated refinement begun preparation quantity pro duction However other research pulsejet projects halted including smaller Dyna-Jet Several years later ironically modestly successful Japanese-made Tigeriet placed sale country few years later Curtis moved company Westfield located just north Indianapolis changed company name Curtis Dyna Products Presumably acknowledge ment renewed importance company creations ideas Aeromarine Shevlin remains named today although Mr Curtis passed away few years ago am unaware current products projects Curtis Dyna-Products know extensive changes Dyna-Fog series Only Dyna-Jet same years ago probable improved technoques have adopted some production steps far can learn item Dyna-Jet ever pro duced interchangeable its counterpart other Indeed parts its foreign clones least three also fully interchangeableeven use US stan dard threads metricized country after 40 years almost continuous production days successful competitors Jet Speed extensively modify engines Among other things concoct fuel blends make bigger bang does gasoline ap plication seems safe say however manufactured properly used Dyna-Jet re mains easiest-starting consistent performance reliable safest eeonomical operate minlature power plant ever placed production Once again want thank Gerald L Jerry Wiles sharing fascinating bit personal history us love cards letters photos send Weekend/Underwood Continued page 79 ing talking presentation Along taxied wingless RC modelwe too close active runway fly Parked airplanes snow prevented us flying Control Line well Something very significant occurred break after sessions young people models hand gravitated AMA room studied mod els display importantly repaired modified model built Flip became Stealth-type air craft through ingenious use scrap balsa conclusion model session participant given goody bun dle containing AMA material copy Model Aviaf ion AMA Cub build home program covered 10 hours Satur day lunch dinner served hangar airport restaurant Saturday eve ning featured wind-up session films brief comments Sunday third session held morning noon lunch shared participants parents volunteers Hangar talk abounded everyone opportunity look over several full-scale aircraft flown day three afternoon everyone headed home savoring experi ences first Air Academy Weekend clean-up session helpers fol lowed pleasant dinner local restaur ant table talk bubbled suc cess weekends event person whether EAAer AMAer said next program occurred area wanted part seeond four pilot programs held Minneapolis-St Paul area end February modeling ses sion being led Boyd Bowdish District VII assistant vice-president Two will held Tulsa OK Indianapolis IN later year What come Plans under way within EAA expand program AMA pleased have opportunity participate effort utilize talents MIhIJET SERIESThe Proud Bird theProud Bird planes feature balsadesIgned meet constructIon Designed ith the0lPR5 Formula intermediate flyer mind ,ill 120 ralesThls 1/i arcept 21 25 size engineCase ,tTZJscale model hill accept o reur eahaust engine em 60120 ci size engines ceptiseul perfuraanceDet al l~uo5o.Epoap glass faselagewlth t5rill jet elthou t foam wIng constructIon Full kIt $15000 toe hassles darted fan SoyhamiSemIkIt also avaIlaBle Ino mood $12511 Special Introductory PrIce Please add $1000 shIppIng handling sillS plus $300 IBM flu hes Send check Md add dl sales too Mastercard PIsa SOOLE MametS coo add $200 t3BSSBIM477 PARRISH AIRCRAFT fop Turkey formula 1 dDart EaperimentalI2ssW491hre, ISSOD dhTigersharktwoplace full sIze aIrcraftPInIatiaeFj 3331 July 1988 159 both EAA chapters AMA charter clubs exchanging list ings club chapter would like participate activities directed toward youth contact Bob Under wood AMA Technical Director 1810 Sam uel Morse Dr Reston VA 22090 terrific experience About Noise/Lowe Continued page 91 engine does mean anti Electrics great low-energy ap plications Still will never match energy-per-pound ratio piston en gine simply because no known bat tery energy density alcohol gasoline fuel Some years ago involved de velopment RPV using ad vanced lithium hydride very dangerous battery system concert ad vanced motor design around cobalt turned prop same rpm com parable piston engine found RPV system approximately noisy piston engine setup addition RPV netted about 25% energy density piston engine gasoline setup other words Electric system 300 watt hours per pound would operate just 25% duration piston en gine equivalent weight Furthermore Ni-Cd batteries used models have far less energy high-performance lithium hydride batteries tested Four-stroke engines usually credited being quieter two-stroke ones testing has contradicted assumption given rpm primary sound frequency