Noiseand Aircraft U Noise Committee RC Flying Club Toronto CASE STUDY Flying Field Saved Just about everyone concerned about pollution waste water air noise Flying sites have lost being lost will lost unless can come up some answers Once flying sites easy find around urban areas Now population growth increased activity hobby urban sprawl just about impossible find keep site within reasonable driving distance apparent continue enjoying hobby must learn quiet op eration Armed sound level meters set out find what up against Tests showed 40-sized engine its standard factory-supplied muffler meas ured seven meters distance meter off ground registered 86 93 dRa 60-sized engine its muffler registered 89 96 dRa choose seven meters distance meter off ground FM has spot check 105 dBa measured meter ground found too much room error slightest variance distance angie meter would give vastly different readings Also FAI check supposed made concrete blacktop fields dont have seven- one-meter measurement simple quick used successfully several European countries Exhaust gases major source noise what about prop noise What about intake noise What about con struction aircraft con tribute overall noise level much Lets look time Exhaust gases Mufflers quiet sound allowing gases slowly expand cool bigger muffler better works Most mufflers use large enough effective beyond 12000 rpm point gases being pushed through engine fast have little time expansion cooling leads us next item Prop noise 12000 rpm up prop noise becomes contributing factor degree people think Much sharp increase noise level evident higher rpm has often blamed prop case cars boats noisy higher rpm tests using electric motors swung props up 14000 rpm found although noise definitely fairly lowpitched noise does carry few hundred feet What about pitch Lets back up step two Noise least its nuisance value comprised two parts volume loudness pitch frequency example driving car 60mph window open produces noise level excess 90 dBa uncomfortable because low pitch other hand microphone feedback PA system unbearable because its high pitch good example short range prop noise four-stroke engines four-stroker flies can hear prop noise As soon few hundred feet away prop noise disap pears whereas engine noise continues Tatake aoise unable prove intake noise significant contrib uting factor until aircraft approaches 80 dBa noise level lower Aircraft coastructioa does have effect overall noise produced take dBa reading particular engine muffler mounted openstructured aircraft mount same combination aircraft solid sides foam-core wing dBa reading second will quieter Once again though drum effect fabricor heat-shrink-covered open-structured air craft low-pitched sound small contributor overall scene apparent continue enjoying hobby must learn quiet operation Thus far have discussed noise produced craft itself large contributing factor overall nuisance value given aircraft flown stands reason particularly noisy aircraft taken off full power throttled back half flown low close will cause less annoyance quieter theory aircraft flown far field full throttle high altitudes enlightening experience stand half-mile flying site note just aircraft offenders soon becomes obvious altitude large factor thinking about however recall last time observed full-size aircraft take off long distance see quite some time before sound heard Continued page 14 12 Model Aviation Hobby Lobbys Guest Editoria IQJ MINI-SERIES RICI HLRM1 320 Mini-Series F-4 PHANTOM$4400 High film strength lubricant increased power long engine life Detergents cut performance robbing varnish Highest quality ingredients insure top engine performance reliability Anti-foam additives prevent high RPM lean out Rust preventatives protect expensive engines TypeNitro 0/oLubricant4 Gal24 Gal64 Gal124 Gal FAI0%Synthetic$675$595$575$550 5s50/0Synthetic$775$695$675$650 Sc50/aCastor Oil$775$695$675$650 4-cycle70/aCastor/Syn$850$765$750$725 4-cycle150/0Castor/Syn$995$895$850$825 lOs100hSynthetic$895$795$750$725 lOc100/0Castor Oil$895$795$750$725 R/O120/oSyn/Castor$995$895$850$825 iSs150/0Synthetic$995$895$850$825 20c200/aCastor Oil$1395$1250$1200$1150 25s250/aSynthetic$1495$1350$1300$1250 4040%15 Syn-5 Castor$1995$1795$1750$1700 50S00/oSynthetic$2395$2100$2050$2000 60600/0Synthetic$2695$2400$2300$2200 HIN CONTINENTAL USA SHELDONS rs HOBBY SHOPMon Wed Fri & Sat M/C VISA 0 530 24-124 Gal 3157 Alum Rock AvenueThur 930-900 shipped via truck San Jose California 95127Sun 1200-500 UPS COD $165408 251-0787 ENGLISH FLAIR KITS Kits feature