George M Mye Radio Thchnque 70 Froebllch Farm Rd Hkksvlfle NY 11801 ABSTRACT More Alaska trip Lanier Laser GeeBee floats Porta-Sol kit DFS Sailplane SAID February 1989 column would take Lanier Seabird trip Alaska turned out too bulky made last-minute decision take Lanier Laser instead Laser stored neatly out way ceiling van bungees Bun gees long cloth-covered rubberbands about 5/~ in diameter fitted hooks ends Im hack New York again after wonderful summer Alaska smarter things did preparing trip remove screws holding terior moldings vans windows time slip swivel hanger meant hang ing pictures before putting screw back gave little wire loops over van taching bungees drive van know set pencil down somewhere will go corner van within next few miles bungees use better things will stay place Stock #4SPH B&R Specialty Hardware PO Box 0095 Baldwin NY 11510 Find bubble cards hanging picture hardware section clipped off lug containing outside hole neater appear ance Lanier Laser constructed plasticsheeted foam-cored wing horizontal tail balsa fin control surfaces styrene shell over plywood fuselage weighs 6 lb 6 oz radio engine installed minus fuel landing gear Length 505 wingspan 59 wing area 600 sq Splash some Hobbypoxy plywood have almost-waterproof plane engine trusty old 1980 05 60 FSR pump mounted Edson adjustable metal mount turn firewall mounted way four Davis ISO-Mount vibration isola tors can see photo installation page 79 Model Aviation June 89 engine fully cowled has K&B air cleaner its Perry carburetor keeps wa ter out engine Besides plenty dust Alaska turns 12 x 6 propeller hold airplane engine running see engine moving around inside cowl ing dont feel much vibration air frame made sound-level check ground nine feet read 88 dBA stan dard OS muffler engine dB meter peaked 73 dBA during full-speed flyby Palmer AK plane about 10 ft Out 10 ft up theory will radiate less noise less damage airplane its contentswhen isolate engine airframe practice plane sounds quieter other 60-powered ships plenty fast Ketchikan AK first stop Alaska has no flat land RC flying done water brought along 33-in Gee Bee floats 67% fuselage length spaced 13 apart 40% float length top floats 1 below tip prop floats tached airplane two aluminum straps Left Grandpa starls em out early Kevin Myers Georges youngest grandson prepares board Grandpas Lanier Laser GeeBee 33-in floats Right Triton Models -scale DFS Sailplane Triton located Kotzebue Alaska thats Address column Left Do transport models van George installed bunch swivel hangers van raves about convenience fastening bungee cords em Right Lanier Lasers wheel pant mounted help Goldberg Models nose wheel steering tiller arm screwed interior pant shell Minor surgery plastic tiller required Neat Easy Convenient info column 36 Model Aviation supplied Lanier kit landing gear bolted fuselage tal four 1A x 20 Du-Bro nylon bolts water rudder right-hand float driven pushrod control horn air rudder Eight pieces 1A6 x 34 x 4-in dural angles sand wiched four mounting tabs Gee Bee floats keep rocking last two ad ditions made Bob Andrew Ketchi kan Rainbirds RC Club complete assembly adds 1 lb 9 oz plane flight drag floats makes air plane neutral ie flies inverted Down elevator used Gee Bees because because installation simple make because work Larger floats per advice Floats & Fittings Ed Westwood October 1989 MA would easier beginners handle water cost additional weight drag Im ginner can take choice Laser has flown off both rough smooth water wind combination described above works use full Up elevator feed power gradually getting up step takeoff otherwise prop eats lot water make water landings step because am quite sure model will nose over dont flying rough water take off land parallel wave crests checked out pontoon installation swimming pool home before making perma nent Laser floats fresh water about 1 pontoons above surface along length fuel tank full floats little tail-low tank empty either case push wing tip down water plane pops up onto floats again soon release wing push prop tip un der water itpops out again too long fu selage less J0 nose-down water also brought along pair Dave Browns sponge-tired wheels use wheel pants provided kit flying off pavement larger Du-Bro lightweight tires flying off turf might interested mounted wheel pants Installation begins Du-Bro axle HalIco-type bent aluminum strap Next drilled axle-size hole through wheel pants per kit instructions Now cute part installed Goldberg Continued page 145 CARBON FIBER LAMINATES Aerospace Composite Products offers variety rigid carbon fiber/epoxy sheets add stiffness almost material- fiberglass foam bal sawood laminates can used reinforce foam wings leading trailing edges wing spars Carbon Fiber bonds easily slow setting cyanoacrylates 5-minute epoxies laminate can