typical four-stroke engine half two-stroke may fact sound pleasant measured dB levels prove comparable fact some Pat tern fliers have shied away four-stroke engines because too noisy Remem ber dB meter scale does compen sate perceived sound lowering its re sponse lower frequencies since tries simulate human response Most four-stroke Pattern fliers using high prop pitch 1112 less diameter reduce rpm noise Four-strokers have mechanical noise addition suspect generate airframe noise due higher vibration Check out prop diameter rpm tip velocity typical four-stroke engine Youll find higher typical two-stroke F3A Pattern ship setup What modeling world needs greater availability high-quality stiff high-pitch props Various measures can taken reduce engine mechanical noisesthose radiated propulsion system surfaces such bearings etcas well sound radiation walls engine muffler pipe forth lack well-quantified data area have seen 2-dR noise re duction replacing noisy bearings new ones 1- 2-dB drop using rub ber sleeve tuned pipe 1-dB reduc tion using filter intake pri mary focus quest sound reduc tion should course having quality muffler getting propeller tip speed down ancillary modifications should also considered Airframe noise generated thrash ing single-cylinder model engine design cannot perfectly balanced again well quantified certainly proven source noise some models inherent resistance perfect balance such engines due nonlinear accelera tion forces piston offset connecting rod function rotation addition have torsional vibration created impulsive nature beasta phenomenon makes Perry vibrator fuel pump work well several ways alleviate problem First could go multiple cyl inders However very practical solution would still have torsional vibration although its frequency would crease function number firings per revolution Second could enclose engine exhaust system inside airframean effective strategy far goes still capable eliminating tor sional vibration Third could change well-balanced electric motor Electrics usually operate very smoothly Interest ingly too impulsive systems thus likewise exhibit torsional vibration higher frequency function number poles motor As mat ter fact knowledge everything life impulsive cyclic nature amazing think about far satisfactory solution air frame noise shield engine vibration airframe through use rubber metal isolators Several Pattern fliers have experimenting rubber en gine mounts various kinds have found case noise reduced Secondary perhaps primary bene fits isolation saving radio system failure eliminating incidence fuel foaming has struck down flier Also may prevent breakage loosening pushrod fittings engine mounts RPV project employed vibration isolation engine conse quently experienced no instance elec tronic failure due vibration Certainly worth price effort Isolating engine also removes very high-peak im pulsive loads engine permits much lighter less robust engine mount system Some will argue theyve tried Lord mounts found system wouldnt stay together response setup properly designed First mount systems natural frequency must outside operating frequency range engine harmonics can tear apart usually means very low soft frequency system Second peak loads iso lators must rupture rubber/metal bonds its important choose cor rect isolator task highly em pirical design solution cut try typ ical 60 engine installation uses three four liz- 9A6-in-diameter Lord mounts supporting engine radial mount fashion addition exhaust system pipe must rubber isolated also experiments quiet mufflers have found presence airframe noise testing engine mounted airplane versus testing engine mount significantly lessens noise reduc tion induced muffler air160 Model Aviation THERMAL CHARGER what looking electric sailplane good looks easy build fun fly great perfor mance Thermal Charger fl PRECISION PRODUCTS INC 714 592-5144 510 E Arrow Highway San Dimas CA 91773
Edition: Model Aviation - 1988/07
Page Numbers: 77, 78, 79, 159, 160
AA ior ventuz between EA AMA d45kidsb fas mating wor ~ m-ize home l airplanes L would like tr am like th area tion help u EBob Underwoo WHAT HAS FLIP slip 90 eyes its EAA Air Academy Weekend course problem answer prompts another question What Air Academy Weekend Perhaps next gaggle paragraphs will able bring activity focus years both modelers fullscalers have concerned about fact ranks AMA EAA have steadily increased number young people involved has kept pace Under leadership Experimental Aircraft Association education director Charles Larsen youth program has launched incorporates both full-scale modeling activity first pilot pro gram series four held Freder ick MD January 30-31 1988 AMA Friday evening January 29th some 45 volunteers