pre-cut Balsa & Ply Parts Formed Wire ware Furnished Spun Aluminum Cowl s Detailed plans show fully enclosed 4 stroke motor 4 models series See dealer write deatils Dealers inquire PUPPETEER $98g5 30-45 2 stroke motor 40-60 4 stroke motor VIA MORLEY ARCHOALE DR LOTTE NC 28210 happens aircraft attains higher alti tudes same true model aircraft tests showed noisy craft over 92 dBa could heard onehalf mile stayed below 200 ft ever 200 ft altitude isnt much dont expect everyone go around cutting grass props lets look some other solutions First needed goal Since 40-size smaller engines will pass 88 dBa level little no adjustment chose initial level would cut current average noise levels half Since exhaust prime cause noise attacked first using muffler works using two has work better quite dramatically Aircraft producing well excess 88 dRa reduced near 80 dBa Also method very little loss rpm second add-on muffler need fancy butane lighter refill can similar small can pipe sol dered epoxied end coupled primary muffler silicone tubing works fine 1/16-IN HOLES SIUCONE TUBE drawback foregoing its aesthetic value Its always hard enough hide muffler Scale ship can hide two Try small add-on made couple inches brass tubing 35 clamp small amount steel wool 00 size method will efficient double muffler has added ad vantage being adjustable drawback although can regulate dBa level produced amount steel wool used proportionate drop rpm Care should taken use too much steel wool very little needed rpm drops excess 1000 may cause overheating SOWER CAP Baffled mufflers Some fliers have cut mufflers half added divider middle make dual-chambered muffler once again efficient double-muffler system will get engines under 88 dRa mark CIII BAFFLE want higher rpm three- four-bladed prop has shown cut noise level considerably Also used conjunction small addon tuned pipe passes test little no performance loss Continued page 127 14Model Aviation moddcajli TOUCH UP AIR BRUSH FOR DETAIL PAINTING OF AIRPLANE WINGS AND BOATS$4000 ARISTO TEX COVERING MATERIAL NEWI AND THE BEST YET CONTOURS BETTER WITH RICH COLORS BETTER STICK ING AND FUEL RESISTANT RED BLUE BLACK ORANGE WHITE GREEN ANlIQUE YELLOW 2 METER ROLL $720 TACHOMETER W/LED READ OUT FOR EAS FIELD READING CAfl00 ACCURATE ENGINE R PM IECE WOOD ING SET FOR HOBBYISTSA $30011 SOLDERING GUN 21 PIECE TOOL SET US SIZE SCREWDRIVERS PLUS PHILLIPS HEX AND WRENCH TYPES $700 4~4cz LE HANDS > WITH MAGNIFIER FOR EXTRA HELP IN HOLDING THOSE SMALL PARTS WHILE SOLDERING GLUING OR PAINTING MAGNIFIER LAMP WITH MULTI POSITION 3 1/ FLEXIBLE ARM 3 DIOPTER $3000 LENS FOR 4 liMES MAGNIFICATION Letters Editor Continued page 8 did pass out engines club nonclub members did realize loss until home passed out engines could controlled did inventory engines audience still present circumstance fortunate speaker club working resolve issue can see club can placed very difficult situation Current AMA insurance will cover type loss insurance avail able guest speakers homeowner s insur ance may want acquire insurance type occurrence minimum should institute controls meeting safeguard speakers assets addition give guest speaker some guidelines example case may want speaker hand out two engines time hope experience will help other AMA Chartered Clubs become aware another area prudence must prac ticed off flying site liability exposure everywhere John F Murray Pres Cape Ann RC Club Danvers MA Guest Editorial Continued page 14 3 OR 4 BLADE iIIIZiII~3K PROP does lead case got us back flying field club lost its field last summer due noise complaints local residents met residents administration field did noise-level tests decided aircraft too noisy could use field loss prompted investigation noise problem subsequent meeting same group demonstrated dramatic ally cut noise-emission levels residents agreed within confines 88 dBa would allowed use flying site again EditorAccompanying foregoing letter Joe Murray vice-president Radio Controlled Flying Club ronto Canada saying origi nally produced clubs news letter after about years study problem Later ran noise sym posium particlpation majority area clubs now general effort being made cut down overall noise levels has produced dramatic decrease number com plaints Joe pleased say writing advertisers mention read about Model Aviation WRAM Show/Myers Continued page 18 kinds products like see put forth Since talking about ducted fans might well take look example Nick Ziroli Models now offers kit F-4 RK-40 fan prototype flies well use 0S 46 ducted-fan engine Im sure would use