stripped narrower widths CL-i 007 thick 1x48-$50O 1x72-$7OO CL-2 014 thick 1x48-$8OO 1x72-$11O0 Send SASE information additional sizes products Add $300 shipping handling Calif residents add 6% tax Overseas orders odd 15%-Order COD send check money order I- IThe source lightweight materials PO Box 16621 Dept M Irvine CA 92714 714 250-1107 h. January 1990 37 New Model P-1K Porta-Sol portable butanefueled heat wand can used soldering hof-krsife cutting making on-field repairs MonoKote etc George loves gives comments ordering Info column executing first maneuvers Aileron throw may need adjusted recommend somewhat throw lower power less high-priced systems plans show average throws throw easily changed adjusting position screw-on nylon pieces threaded horns flown fairly aggressively Gold Fire-equipped version turned flight times four 4 minutes Installed fer rite 15 plane flew 4/2-to-five-minute runs Whichever power system youre us ing flights can stretched over seven minutes gentler handling air proper use speed control Good Luck Skyvolt hope have much fun quiet flying hours Ive Please dont hesitate send comments ques tions Id also welcome photos fin ished beauty closing want acknowl edge local modeler Bob Clauss suggest ing models name responding advertisers mention read about Model Aviation Continued page 37 tiller bar normally used nose-wheel steering outboard side wheel inside pant attached pant way #2 sheet metal screws type normally used mounting servos Cutting off excess screw length completed installation Since wanted tiller arm flat against wheel pant drill new hole through tiller bar plastic after pushing out metal wheel collar bore plastic til ler put setscrew bottom can easily get Put wheel collar back place its setscrew hole matching new hole youve just drilled tiller Finally file flat axle wheel pant wont fall off immediately after attaching screw becomes little loose New Porta-Sol kit pocket-size Porta-Sol butane-fueled flameless soldering iron Radio Technique February 88 issue MA page 38 proved very handy tool trip used sorts things like installing connec tort shrinking shrink-tubing insulators putting holes plastic etc point remem ber using solder wire back coil Quadra someone field somewhere fact burns cigarette-lighter Butane can lit sparker built its cap virtu ally windproof makes usable almost anywhere Porta-Sol now offers better versatile kit P-lK containing black Porta-Sol four kinds tools tip cleaner hot stand handy box measuring 15 x 3 x 9 like neat kits put useful tools easily stored pack ages Ive added P-tK van new kit features tools plastic retaining screws permit remove/install tools hot interchangeable older orange model al lowed cool first new internally heated tools heat range equivalent electric sol dering irons 10 60 watts very useful de signs Tools include I Standard %2 tip same size older model Other tip sizes 040 %2 Y6 available $899 2 Hot knife Integral design much thicker X-Acto blade sharp fine cut ting plastic sheet sailcloth etc 3 Pencil torch tiny flame fine soldering etc 4 Hot air gun 3R2-diameter source hot air use shrink tubing taking small wrinkles out MonoKote etc really like tool cause tip small Y16 dia x 1 long has no exposed flame can get down inside things dont touch tip sliding shutter anything after have lit fire As before kit made available ser January 1990 145 Radio Technique/Myers THE TAILGEAR SPJtT PASTERN SPORTSCALE Pat Pend flROVE GROUND RANDLfl4G ABSORB SNK TO AIRFRAME AND SERVO DIFFERERTIAL TEROW FOUSIRLE MAT NE INSTALLED IN Mt EflSTIEO BRACKET BRACKET INTERNAL FuSELAGE MOUNT EAST INSTALLATION EASILY ADJUSTABLE NONBINDING COMPLETE INSTALLATION FACEAGE* Mt 1d Q SMALL iO 1AEDIUM6O LABOE 120 TO CNiDER send ns ~ss andEFLigit Industries size desired sith 610 Th16 Woodnore Lane P&a INCLUDER Chattanooga TN 3Thfl FW4 B4OI FREE CATALOG Best 40 Ever 4 Channel nch Span -Symmetrical Wing 25 - 40 Engine 3 3-1/2 lbs Superior Performance Available Favorite Hobby ShopTi4ewoLeL Guaranteed Satisfaction~- 3925-C SE 45th Court IdE/tsiIuaIhIflAOcala FL 32671 S IA41eL FVI44~d lEE 6943531 FULL BODY PILOT KIT DARNED GOOD AIRMEN Lightest pilots available Lifelike vinyl latex rubber cap goggles full templates easy instruc Build Sportsman Barnstormer Full Body Bust V Contains pilot head hands boots helmet lions Easy assemble finish Some simple sewing required Fully BUST PILOT KITpositionable tool Pta Contains pilot head helmet apart cap goggles#206-A sca895 L#205hi jacket Easy assemble finishA scee995 Per-#204- sea1095 #108-1A scaleNEW#203-A scae695 #1061/ scale #l05-/n scale795 scale895* some scale 1495 mpie aew ng equ Gd JET PILOT KIT Pilot has molded jet helmet Contains face mask oxygen hose Extreme ly Realistic Weighs less V2 oz Pea #308-A scale 595 #307-V scale 695 ORDERING INSTRUCTIONS See dealer first order direct