interested parties gath ered classroom Aviation School Frederick Community College located Frederick Airport Chuck Larsen led meeting explained various parts program responsibilities involved video greeting featuring EAA officials Paul Tom Poberenzy stated reasons goals program During course evening Chuck asked person stand share some information about himself/herself proved interesting since con firmed thought shared Mr Larsen author two years ago person did identif himself either EAA AMA member could determine organization belonged solely background Indeed pre dicted some 15% attendance members both organizations Yes EAA AMA have much common Individuals move back forth between organizations interests change Sometimes full-scaler wants test ideas model form loses ticket health reasons takes up model ing other hand modelers accept challenge going aloft own crea tions turn EAA Other persons sharing stage eve ning Lance Zellers coordinated enrollments housing major de tails Phil Woodruff education director FAA representatives aviation insurers Avemco July 1988 77 Top Air Academy participants constructed full-size ribs home-built airplane hands-on projects during weekend Above Several lull-scale airplanes flown two-day event Jerry Blake aviation school administrator points out strut details Part three-hour modeling session contained some hangar talk about types mod els building techniques 45 flying buffs divided groups about 15 Saturday morning brought flurry ac tivity 45 young people ages 13 18 found way hangar di vided groups age assigned three activity sessions Air Academy Weekend under way should say wing session lasted three hours allowed ample time lec ture presentation actual building pe riod session led Chuck Larsen basically Mr Wizard type pro gram Through use kites hot air bal loons simple gliders presented history theory flight Plastic bags floated toward hangar roof kites wafted cool Maryland air gliders appropriate trim tabs circled classroom items ultimately faced aviation reality however landed second session led two BAA home-builders featured construction two full-scale parts full-sized wing rib built using truss construction Wood strips gussets glue nails combined make rib take shape second item young people made skid/slip indi cator found necessary AMAIEAA member Tom Crone explains sand wingtip Toms wife Krls also hand entire weekend help out cut file bend metal Combined wasa curved piece tubing glycerin BR screws pen used cali brate device third part activity sessions devoted modeling privileged lead program very ably sisted cadre AMA BAA mem bers started using 13-minute video produced National Geographic during 1986 Nats Lake Charles film speaks nonmodelers presents rather complete overview modeling disciplines includes everything door Formula 1 j Model Aviation Cresser helps outone c - pesky dihedral breaks CyA glues helped speed things up everyone got lesson much sawdust 15 people can make uuring break between sessions au thor launches Indoor Rubber Scale model borrowed Don Srull occasion ities between modeling full-scale avia tion followed film various forms model flying presented using Con trol Line Indoor Rubber Scale flew hangar Radio Control Watch future events areal Better yet model club EAA chapter would like participate contact AMA Technical Di rector Bob Underwood AMA Headquarters unit techniques explained new materials shown volunteers provided wide range models including some framed-up stage participant constructed Mid west Flip Hand-Launched Glider Thanks using cyanoacrylate CyA glues pro vided Carl Goldberg Models planes went together hour found 15 persons sanding once classroom can produce lot dust Once finished checked proper CG center-of gravity test glided hangar tossed skyward ramp front Inter estingly difficult get young folks throw hard experi enced satisfactory flight however also flew AMA Cub Delta Dart built helpers dur Continued page 159 July 1988 79 EAA Education Director Chuck Larsen sists Intense student launching hot-air balloon part Mr Wizard session history theory aviation John Patton former AMA president checks see center gravity CG came out right place before test flying Flip Hand-Launched Glider Midwest donated models Can stage anynvwvng teennui nyThe modest registra tion fee inciuaea aii ihe materials bui nree meals during two-day program CL Speed/Hempel Continued page 69 Automotive Devices CAD Indiana Curtis hired Paul Frank Aeromarine/Shev uns chief engineer aid transfer mate rial technology Bedford located southcentral Indiana eight Shevlin people Paul asked accompany him three us did CAD Dyna-Fog Dyna-Jet re turned production after long delay re search begun smaller versions both Ad ditionally pulsejet-powered steam