Sullivan starter extension start en gine installation Curses foiled again Overall evaluation necessary nar row-band radios slowly beginning appear US manufacturers first answer call need offshore crowd now beginning follow suit Weve needed ever since new RC channels granted Im little puzzled delay introducing may idea 1991 receiver took some attention away fact 1991 right now far technical requirements concerned Safety Preston Continued page 24 Citabria passed safety inspection made very good friend Im suggesting friend deliberately overlooked things might otherwise have checked friends might assume things done right fact recently heard tale about qualifi cations inspectors models worth relating Although concerns incident club am mem ber wasnt field time following account related eyewitness beginner arrived field brand-new never-been-flown model club question has written check list such new models has designated certain members qualified inspectors occasion three qualified inspec tors spent about half hour scrutinizing model Apparently found noth ing out order model ap proved its first flight pilot flight clubs instructors After check engine operation instructor taxied out attempted takeoff model broke ground banked towards pit area whereupon pilot tried straighten out applying opposite aileron control increased bank towards pits model ended its short first flight striking trWsh can located rear pit area near fence separates pits Continued page 130 June1985127
Edition: Model Aviation - 1985/06
Page Numbers: 12, 14, 127
Noiseand Aircraft U Noise Committee RC Flying Club Toronto CASE STUDY Flying Field Saved Just about everyone concerned about pollution waste water air noise Flying sites have lost being lost will lost unless can come up some answers Once flying sites easy find around urban areas Now population growth increased activity hobby urban sprawl just about impossible find keep site within reasonable driving distance apparent continue enjoying hobby must learn quiet op eration Armed sound level meters set out find what up against Tests showed 40-sized engine its standard factory-supplied muffler meas ured seven meters distance meter off ground registered 86 93 dRa 60-sized engine its muffler registered 89 96 dRa choose seven meters distance meter off ground FM has spot check 105 dBa measured meter ground found too much room error slightest variance distance angie meter would give vastly different readings Also FAI check supposed made concrete blacktop fields dont have seven- one-meter measurement simple quick used successfully several European countries Exhaust gases major source noise what about prop noise What about intake noise What about con struction aircraft con tribute overall noise level much Lets look time Exhaust gases Mufflers quiet sound allowing gases slowly expand cool bigger muffler better works Most mufflers use large enough effective beyond 12000 rpm point gases being pushed through engine fast have little time expansion cooling leads us next item Prop noise 12000 rpm up prop noise becomes contributing factor degree people think Much sharp increase noise level evident higher rpm has often blamed prop case cars boats noisy higher rpm tests using electric motors swung props up 14000 rpm found although noise definitely fairly lowpitched noise does carry few hundred feet What about pitch Lets back up step two Noise least its nuisance value comprised two parts volume loudness pitch frequency example driving car 60mph window open produces noise level excess 90 dBa uncomfortable because low pitch other hand microphone feedback PA system unbearable because its high pitch good example short range prop noise four-stroke engines four-stroker flies can hear prop noise As soon few hundred feet away prop noise disap pears whereas engine noise continues Tatake aoise unable prove intake noise significant contrib uting factor until aircraft approaches 80 dBa noise level lower Aircraft coastructioa does have effect overall noise produced take dBa reading particular engine muffler mounted openstructured aircraft mount same combination aircraft solid sides foam-core wing dBa reading second will quieter Once again though drum effect fabricor heat-shrink-covered open-structured air craft low-pitched sound small contributor overall scene apparent continue enjoying hobby must learn quiet operation Thus far have discussed noise produced craft itself large contributing factor overall nuisance value given aircraft flown stands reason particularly noisy aircraft taken off full power throttled