Add $100 shipping NYS residents add 7% lax Send check money order CODS OK Send $100 catalog See Dealer add Dollar direct otder handling vice modelers friend Les Shine doing business Bentley Electronics 106 Wedgewood Drive Hauppauge NY 11788 telephone 1800/634-6306 also available through SR Bat teries P-IK fuel Stock # 50A18107 can shipped air $5499 Fuel can purchased cigar counters shipped surface UPS Ask Colibri butane 34 fi oz Stock # 50A18106 $399 Scale Sailplane kit visiting Kotzebue AK tiny village above Arctic Cir cle right Bering Sea 65 miles Si beria made acquaintance Greg Harding doing business Triton Models Box 1157 Kot zebue AK 99752 telephone 1-707/442-2617 Kotzebue just about out-of-the-way place imaginable find model manu facturer time Greg offering nice fiberglass-bodied 4-scale model 1937 DFS Reicher gull-winged sailplane former ly flown Hanna Reicher Hanna Germanys foremost aviatrix es put name history books flew Focke-WuIf twin-rotor helicopter side Olympic Stadium Berlin about 1939 Scale enthusiasts might want give Greg call Time Kotzebue two hours earlier Pa cific Standard Time keep mind call ie 800 am New York 300 am Kotzebue Propeller Noise Continued page 41 ities Although 12 x 6 propeller has higher peak efficiency occurs lower flight speeds Such propeller would ef ficient near takeoff conditions perform poorly high flight speeds Equally impor tant assuming torque loading ma jor cause propeller noise props efficient high speeds will provide re duced noise levels no compromise performance Torque noise Several other findings impli cate torque loading dominant compo nent propeller noise Figure 4 shows plot SPL blade-passing fre quency BPF measured lab about 90 tant rotational speed Also shown curve generated using ac cepted empirical theory torque noise has shown correlate very closely experimental data Since havior SPL shaft power follows expected behavior torque noise can reasonably conjecture measured noise source fact torque noise broader view data obtained examining total acoustic power sound power radiated measurement de rived integration acoustic pres sure over space sound power can compared relation between sound power shaft power classical theory propeller noise developed years ago researcher named Gutin Figure 5 shows comparison 10500 rpm simulated flight speed 100 ft/sec Note agreement tween acoustic power data Gutin theory quite close correlation tween results shown Fig ure 4 view complications associ ated combining sufficient measure ments integrating data obtain acoustic power such consistency between two sets data unexpected Both re sults point torque-related noise leading element propeller sound reader will recall propeller efficiency low work engine must used overcome torque propeller rather produce thrust plot propulsive efficiency against sound power several different props assuming acoustic power derived primarily torque loads lat ter would rise propeller efficiency de clined Due variability thrustrelated noise however such plot would meaningful thrust held constant As shown plot Figure 6 noise due thrust held constant acoustic output varies propeller diameter ac cording propeller efficiency further corroborates dominant noise mechanism sound due torque loading propeller blades thrust-related noise dominant sound power vari ation Figure 6 would nearly con stant point can see constant thrust does lead constant noise Continued page 150 4 Championship Design Outstanding4 Strong & Stable New Combat/Sport4 FastEasyAssembly Plane4 High Performance Includes Complete Hardware ine Included Belicrank outs s 0 Hinges s & Nuts $100 catalog Precision Foam Wing Corescontrol-line combat specialties Dealer & Distributor inquiries Welcome 760 Waltonville Road 1-lummelatown PA 17036 66-3810 148 Model Aviation
Edition: Model Aviation - 1990/01
Page Numbers: 36, 37, 145, 148
George M Mye Radio Thchnque 70 Froebllch Farm Rd Hkksvlfle NY 11801 ABSTRACT More Alaska trip Lanier Laser GeeBee floats Porta-Sol kit DFS Sailplane SAID February 1989 column would take Lanier Seabird trip Alaska turned out too bulky made last-minute decision take Lanier Laser instead Laser stored neatly out way ceiling van bungees Bun gees long cloth-covered rubberbands about 5/~ in diameter fitted hooks ends Im hack New York again after wonderful summer Alaska smarter things did preparing trip remove screws holding terior moldings vans windows time slip swivel hanger meant hang ing pictures before putting screw back gave little wire loops over van taching bungees drive van know set pencil down somewhere will go corner van within next few miles bungees use better things will stay place Stock #4SPH B&R Specialty Hardware PO Box 0095 Baldwin NY 11510 Find bubble cards hanging picture hardware section clipped off lug containing outside hole neater appear ance Lanier