generator being considered drafting department expanded hiring man working engineering degree also familiar Dyna-Jet having won Jet Speed events previous subsequent years refer James Richmond currently very ac tive successful national international Indoor FF competition year-and-a-half after move Bedford Paul Frank remained others us hav ing left various reasons Prototype small Dyna-Fog machines fabricated refinement begun preparation quantity pro duction However other research pulsejet projects halted including smaller Dyna-Jet Several years later ironically modestly successful Japanese-made Tigeriet placed sale country few years later Curtis moved company Westfield located just north Indianapolis changed company name Curtis Dyna Products Presumably acknowledge ment renewed importance company creations ideas Aeromarine Shevlin remains named today although Mr Curtis passed away few years ago am unaware current products projects Curtis Dyna-Products know extensive changes Dyna-Fog series Only Dyna-Jet same years ago probable improved technoques have adopted some production steps far can learn item Dyna-Jet ever pro duced interchangeable its counterpart other Indeed parts its foreign clones least three also fully interchangeableeven use US stan dard threads metricized country after 40 years almost continuous production days successful competitors Jet Speed extensively modify engines Among other things concoct fuel blends make bigger bang does gasoline ap plication seems safe say however manufactured properly used Dyna-Jet re mains easiest-starting consistent performance reliable safest eeonomical operate minlature power plant ever placed production Once again want thank Gerald L Jerry Wiles sharing fascinating bit personal history us love cards letters photos send Weekend/Underwood Continued page 79 ing talking presentation Along taxied wingless RC modelwe too close active runway fly Parked airplanes snow prevented us flying Control Line well Something very significant occurred break after sessions young people models hand gravitated AMA room studied mod els display importantly repaired modified model built Flip became Stealth-type air craft through ingenious use scrap balsa conclusion model session participant given goody bun dle containing AMA material copy Model Aviaf ion AMA Cub build home program covered 10 hours Satur day lunch dinner served hangar airport restaurant Saturday eve ning featured wind-up session films brief comments Sunday third session held morning noon lunch shared participants parents volunteers Hangar talk abounded everyone opportunity look over several full-scale aircraft flown day three afternoon everyone headed home savoring experi ences first Air Academy Weekend clean-up session helpers fol lowed pleasant dinner local restaur ant table talk bubbled suc cess weekends event person whether EAAer AMAer said next program occurred area wanted part seeond four pilot programs held Minneapolis-St Paul area end February modeling ses sion being led Boyd Bowdish District VII assistant vice-president Two will held Tulsa OK Indianapolis IN later year What come Plans under way within EAA expand program AMA pleased have opportunity participate effort utilize talents MIhIJET SERIESThe Proud Bird theProud Bird planes feature balsadesIgned meet constructIon Designed ith the0lPR5 Formula intermediate flyer mind ,ill 120 ralesThls 1/i arcept 21 25 size engineCase ,tTZJscale model hill accept o reur eahaust engine em 60120 ci size engines ceptiseul perfuraanceDet al l~uo5o.Epoap glass faselagewlth t5rill jet elthou t foam wIng constructIon Full kIt $15000 toe hassles darted fan SoyhamiSemIkIt also avaIlaBle Ino mood $12511 Special Introductory PrIce Please add $1000 shIppIng handling sillS plus $300 IBM flu hes Send check Md add dl sales too Mastercard PIsa SOOLE MametS coo add $200 t3BSSBIM477 PARRISH AIRCRAFT fop Turkey formula 1 dDart EaperimentalI2ssW491hre, ISSOD dhTigersharktwoplace full sIze aIrcraftPInIatiaeFj 3331 July 1988 159 both EAA chapters AMA charter clubs exchanging list ings club chapter would like participate activities directed toward youth contact Bob Under wood AMA Technical Director 1810 Sam uel Morse Dr Reston VA 22090 terrific experience About Noise/Lowe Continued page 91 engine does mean anti Electrics great low-energy ap plications Still will never match energy-per-pound ratio piston en gine simply because no known bat tery energy density alcohol gasoline fuel Some years ago involved de velopment RPV using ad vanced lithium hydride very dangerous battery system concert ad vanced motor design around cobalt turned prop same rpm com parable piston engine found RPV system approximately noisy piston engine setup addition RPV netted about 