back half flown low close will cause less annoyance quieter theory aircraft flown far field full throttle high altitudes enlightening experience stand half-mile flying site note just aircraft offenders soon becomes obvious altitude large factor thinking about however recall last time observed full-size aircraft take off long distance see quite some time before sound heard Continued page 14 12 Model Aviation Hobby Lobbys Guest Editoria IQJ MINI-SERIES RICI HLRM1 320 Mini-Series F-4 PHANTOM$4400 High film strength lubricant increased power long engine life Detergents cut performance robbing varnish Highest quality ingredients insure top engine performance reliability Anti-foam additives prevent high RPM lean out Rust preventatives protect expensive engines TypeNitro 0/oLubricant4 Gal24 Gal64 Gal124 Gal FAI0%Synthetic$675$595$575$550 5s50/0Synthetic$775$695$675$650 Sc50/aCastor Oil$775$695$675$650 4-cycle70/aCastor/Syn$850$765$750$725 4-cycle150/0Castor/Syn$995$895$850$825 lOs100hSynthetic$895$795$750$725 lOc100/0Castor Oil$895$795$750$725 R/O120/oSyn/Castor$995$895$850$825 iSs150/0Synthetic$995$895$850$825 20c200/aCastor Oil$1395$1250$1200$1150 25s250/aSynthetic$1495$1350$1300$1250 4040%15 Syn-5 Castor$1995$1795$1750$1700 50S00/oSynthetic$2395$2100$2050$2000 60600/0Synthetic$2695$2400$2300$2200 HIN CONTINENTAL USA SHELDONS rs HOBBY SHOPMon Wed Fri & Sat M/C VISA 0 530 24-124 Gal 3157 Alum Rock AvenueThur 930-900 shipped via truck San Jose California 95127Sun 1200-500 UPS COD $165408 251-0787 ENGLISH FLAIR KITS Kits feature pre-cut Balsa & Ply Parts Formed Wire ware Furnished Spun Aluminum Cowl s Detailed plans show fully enclosed 4 stroke motor 4 models series See dealer write deatils Dealers inquire PUPPETEER $98g5 30-45 2 stroke motor 40-60 4 stroke motor VIA MORLEY ARCHOALE DR LOTTE NC 28210 happens aircraft attains higher alti tudes same true model aircraft tests showed noisy craft over 92 dBa could heard onehalf mile stayed below 200 ft ever 200 ft altitude isnt much dont expect everyone go around cutting grass props lets look some other solutions First needed goal Since 40-size smaller engines will pass 88 dBa level little no adjustment chose initial level would cut current average noise levels half Since exhaust prime cause noise attacked first using muffler works using two has work better quite dramatically Aircraft producing well excess 88 dRa reduced near 80 dBa Also method very little loss rpm second add-on muffler need fancy butane lighter refill can similar small can pipe sol dered epoxied end coupled primary muffler silicone tubing works fine 1/16-IN HOLES SIUCONE TUBE drawback foregoing its aesthetic value Its always hard enough hide muffler Scale ship can hide two Try small add-on made couple inches brass tubing 35 clamp small amount steel wool 00 size method will efficient double muffler has added ad vantage being adjustable drawback although can regulate dBa level produced amount steel wool used proportionate drop rpm Care should taken use too much steel wool very little needed rpm drops excess 1000 may cause overheating SOWER CAP Baffled mufflers Some fliers have cut mufflers half added divider middle make dual-chambered muffler once again efficient double-muffler system will get engines under 88 dRa mark CIII BAFFLE want higher rpm three- four-bladed prop has shown cut noise level considerably Also used conjunction small addon tuned pipe passes test little no performance loss Continued page 127 14Model Aviation moddcajli TOUCH UP AIR BRUSH FOR DETAIL PAINTING OF AIRPLANE WINGS AND BOATS$4000 ARISTO TEX COVERING MATERIAL NEWI AND THE BEST YET CONTOURS BETTER WITH RICH COLORS BETTER STICK ING AND FUEL RESISTANT RED BLUE BLACK ORANGE WHITE GREEN ANlIQUE YELLOW 2 METER ROLL $720 TACHOMETER W/LED READ OUT FOR EAS FIELD READING CAfl00 ACCURATE ENGINE R PM IECE WOOD ING SET FOR HOBBYISTSA $30011 SOLDERING GUN 21 PIECE TOOL SET US SIZE SCREWDRIVERS PLUS PHILLIPS HEX AND WRENCH TYPES $700 4~4cz LE HANDS > WITH MAGNIFIER FOR EXTRA HELP IN HOLDING THOSE SMALL PARTS WHILE SOLDERING GLUING OR PAINTING MAGNIFIER LAMP WITH MULTI POSITION 3 1/ FLEXIBLE ARM 3 DIOPTER $3000 LENS FOR 4 liMES MAGNIFICATION Letters Editor Continued page 8 did pass out engines club nonclub members did realize loss until home passed out engines could controlled did inventory engines audience still present circumstance fortunate speaker club working resolve issue can see club can placed very difficult situation Current AMA insurance will cover type loss insurance avail able guest speakers homeowner s insur ance may