Laser constructed plasticsheeted foam-cored wing horizontal tail balsa fin control surfaces styrene shell over plywood fuselage weighs 6 lb 6 oz radio engine installed minus fuel landing gear Length 505 wingspan 59 wing area 600 sq Splash some Hobbypoxy plywood have almost-waterproof plane engine trusty old 1980 05 60 FSR pump mounted Edson adjustable metal mount turn firewall mounted way four Davis ISO-Mount vibration isola tors can see photo installation page 79 Model Aviation June 89 engine fully cowled has K&B air cleaner its Perry carburetor keeps wa ter out engine Besides plenty dust Alaska turns 12 x 6 propeller hold airplane engine running see engine moving around inside cowl ing dont feel much vibration air frame made sound-level check ground nine feet read 88 dBA stan dard OS muffler engine dB meter peaked 73 dBA during full-speed flyby Palmer AK plane about 10 ft Out 10 ft up theory will radiate less noise less damage airplane its contentswhen isolate engine airframe practice plane sounds quieter other 60-powered ships plenty fast Ketchikan AK first stop Alaska has no flat land RC flying done water brought along 33-in Gee Bee floats 67% fuselage length spaced 13 apart 40% float length top floats 1 below tip prop floats tached airplane two aluminum straps Left Grandpa starls em out early Kevin Myers Georges youngest grandson prepares board Grandpas Lanier Laser GeeBee 33-in floats Right Triton Models -scale DFS Sailplane Triton located Kotzebue Alaska thats Address column Left Do transport models van George installed bunch swivel hangers van raves about convenience fastening bungee cords em Right Lanier Lasers wheel pant mounted help Goldberg Models nose wheel steering tiller arm screwed interior pant shell Minor surgery plastic tiller required Neat Easy Convenient info column 36 Model Aviation supplied Lanier kit landing gear bolted fuselage tal four 1A x 20 Du-Bro nylon bolts water rudder right-hand float driven pushrod control horn air rudder Eight pieces 1A6 x 34 x 4-in dural angles sand wiched four mounting tabs Gee Bee floats keep rocking last two ad ditions made Bob Andrew Ketchi kan Rainbirds RC Club complete assembly adds 1 lb 9 oz plane flight drag floats makes air plane neutral ie flies inverted Down elevator used Gee Bees because because installation simple make because work Larger floats per advice Floats & Fittings Ed Westwood October 1989 MA would easier beginners handle water cost additional weight drag Im ginner can take choice Laser has flown off both rough smooth water wind combination described above works use full Up elevator feed power gradually getting up step takeoff otherwise prop eats lot water make water landings step because am quite sure model will nose over dont flying rough water take off land parallel wave crests checked out pontoon installation swimming pool home before making perma nent Laser floats fresh water about 1 pontoons above surface along length fuel tank full floats little tail-low tank empty either case push wing tip down water plane pops up onto floats again soon release wing push prop tip un der water itpops out again too long fu selage less J0 nose-down water also brought along pair Dave Browns sponge-tired wheels use wheel pants provided kit flying off pavement larger Du-Bro lightweight tires flying off turf might interested mounted wheel pants Installation begins Du-Bro axle HalIco-type bent aluminum strap Next drilled axle-size hole through wheel pants per kit instructions Now cute part installed Goldberg Continued page 145 CARBON FIBER LAMINATES Aerospace Composite Products offers variety rigid carbon fiber/epoxy sheets add stiffness almost material- fiberglass foam bal sawood laminates can used reinforce foam wings leading trailing edges wing spars Carbon Fiber bonds easily slow setting cyanoacrylates 5-minute epoxies laminate can stripped narrower widths CL-i 007 thick 1x48-$50O 1x72-$7OO CL-2 014 thick 1x48-$8OO 1x72-$11O0 Send SASE information additional sizes products Add $300 shipping handling Calif residents add 6% tax Overseas orders odd 15%-Order COD send check money order I- IThe source lightweight materials PO Box 16621 Dept M Irvine CA 92714 714 250-1107 h. January 1990 37 New Model P-1K Porta-Sol portable butanefueled heat wand can used soldering hof-krsife cutting making on-field repairs MonoKote etc George loves gives comments ordering Info column executing first maneuvers Aileron throw may need adjusted recommend somewhat throw lower power less high-priced systems plans show average throws throw easily changed adjusting position screw-on nylon pieces threaded horns flown fairly aggressively Gold Fire-equipped version turned flight times four 4 minutes Installed fer rite 15 plane flew 4/2-to-five-minute runs Whichever power system youre us ing flights can stretched over seven