25% energy density piston engine gasoline setup other words Electric system 300 watt hours per pound would operate just 25% duration piston en gine equivalent weight Furthermore Ni-Cd batteries used models have far less energy high-performance lithium hydride batteries tested Four-stroke engines usually credited being quieter two-stroke ones testing has contradicted assumption given rpm primary sound frequency typical four-stroke engine half two-stroke may fact sound pleasant measured dB levels prove comparable fact some Pat tern fliers have shied away four-stroke engines because too noisy Remem ber dB meter scale does compen sate perceived sound lowering its re sponse lower frequencies since tries simulate human response Most four-stroke Pattern fliers using high prop pitch 1112 less diameter reduce rpm noise Four-strokers have mechanical noise addition suspect generate airframe noise due higher vibration Check out prop diameter rpm tip velocity typical four-stroke engine Youll find higher typical two-stroke F3A Pattern ship setup What modeling world needs greater availability high-quality stiff high-pitch props Various measures can taken reduce engine mechanical noisesthose radiated propulsion system surfaces such bearings etcas well sound radiation walls engine muffler pipe forth lack well-quantified data area have seen 2-dR noise re duction replacing noisy bearings new ones 1- 2-dB drop using rub ber sleeve tuned pipe 1-dB reduc tion using filter intake pri mary focus quest sound reduc tion should course having quality muffler getting propeller tip speed down ancillary modifications should also considered Airframe noise generated thrash ing single-cylinder model engine design cannot perfectly balanced again well quantified certainly proven source noise some models inherent resistance perfect balance such engines due nonlinear accelera tion forces piston offset connecting rod function rotation addition have torsional vibration created impulsive nature beasta phenomenon makes Perry vibrator fuel pump work well several ways alleviate problem First could go multiple cyl inders However very practical solution would still have torsional vibration although its frequency would crease function number firings per revolution Second could enclose engine exhaust system inside airframean effective strategy far goes still capable eliminating tor sional vibration Third could change well-balanced electric motor Electrics usually operate very smoothly Interest ingly too impulsive systems thus likewise exhibit torsional vibration higher frequency function number poles motor As mat ter fact knowledge everything life impulsive cyclic nature amazing think about far satisfactory solution air frame noise shield engine vibration airframe through use rubber metal isolators Several Pattern fliers have experimenting rubber en gine mounts various kinds have found case noise reduced Secondary perhaps primary bene fits isolation saving radio system failure eliminating incidence fuel foaming has struck down flier Also may prevent breakage loosening pushrod fittings engine mounts RPV project employed vibration isolation engine conse quently experienced no instance elec tronic failure due vibration Certainly worth price effort Isolating engine also removes very high-peak im pulsive loads engine permits much lighter less robust engine mount system Some will argue theyve tried Lord mounts found system wouldnt stay together response setup properly designed First mount systems natural frequency must outside operating frequency range engine harmonics can tear apart usually means very low soft frequency system Second peak loads iso lators must rupture rubber/metal bonds its important choose cor rect isolator task highly em pirical design solution cut try typ ical 60 engine installation uses three four liz- 9A6-in-diameter Lord mounts supporting engine radial mount fashion addition exhaust system pipe must rubber isolated also experiments quiet mufflers have found presence airframe noise testing engine mounted airplane versus testing engine mount significantly lessens noise reduc tion induced muffler air160 Model Aviation THERMAL CHARGER what looking electric sailplane good looks easy build fun fly great perfor mance Thermal Charger fl PRECISION PRODUCTS INC 714 592-5144 510 E Arrow Highway San Dimas CA 91773
Edition: Model Aviation - 1988/07
Page Numbers: 77, 78, 79, 159, 160