want acquire insurance type occurrence minimum should institute controls meeting safeguard speakers assets addition give guest speaker some guidelines example case may want speaker hand out two engines time hope experience will help other AMA Chartered Clubs become aware another area prudence must prac ticed off flying site liability exposure everywhere John F Murray Pres Cape Ann RC Club Danvers MA Guest Editorial Continued page 14 3 OR 4 BLADE iIIIZiII~3K PROP does lead case got us back flying field club lost its field last summer due noise complaints local residents met residents administration field did noise-level tests decided aircraft too noisy could use field loss prompted investigation noise problem subsequent meeting same group demonstrated dramatic ally cut noise-emission levels residents agreed within confines 88 dBa would allowed use flying site again EditorAccompanying foregoing letter Joe Murray vice-president Radio Controlled Flying Club ronto Canada saying origi nally produced clubs news letter after about years study problem Later ran noise sym posium particlpation majority area clubs now general effort being made cut down overall noise levels has produced dramatic decrease number com plaints Joe pleased say writing advertisers mention read about Model Aviation WRAM Show/Myers Continued page 18 kinds products like see put forth Since talking about ducted fans might well take look example Nick Ziroli Models now offers kit F-4 RK-40 fan prototype flies well use 0S 46 ducted-fan engine Im sure would use Sullivan starter extension start en gine installation Curses foiled again Overall evaluation necessary nar row-band radios slowly beginning appear US manufacturers first answer call need offshore crowd now beginning follow suit Weve needed ever since new RC channels granted Im little puzzled delay introducing may idea 1991 receiver took some attention away fact 1991 right now far technical requirements concerned Safety Preston Continued page 24 Citabria passed safety inspection made very good friend Im suggesting friend deliberately overlooked things might otherwise have checked friends might assume things done right fact recently heard tale about qualifi cations inspectors models worth relating Although concerns incident club am mem ber wasnt field time following account related eyewitness beginner arrived field brand-new never-been-flown model club question has written check list such new models has designated certain members qualified inspectors occasion three qualified inspec tors spent about half hour scrutinizing model Apparently found noth ing out order model ap proved its first flight pilot flight clubs instructors After check engine operation instructor taxied out attempted takeoff model broke ground banked towards pit area whereupon pilot tried straighten out applying opposite aileron control increased bank towards pits model ended its short first flight striking trWsh can located rear pit area near fence separates pits Continued page 130 June1985127
Edition: Model Aviation - 1985/06
Page Numbers: 12, 14, 127
Noiseand Aircraft U Noise Committee RC Flying Club Toronto CASE STUDY Flying Field Saved Just about everyone concerned about pollution waste water air noise Flying sites have lost being lost will lost unless can come up some answers Once flying sites easy find around urban areas Now population growth increased activity hobby urban sprawl just about impossible find keep site within reasonable driving distance apparent continue enjoying hobby must learn quiet op eration Armed sound level meters set out find what up against Tests showed 40-sized engine its standard factory-supplied muffler meas ured seven meters distance meter off ground registered 86 93 dRa 60-sized engine its muffler registered 89 96 dRa choose seven meters distance meter off ground FM has spot check 105 dBa measured meter ground found too much room error slightest variance distance angie meter would give vastly different readings Also FAI check supposed made concrete blacktop fields dont have seven- one-meter measurement simple quick used successfully several European countries Exhaust gases major source noise what about prop noise What about intake noise What about con struction aircraft con tribute overall noise level much Lets look time Exhaust gases Mufflers quiet sound allowing gases slowly expand cool bigger muffler better works Most mufflers use large enough effective beyond 12000 rpm point gases being pushed through engine fast have little time expansion cooling leads us next item Prop