minutes gentler handling air proper use speed control Good Luck Skyvolt hope have much fun quiet flying hours Ive Please dont hesitate send comments ques tions Id also welcome photos fin ished beauty closing want acknowl edge local modeler Bob Clauss suggest ing models name responding advertisers mention read about Model Aviation Continued page 37 tiller bar normally used nose-wheel steering outboard side wheel inside pant attached pant way #2 sheet metal screws type normally used mounting servos Cutting off excess screw length completed installation Since wanted tiller arm flat against wheel pant drill new hole through tiller bar plastic after pushing out metal wheel collar bore plastic til ler put setscrew bottom can easily get Put wheel collar back place its setscrew hole matching new hole youve just drilled tiller Finally file flat axle wheel pant wont fall off immediately after attaching screw becomes little loose New Porta-Sol kit pocket-size Porta-Sol butane-fueled flameless soldering iron Radio Technique February 88 issue MA page 38 proved very handy tool trip used sorts things like installing connec tort shrinking shrink-tubing insulators putting holes plastic etc point remem ber using solder wire back coil Quadra someone field somewhere fact burns cigarette-lighter Butane can lit sparker built its cap virtu ally windproof makes usable almost anywhere Porta-Sol now offers better versatile kit P-lK containing black Porta-Sol four kinds tools tip cleaner hot stand handy box measuring 15 x 3 x 9 like neat kits put useful tools easily stored pack ages Ive added P-tK van new kit features tools plastic retaining screws permit remove/install tools hot interchangeable older orange model al lowed cool first new internally heated tools heat range equivalent electric sol dering irons 10 60 watts very useful de signs Tools include I Standard %2 tip same size older model Other tip sizes 040 %2 Y6 available $899 2 Hot knife Integral design much thicker X-Acto blade sharp fine cut ting plastic sheet sailcloth etc 3 Pencil torch tiny flame fine soldering etc 4 Hot air gun 3R2-diameter source hot air use shrink tubing taking small wrinkles out MonoKote etc really like tool cause tip small Y16 dia x 1 long has no exposed flame can get down inside things dont touch tip sliding shutter anything after have lit fire As before kit made available ser January 1990 145 Radio Technique/Myers THE TAILGEAR SPJtT PASTERN SPORTSCALE Pat Pend flROVE GROUND RANDLfl4G ABSORB SNK TO AIRFRAME AND SERVO DIFFERERTIAL TEROW FOUSIRLE MAT NE INSTALLED IN Mt EflSTIEO BRACKET BRACKET INTERNAL FuSELAGE MOUNT EAST INSTALLATION EASILY ADJUSTABLE NONBINDING COMPLETE INSTALLATION FACEAGE* Mt 1d Q SMALL iO 1AEDIUM6O LABOE 120 TO CNiDER send ns ~ss andEFLigit Industries size desired sith 610 Th16 Woodnore Lane P&a INCLUDER Chattanooga TN 3Thfl FW4 B4OI FREE CATALOG Best 40 Ever 4 Channel nch Span -Symmetrical Wing 25 - 40 Engine 3 3-1/2 lbs Superior Performance Available Favorite Hobby ShopTi4ewoLeL Guaranteed Satisfaction~- 3925-C SE 45th Court IdE/tsiIuaIhIflAOcala FL 32671 S IA41eL FVI44~d lEE 6943531 FULL BODY PILOT KIT DARNED GOOD AIRMEN Lightest pilots available Lifelike vinyl latex rubber cap goggles full templates easy instruc Build Sportsman Barnstormer Full Body Bust V Contains pilot head hands boots helmet lions Easy assemble finish Some simple sewing required Fully BUST PILOT KITpositionable tool Pta Contains pilot head helmet apart cap goggles#206-A sca895 L#205hi jacket Easy assemble finishA scee995 Per-#204- sea1095 #108-1A scaleNEW#203-A scae695 #1061/ scale #l05-/n scale795 scale895* some scale 1495 mpie aew ng equ Gd JET PILOT KIT Pilot has molded jet helmet Contains face mask oxygen hose Extreme ly Realistic Weighs less V2 oz Pea #308-A scale 595 #307-V scale 695 ORDERING INSTRUCTIONS See dealer first order direct Add $100 shipping NYS residents add 7% lax Send check money order CODS OK Send $100 catalog See Dealer add Dollar direct otder handling vice modelers friend Les Shine doing business Bentley Electronics 106 Wedgewood Drive Hauppauge NY 11788 telephone 1800/634-6306 also available through SR Bat teries P-IK fuel Stock # 50A18107 can shipped air $5499 Fuel can purchased cigar counters shipped surface UPS Ask Colibri butane 34 fi oz Stock # 50A18106 $399 Scale Sailplane kit visiting Kotzebue AK tiny village above Arctic Cir cle right Bering Sea 65 miles Si beria made acquaintance Greg Harding doing business Triton Models Box 1157 Kot zebue AK 99752 telephone 1-707/442-2617 Kotzebue just about out-of-the-way place imaginable find model manu facturer time Greg offering nice fiberglass-bodied 4-scale model 1937 DFS Reicher gull-winged sailplane former ly flown Hanna Reicher Hanna Germanys foremost aviatrix es put name history books flew Focke-WuIf twin-rotor helicopter side