AA ior ventuz between EA AMA d45kidsb fas mating wor ~ m-ize home l airplanes L would like tr am like th area tion help u EBob Underwoo WHAT HAS FLIP slip 90 eyes its EAA Air Academy Weekend course problem answer prompts another question What Air Academy Weekend Perhaps next gaggle paragraphs will able bring activity focus years both modelers fullscalers have concerned about fact ranks AMA EAA have steadily increased number young people involved has kept pace Under leadership Experimental Aircraft Association education director Charles Larsen youth program has launched incorporates both full-scale modeling activity first pilot pro gram series four held Freder ick MD January 30-31 1988 AMA Friday evening January 29th some 45 volunteers interested parties gath ered classroom Aviation School Frederick Community College located Frederick Airport Chuck Larsen led meeting explained various parts program responsibilities involved video greeting featuring EAA officials Paul Tom Poberenzy stated reasons goals program During course evening Chuck asked person stand share some information about himself/herself proved interesting since con firmed thought shared Mr Larsen author two years ago person did identif himself either EAA AMA member could determine organization belonged solely background Indeed pre dicted some 15% attendance members both organizations Yes EAA AMA have much common Individuals move back forth between organizations interests change Sometimes full-scaler wants test ideas model form loses ticket health reasons takes up model ing other hand modelers accept challenge going aloft own crea tions turn EAA Other persons sharing stage eve ning Lance Zellers coordinated enrollments housing major de tails Phil Woodruff education director FAA representatives aviation insurers Avemco July 1988 77 Top Air Academy participants constructed full-size ribs home-built airplane hands-on projects during weekend Above Several lull-scale airplanes flown two-day event Jerry Blake aviation school administrator points out strut details Part three-hour modeling session contained some hangar talk about types mod els building techniques 45 flying buffs divided groups about 15 Saturday morning brought flurry ac tivity 45 young people ages 13 18 found way hangar di vided groups age assigned three activity sessions Air Academy Weekend under way should say wing session lasted three hours allowed ample time lec ture presentation actual building pe riod session led Chuck Larsen basically Mr Wizard type pro gram Through use kites hot air bal loons simple gliders presented history theory flight Plastic bags floated toward hangar roof kites wafted cool Maryland air gliders appropriate trim tabs circled classroom items ultimately faced aviation reality however landed second session led two BAA home-builders featured construction two full-scale parts full-sized wing rib built using truss construction Wood strips gussets glue nails combined make rib take shape second item young people made skid/slip indi cator found necessary AMAIEAA member Tom Crone explains sand wingtip Toms wife Krls also hand entire weekend help out cut file bend metal Combined wasa curved piece tubing glycerin BR screws pen used cali brate device third part activity sessions devoted modeling privileged lead program very ably sisted cadre AMA BAA mem bers started using 13-minute video produced National Geographic during 1986 Nats Lake Charles film speaks nonmodelers presents rather complete overview modeling disciplines includes everything door Formula 1 j Model Aviation Cresser helps outone c - pesky dihedral breaks CyA glues helped speed things up everyone got lesson much sawdust 15 people can make uuring break between sessions au thor launches Indoor Rubber Scale model borrowed Don Srull occasion ities between modeling full-scale avia tion followed film various forms model flying presented using Con trol Line Indoor Rubber Scale flew hangar Radio Control Watch future events areal Better yet model club EAA chapter would like participate contact AMA Technical Di rector Bob Underwood AMA Headquarters unit techniques explained new materials shown volunteers provided wide range models including some framed-up stage participant constructed Mid west Flip Hand-Launched Glider Thanks using cyanoacrylate CyA glues pro vided Carl Goldberg Models planes went together hour found 15 persons sanding once classroom can produce lot dust Once finished checked proper CG center-of gravity test glided hangar tossed skyward ramp front Inter estingly difficult get young folks throw hard experi enced satisfactory flight however also flew AMA Cub Delta Dart built helpers dur Continued page 159 July 1988 79 EAA Education Director Chuck Larsen sists Intense student launching hot-air balloon part Mr Wizard session history theory aviation John Patton former AMA president checks see center gravity CG came out right place before test flying Flip Hand-Launched Glider Midwest donated models Can stage anynvwvng teennui nyThe modest registra tion fee inciuaea aii ihe materials bui nree meals