noise 12000 rpm up prop noise becomes contributing factor degree people think Much sharp increase noise level evident higher rpm has often blamed prop case cars boats noisy higher rpm tests using electric motors swung props up 14000 rpm found although noise definitely fairly lowpitched noise does carry few hundred feet What about pitch Lets back up step two Noise least its nuisance value comprised two parts volume loudness pitch frequency example driving car 60mph window open produces noise level excess 90 dBa uncomfortable because low pitch other hand microphone feedback PA system unbearable because its high pitch good example short range prop noise four-stroke engines four-stroker flies can hear prop noise As soon few hundred feet away prop noise disap pears whereas engine noise continues Tatake aoise unable prove intake noise significant contrib uting factor until aircraft approaches 80 dBa noise level lower Aircraft coastructioa does have effect overall noise produced take dBa reading particular engine muffler mounted openstructured aircraft mount same combination aircraft solid sides foam-core wing dBa reading second will quieter Once again though drum effect fabricor heat-shrink-covered open-structured air craft low-pitched sound small contributor overall scene apparent continue enjoying hobby must learn quiet operation Thus far have discussed noise produced craft itself large contributing factor overall nuisance value given aircraft flown stands reason particularly noisy aircraft taken off full power throttled back half flown low close will cause less annoyance quieter theory aircraft flown far field full throttle high altitudes enlightening experience stand half-mile flying site note just aircraft offenders soon becomes obvious altitude large factor thinking about however recall last time observed full-size aircraft take off long distance see quite some time before sound heard Continued page 14 12 Model Aviation Hobby Lobbys Guest Editoria IQJ MINI-SERIES RICI HLRM1 320 Mini-Series F-4 PHANTOM$4400 High film strength lubricant increased power long engine life Detergents cut performance robbing varnish Highest quality ingredients insure top engine performance reliability Anti-foam additives prevent high RPM lean out Rust preventatives protect expensive engines TypeNitro 0/oLubricant4 Gal24 Gal64 Gal124 Gal FAI0%Synthetic$675$595$575$550 5s50/0Synthetic$775$695$675$650 Sc50/aCastor Oil$775$695$675$650 4-cycle70/aCastor/Syn$850$765$750$725 4-cycle150/0Castor/Syn$995$895$850$825 lOs100hSynthetic$895$795$750$725 lOc100/0Castor Oil$895$795$750$725 R/O120/oSyn/Castor$995$895$850$825 iSs150/0Synthetic$995$895$850$825 20c200/aCastor Oil$1395$1250$1200$1150 25s250/aSynthetic$1495$1350$1300$1250 4040%15 Syn-5 Castor$1995$1795$1750$1700 50S00/oSynthetic$2395$2100$2050$2000 60600/0Synthetic$2695$2400$2300$2200 HIN CONTINENTAL USA SHELDONS rs HOBBY SHOPMon Wed Fri & Sat M/C VISA 0 530 24-124 Gal 3157 Alum Rock AvenueThur 930-900 shipped via truck San Jose California 95127Sun 1200-500 UPS COD $165408 251-0787 ENGLISH FLAIR KITS Kits feature pre-cut Balsa & Ply Parts Formed Wire ware Furnished Spun Aluminum Cowl s Detailed plans show fully enclosed 4 stroke motor 4 models series See dealer write deatils Dealers inquire PUPPETEER $98g5 30-45 2 stroke motor 40-60 4 stroke motor VIA MORLEY ARCHOALE DR LOTTE NC 28210 happens aircraft attains higher alti tudes same true model aircraft tests showed noisy craft over 92 dBa could heard onehalf mile stayed below 200 ft ever 200 ft altitude isnt much dont expect everyone go around cutting grass props lets look some other solutions First needed goal Since 40-size smaller engines will pass 88 dBa level little no adjustment chose initial level would cut current average noise levels half Since exhaust prime cause noise attacked first using muffler works using two has work better quite dramatically Aircraft producing well excess 88 dRa reduced near 80 dBa Also method very little loss rpm second add-on muffler need fancy butane lighter refill can similar small can pipe sol dered epoxied end coupled primary muffler silicone tubing works fine 1/16-IN HOLES SIUCONE TUBE drawback foregoing its aesthetic value Its always hard enough hide muffler Scale ship can hide two Try small add-on made couple inches brass tubing 35 clamp small amount steel wool 00 size method will efficient double muffler has added ad vantage being adjustable drawback although can regulate dBa level produced amount steel wool used proportionate drop rpm Care should taken use too much steel wool