Olympic Stadium Berlin about 1939 Scale enthusiasts might want give Greg call Time Kotzebue two hours earlier Pa cific Standard Time keep mind call ie 800 am New York 300 am Kotzebue Propeller Noise Continued page 41 ities Although 12 x 6 propeller has higher peak efficiency occurs lower flight speeds Such propeller would ef ficient near takeoff conditions perform poorly high flight speeds Equally impor tant assuming torque loading ma jor cause propeller noise props efficient high speeds will provide re duced noise levels no compromise performance Torque noise Several other findings impli cate torque loading dominant compo nent propeller noise Figure 4 shows plot SPL blade-passing fre quency BPF measured lab about 90 tant rotational speed Also shown curve generated using ac cepted empirical theory torque noise has shown correlate very closely experimental data Since havior SPL shaft power follows expected behavior torque noise can reasonably conjecture measured noise source fact torque noise broader view data obtained examining total acoustic power sound power radiated measurement de rived integration acoustic pres sure over space sound power can compared relation between sound power shaft power classical theory propeller noise developed years ago researcher named Gutin Figure 5 shows comparison 10500 rpm simulated flight speed 100 ft/sec Note agreement tween acoustic power data Gutin theory quite close correlation tween results shown Fig ure 4 view complications associ ated combining sufficient measure ments integrating data obtain acoustic power such consistency between two sets data unexpected Both re sults point torque-related noise leading element propeller sound reader will recall propeller efficiency low work engine must used overcome torque propeller rather produce thrust plot propulsive efficiency against sound power several different props assuming acoustic power derived primarily torque loads lat ter would rise propeller efficiency de clined Due variability thrustrelated noise however such plot would meaningful thrust held constant As shown plot Figure 6 noise due thrust held constant acoustic output varies propeller diameter ac cording propeller efficiency further corroborates dominant noise mechanism sound due torque loading propeller blades thrust-related noise dominant sound power vari ation Figure 6 would nearly con stant point can see constant thrust does lead constant noise Continued page 150 4 Championship Design Outstanding4 Strong & Stable New Combat/Sport4 FastEasyAssembly Plane4 High Performance Includes Complete Hardware ine Included Belicrank outs s 0 Hinges s & Nuts $100 catalog Precision Foam Wing Corescontrol-line combat specialties Dealer & Distributor inquiries Welcome 760 Waltonville Road 1-lummelatown PA 17036 66-3810 148 Model Aviation
Edition: Model Aviation - 1990/01
Page Numbers: 36, 37, 145, 148
George M Mye Radio Thchnque 70 Froebllch Farm Rd Hkksvlfle NY 11801 ABSTRACT More Alaska trip Lanier Laser GeeBee floats Porta-Sol kit DFS Sailplane SAID February 1989 column would take Lanier Seabird trip Alaska turned out too bulky made last-minute decision take Lanier Laser instead Laser stored neatly out way ceiling van bungees Bun gees long cloth-covered rubberbands about 5/~ in diameter fitted hooks ends Im hack New York again after wonderful summer Alaska smarter things did preparing trip remove screws holding terior moldings vans windows time slip swivel hanger meant hang ing pictures before putting screw back gave little wire loops over van taching bungees drive van know set pencil down somewhere will go corner van within next few miles bungees use better things will stay place Stock #4SPH B&R Specialty Hardware PO Box 0095 Baldwin NY 11510 Find bubble cards hanging picture hardware section clipped off lug containing outside hole neater appear ance Lanier Laser constructed plasticsheeted foam-cored wing horizontal tail balsa fin control surfaces styrene shell over plywood fuselage weighs 6 lb 6 oz radio engine installed minus fuel landing gear Length 505 wingspan 59 wing area 600 sq Splash some Hobbypoxy plywood have almost-waterproof plane engine trusty old 1980 05 60 FSR pump mounted Edson adjustable metal mount turn firewall mounted way four Davis ISO-Mount vibration isola tors can see photo installation page 79 Model Aviation June 89 engine fully cowled has K&B air cleaner its Perry carburetor keeps wa ter out engine Besides plenty dust Alaska turns 12 x 6 propeller hold airplane engine running see engine moving around inside cowl ing dont feel much vibration air frame made sound-level check ground nine feet read 88 dBA stan dard OS muffler engine dB meter peaked 73 dBA during full-speed flyby Palmer AK plane about 10 ft Out 10 ft up theory will radiate less noise less damage airplane its contentswhen isolate