during two-day program CL Speed/Hempel Continued page 69 Automotive Devices CAD Indiana Curtis hired Paul Frank Aeromarine/Shev uns chief engineer aid transfer mate rial technology Bedford located southcentral Indiana eight Shevlin people Paul asked accompany him three us did CAD Dyna-Fog Dyna-Jet re turned production after long delay re search begun smaller versions both Ad ditionally pulsejet-powered steam generator being considered drafting department expanded hiring man working engineering degree also familiar Dyna-Jet having won Jet Speed events previous subsequent years refer James Richmond currently very ac tive successful national international Indoor FF competition year-and-a-half after move Bedford Paul Frank remained others us hav ing left various reasons Prototype small Dyna-Fog machines fabricated refinement begun preparation quantity pro duction However other research pulsejet projects halted including smaller Dyna-Jet Several years later ironically modestly successful Japanese-made Tigeriet placed sale country few years later Curtis moved company Westfield located just north Indianapolis changed company name Curtis Dyna Products Presumably acknowledge ment renewed importance company creations ideas Aeromarine Shevlin remains named today although Mr Curtis passed away few years ago am unaware current products projects Curtis Dyna-Products know extensive changes Dyna-Fog series Only Dyna-Jet same years ago probable improved technoques have adopted some production steps far can learn item Dyna-Jet ever pro duced interchangeable its counterpart other Indeed parts its foreign clones least three also fully interchangeableeven use US stan dard threads metricized country after 40 years almost continuous production days successful competitors Jet Speed extensively modify engines Among other things concoct fuel blends make bigger bang does gasoline ap plication seems safe say however manufactured properly used Dyna-Jet re mains easiest-starting consistent performance reliable safest eeonomical operate minlature power plant ever placed production Once again want thank Gerald L Jerry Wiles sharing fascinating bit personal history us love cards letters photos send Weekend/Underwood Continued page 79 ing talking presentation Along taxied wingless RC modelwe too close active runway fly Parked airplanes snow prevented us flying Control Line well Something very significant occurred break after sessions young people models hand gravitated AMA room studied mod els display importantly repaired modified model built Flip became Stealth-type air craft through ingenious use scrap balsa conclusion model session participant given goody bun dle containing AMA material copy Model Aviaf ion AMA Cub build home program covered 10 hours Satur day lunch dinner served hangar airport restaurant Saturday eve ning featured wind-up session films brief comments Sunday third session held morning noon lunch shared participants parents volunteers Hangar talk abounded everyone opportunity look over several full-scale aircraft flown day three afternoon everyone headed home savoring experi ences first Air Academy Weekend clean-up session helpers fol lowed pleasant dinner local restaur ant table talk bubbled suc cess weekends event person whether EAAer AMAer said next program occurred area wanted part seeond four pilot programs held Minneapolis-St Paul area end February modeling ses sion being led Boyd Bowdish District VII assistant vice-president Two will held Tulsa OK Indianapolis IN later year What come Plans under way within EAA expand program AMA pleased have opportunity participate effort utilize talents MIhIJET SERIESThe Proud Bird theProud Bird planes feature balsadesIgned meet constructIon Designed ith the0lPR5 Formula intermediate flyer mind ,ill 120 ralesThls 1/i arcept 21 25 size engineCase ,tTZJscale model hill accept o reur eahaust engine em 60120 ci size engines ceptiseul perfuraanceDet al l~uo5o.Epoap glass faselagewlth t5rill jet elthou t foam wIng constructIon Full kIt $15000 toe hassles darted fan SoyhamiSemIkIt also avaIlaBle Ino mood $12511 Special Introductory PrIce Please add $1000 shIppIng handling sillS plus $300 IBM flu hes Send check Md add dl sales too Mastercard PIsa SOOLE MametS coo add $200 t3BSSBIM477 PARRISH AIRCRAFT fop Turkey formula 1 dDart EaperimentalI2ssW491hre, ISSOD dhTigersharktwoplace full sIze aIrcraftPInIatiaeFj 3331 July 1988 159 both EAA chapters AMA charter clubs exchanging list ings club chapter would like participate activities directed toward youth contact Bob Under wood AMA Technical Director 1810 Sam uel Morse Dr Reston VA 22090 terrific experience About Noise/Lowe Continued page 91 engine does mean anti Electrics great low-energy ap plications Still