very little needed rpm drops excess 1000 may cause overheating SOWER CAP Baffled mufflers Some fliers have cut mufflers half added divider middle make dual-chambered muffler once again efficient double-muffler system will get engines under 88 dRa mark CIII BAFFLE want higher rpm three- four-bladed prop has shown cut noise level considerably Also used conjunction small addon tuned pipe passes test little no performance loss Continued page 127 14Model Aviation moddcajli TOUCH UP AIR BRUSH FOR DETAIL PAINTING OF AIRPLANE WINGS AND BOATS$4000 ARISTO TEX COVERING MATERIAL NEWI AND THE BEST YET CONTOURS BETTER WITH RICH COLORS BETTER STICK ING AND FUEL RESISTANT RED BLUE BLACK ORANGE WHITE GREEN ANlIQUE YELLOW 2 METER ROLL $720 TACHOMETER W/LED READ OUT FOR EAS FIELD READING CAfl00 ACCURATE ENGINE R PM IECE WOOD ING SET FOR HOBBYISTSA $30011 SOLDERING GUN 21 PIECE TOOL SET US SIZE SCREWDRIVERS PLUS PHILLIPS HEX AND WRENCH TYPES $700 4~4cz LE HANDS > WITH MAGNIFIER FOR EXTRA HELP IN HOLDING THOSE SMALL PARTS WHILE SOLDERING GLUING OR PAINTING MAGNIFIER LAMP WITH MULTI POSITION 3 1/ FLEXIBLE ARM 3 DIOPTER $3000 LENS FOR 4 liMES MAGNIFICATION Letters Editor Continued page 8 did pass out engines club nonclub members did realize loss until home passed out engines could controlled did inventory engines audience still present circumstance fortunate speaker club working resolve issue can see club can placed very difficult situation Current AMA insurance will cover type loss insurance avail able guest speakers homeowner s insur ance may want acquire insurance type occurrence minimum should institute controls meeting safeguard speakers assets addition give guest speaker some guidelines example case may want speaker hand out two engines time hope experience will help other AMA Chartered Clubs become aware another area prudence must prac ticed off flying site liability exposure everywhere John F Murray Pres Cape Ann RC Club Danvers MA Guest Editorial Continued page 14 3 OR 4 BLADE iIIIZiII~3K PROP does lead case got us back flying field club lost its field last summer due noise complaints local residents met residents administration field did noise-level tests decided aircraft too noisy could use field loss prompted investigation noise problem subsequent meeting same group demonstrated dramatic ally cut noise-emission levels residents agreed within confines 88 dBa would allowed use flying site again EditorAccompanying foregoing letter Joe Murray vice-president Radio Controlled Flying Club ronto Canada saying origi nally produced clubs news letter after about years study problem Later ran noise sym posium particlpation majority area clubs now general effort being made cut down overall noise levels has produced dramatic decrease number com plaints Joe pleased say writing advertisers mention read about Model Aviation WRAM Show/Myers Continued page 18 kinds products like see put forth Since talking about ducted fans might well take look example Nick Ziroli Models now offers kit F-4 RK-40 fan prototype flies well use 0S 46 ducted-fan engine Im sure would use Sullivan starter extension start en gine installation Curses foiled again Overall evaluation necessary nar row-band radios slowly beginning appear US manufacturers first answer call need offshore crowd now beginning follow suit Weve needed ever since new RC channels granted Im little puzzled delay introducing may idea 1991 receiver took some attention away fact 1991 right now far technical requirements concerned Safety Preston Continued page 24 Citabria passed safety inspection made very good friend Im suggesting friend deliberately overlooked things might otherwise have checked friends might assume things done right fact recently heard tale about qualifi cations inspectors models worth relating Although concerns incident club am mem ber wasnt field time following account related eyewitness beginner arrived field brand-new never-been-flown model club question has written check list such new models has designated certain members qualified inspectors occasion three qualified inspec tors spent about half hour scrutinizing model Apparently found noth ing out order model ap proved its first flight pilot flight clubs instructors After check engine operation instructor taxied out attempted takeoff model broke ground banked towards pit area whereupon pilot tried straighten out applying opposite aileron control increased bank towards pits model ended its short first flight striking trWsh can located rear pit area near fence separates pits Continued page 130 June1985127