engine airframe practice plane sounds quieter other 60-powered ships plenty fast Ketchikan AK first stop Alaska has no flat land RC flying done water brought along 33-in Gee Bee floats 67% fuselage length spaced 13 apart 40% float length top floats 1 below tip prop floats tached airplane two aluminum straps Left Grandpa starls em out early Kevin Myers Georges youngest grandson prepares board Grandpas Lanier Laser GeeBee 33-in floats Right Triton Models -scale DFS Sailplane Triton located Kotzebue Alaska thats Address column Left Do transport models van George installed bunch swivel hangers van raves about convenience fastening bungee cords em Right Lanier Lasers wheel pant mounted help Goldberg Models nose wheel steering tiller arm screwed interior pant shell Minor surgery plastic tiller required Neat Easy Convenient info column 36 Model Aviation supplied Lanier kit landing gear bolted fuselage tal four 1A x 20 Du-Bro nylon bolts water rudder right-hand float driven pushrod control horn air rudder Eight pieces 1A6 x 34 x 4-in dural angles sand wiched four mounting tabs Gee Bee floats keep rocking last two ad ditions made Bob Andrew Ketchi kan Rainbirds RC Club complete assembly adds 1 lb 9 oz plane flight drag floats makes air plane neutral ie flies inverted Down elevator used Gee Bees because because installation simple make because work Larger floats per advice Floats & Fittings Ed Westwood October 1989 MA would easier beginners handle water cost additional weight drag Im ginner can take choice Laser has flown off both rough smooth water wind combination described above works use full Up elevator feed power gradually getting up step takeoff otherwise prop eats lot water make water landings step because am quite sure model will nose over dont flying rough water take off land parallel wave crests checked out pontoon installation swimming pool home before making perma nent Laser floats fresh water about 1 pontoons above surface along length fuel tank full floats little tail-low tank empty either case push wing tip down water plane pops up onto floats again soon release wing push prop tip un der water itpops out again too long fu selage less J0 nose-down water also brought along pair Dave Browns sponge-tired wheels use wheel pants provided kit flying off pavement larger Du-Bro lightweight tires flying off turf might interested mounted wheel pants Installation begins Du-Bro axle HalIco-type bent aluminum strap Next drilled axle-size hole through wheel pants per kit instructions Now cute part installed Goldberg Continued page 145 CARBON FIBER LAMINATES Aerospace Composite Products offers variety rigid carbon fiber/epoxy sheets add stiffness almost material- fiberglass foam bal sawood laminates can used reinforce foam wings leading trailing edges wing spars Carbon Fiber bonds easily slow setting cyanoacrylates 5-minute epoxies laminate can stripped narrower widths CL-i 007 thick 1x48-$50O 1x72-$7OO CL-2 014 thick 1x48-$8OO 1x72-$11O0 Send SASE information additional sizes products Add $300 shipping handling Calif residents add 6% tax Overseas orders odd 15%-Order COD send check money order I- IThe source lightweight materials PO Box 16621 Dept M Irvine CA 92714 714 250-1107 h. January 1990 37 New Model P-1K Porta-Sol portable butanefueled heat wand can used soldering hof-krsife cutting making on-field repairs MonoKote etc George loves gives comments ordering Info column executing first maneuvers Aileron throw may need adjusted recommend somewhat throw lower power less high-priced systems plans show average throws throw easily changed adjusting position screw-on nylon pieces threaded horns flown fairly aggressively Gold Fire-equipped version turned flight times four 4 minutes Installed fer rite 15 plane flew 4/2-to-five-minute runs Whichever power system youre us ing flights can stretched over seven minutes gentler handling air proper use speed control Good Luck Skyvolt hope have much fun quiet flying hours Ive Please dont hesitate send comments ques tions Id also welcome photos fin ished beauty closing want acknowl edge local modeler Bob Clauss suggest ing models name responding advertisers mention read about Model Aviation Continued page 37 tiller bar normally used nose-wheel steering outboard side wheel inside pant attached pant way #2 sheet metal screws type normally used mounting servos Cutting off excess screw length completed installation Since wanted tiller arm flat against wheel pant drill new hole through tiller bar plastic after pushing out metal wheel collar bore plastic til ler put setscrew bottom can easily get Put wheel collar back place its setscrew hole matching new hole youve just drilled tiller Finally file flat axle wheel pant wont fall off immediately after attaching screw becomes little loose New Porta-Sol kit pocket-size Porta-Sol butane-fueled