will never match energy-per-pound ratio piston en gine simply because no known bat tery energy density alcohol gasoline fuel Some years ago involved de velopment RPV using ad vanced lithium hydride very dangerous battery system concert ad vanced motor design around cobalt turned prop same rpm com parable piston engine found RPV system approximately noisy piston engine setup addition RPV netted about 25% energy density piston engine gasoline setup other words Electric system 300 watt hours per pound would operate just 25% duration piston en gine equivalent weight Furthermore Ni-Cd batteries used models have far less energy high-performance lithium hydride batteries tested Four-stroke engines usually credited being quieter two-stroke ones testing has contradicted assumption given rpm primary sound frequency typical four-stroke engine half two-stroke may fact sound pleasant measured dB levels prove comparable fact some Pat tern fliers have shied away four-stroke engines because too noisy Remem ber dB meter scale does compen sate perceived sound lowering its re sponse lower frequencies since tries simulate human response Most four-stroke Pattern fliers using high prop pitch 1112 less diameter reduce rpm noise Four-strokers have mechanical noise addition suspect generate airframe noise due higher vibration Check out prop diameter rpm tip velocity typical four-stroke engine Youll find higher typical two-stroke F3A Pattern ship setup What modeling world needs greater availability high-quality stiff high-pitch props Various measures can taken reduce engine mechanical noisesthose radiated propulsion system surfaces such bearings etcas well sound radiation walls engine muffler pipe forth lack well-quantified data area have seen 2-dR noise re duction replacing noisy bearings new ones 1- 2-dB drop using rub ber sleeve tuned pipe 1-dB reduc tion using filter intake pri mary focus quest sound reduc tion should course having quality muffler getting propeller tip speed down ancillary modifications should also considered Airframe noise generated thrash ing single-cylinder model engine design cannot perfectly balanced again well quantified certainly proven source noise some models inherent resistance perfect balance such engines due nonlinear accelera tion forces piston offset connecting rod function rotation addition have torsional vibration created impulsive nature beasta phenomenon makes Perry vibrator fuel pump work well several ways alleviate problem First could go multiple cyl inders However very practical solution would still have torsional vibration although its frequency would crease function number firings per revolution Second could enclose engine exhaust system inside airframean effective strategy far goes still capable eliminating tor sional vibration Third could change well-balanced electric motor Electrics usually operate very smoothly Interest ingly too impulsive systems thus likewise exhibit torsional vibration higher frequency function number poles motor As mat ter fact knowledge everything life impulsive cyclic nature amazing think about far satisfactory solution air frame noise shield engine vibration airframe through use rubber metal isolators Several Pattern fliers have experimenting rubber en gine mounts various kinds have found case noise reduced Secondary perhaps primary bene fits isolation saving radio system failure eliminating incidence fuel foaming has struck down flier Also may prevent breakage loosening pushrod fittings engine mounts RPV project employed vibration isolation engine conse quently experienced no instance elec tronic failure due vibration Certainly worth price effort Isolating engine also removes very high-peak im pulsive loads engine permits much lighter less robust engine mount system Some will argue theyve tried Lord mounts found system wouldnt stay together response setup properly designed First mount systems natural frequency must outside operating frequency range engine harmonics can tear apart usually means very low soft frequency system Second peak loads iso lators must rupture rubber/metal bonds its important choose cor rect isolator task highly em pirical design solution cut try typ ical 60 engine installation uses three four liz- 9A6-in-diameter Lord mounts supporting engine radial mount fashion addition exhaust system pipe must rubber isolated also experiments quiet mufflers have found presence airframe noise testing engine mounted airplane versus testing engine mount significantly lessens noise reduc tion induced muffler air160 Model Aviation THERMAL CHARGER what looking electric sailplane good looks easy build fun fly great perfor mance Thermal Charger fl PRECISION PRODUCTS INC 714 592-5144 510 E Arrow Highway San Dimas CA 91773