flameless soldering iron Radio Technique February 88 issue MA page 38 proved very handy tool trip used sorts things like installing connec tort shrinking shrink-tubing insulators putting holes plastic etc point remem ber using solder wire back coil Quadra someone field somewhere fact burns cigarette-lighter Butane can lit sparker built its cap virtu ally windproof makes usable almost anywhere Porta-Sol now offers better versatile kit P-lK containing black Porta-Sol four kinds tools tip cleaner hot stand handy box measuring 15 x 3 x 9 like neat kits put useful tools easily stored pack ages Ive added P-tK van new kit features tools plastic retaining screws permit remove/install tools hot interchangeable older orange model al lowed cool first new internally heated tools heat range equivalent electric sol dering irons 10 60 watts very useful de signs Tools include I Standard %2 tip same size older model Other tip sizes 040 %2 Y6 available $899 2 Hot knife Integral design much thicker X-Acto blade sharp fine cut ting plastic sheet sailcloth etc 3 Pencil torch tiny flame fine soldering etc 4 Hot air gun 3R2-diameter source hot air use shrink tubing taking small wrinkles out MonoKote etc really like tool cause tip small Y16 dia x 1 long has no exposed flame can get down inside things dont touch tip sliding shutter anything after have lit fire As before kit made available ser January 1990 145 Radio Technique/Myers THE TAILGEAR SPJtT PASTERN SPORTSCALE Pat Pend flROVE GROUND RANDLfl4G ABSORB SNK TO AIRFRAME AND SERVO DIFFERERTIAL TEROW FOUSIRLE MAT NE INSTALLED IN Mt EflSTIEO BRACKET BRACKET INTERNAL FuSELAGE MOUNT EAST INSTALLATION EASILY ADJUSTABLE NONBINDING COMPLETE INSTALLATION FACEAGE* Mt 1d Q SMALL iO 1AEDIUM6O LABOE 120 TO CNiDER send ns ~ss andEFLigit Industries size desired sith 610 Th16 Woodnore Lane P&a INCLUDER Chattanooga TN 3Thfl FW4 B4OI FREE CATALOG Best 40 Ever 4 Channel nch Span -Symmetrical Wing 25 - 40 Engine 3 3-1/2 lbs Superior Performance Available Favorite Hobby ShopTi4ewoLeL Guaranteed Satisfaction~- 3925-C SE 45th Court IdE/tsiIuaIhIflAOcala FL 32671 S IA41eL FVI44~d lEE 6943531 FULL BODY PILOT KIT DARNED GOOD AIRMEN Lightest pilots available Lifelike vinyl latex rubber cap goggles full templates easy instruc Build Sportsman Barnstormer Full Body Bust V Contains pilot head hands boots helmet lions Easy assemble finish Some simple sewing required Fully BUST PILOT KITpositionable tool Pta Contains pilot head helmet apart cap goggles#206-A sca895 L#205hi jacket Easy assemble finishA scee995 Per-#204- sea1095 #108-1A scaleNEW#203-A scae695 #1061/ scale #l05-/n scale795 scale895* some scale 1495 mpie aew ng equ Gd JET PILOT KIT Pilot has molded jet helmet Contains face mask oxygen hose Extreme ly Realistic Weighs less V2 oz Pea #308-A scale 595 #307-V scale 695 ORDERING INSTRUCTIONS See dealer first order direct Add $100 shipping NYS residents add 7% lax Send check money order CODS OK Send $100 catalog See Dealer add Dollar direct otder handling vice modelers friend Les Shine doing business Bentley Electronics 106 Wedgewood Drive Hauppauge NY 11788 telephone 1800/634-6306 also available through SR Bat teries P-IK fuel Stock # 50A18107 can shipped air $5499 Fuel can purchased cigar counters shipped surface UPS Ask Colibri butane 34 fi oz Stock # 50A18106 $399 Scale Sailplane kit visiting Kotzebue AK tiny village above Arctic Cir cle right Bering Sea 65 miles Si beria made acquaintance Greg Harding doing business Triton Models Box 1157 Kot zebue AK 99752 telephone 1-707/442-2617 Kotzebue just about out-of-the-way place imaginable find model manu facturer time Greg offering nice fiberglass-bodied 4-scale model 1937 DFS Reicher gull-winged sailplane former ly flown Hanna Reicher Hanna Germanys foremost aviatrix es put name history books flew Focke-WuIf twin-rotor helicopter side Olympic Stadium Berlin about 1939 Scale enthusiasts might want give Greg call Time Kotzebue two hours earlier Pa cific Standard Time keep mind call ie 800 am New York 300 am Kotzebue Propeller Noise Continued page 41 ities Although 12 x 6 propeller has higher peak efficiency occurs lower flight speeds Such propeller would ef ficient near takeoff conditions perform poorly high flight speeds Equally impor tant assuming torque loading ma jor cause propeller noise props efficient high speeds will provide re duced noise levels no compromise performance Torque noise Several other findings impli cate torque loading dominant compo nent propeller noise Figure 4 shows plot SPL blade-passing fre quency BPF measured lab about 90 tant rotational speed Also shown curve generated using ac cepted empirical theory torque noise has shown correlate very closely experimental data Since havior SPL shaft power follows expected behavior torque noise can reasonably conjecture measured noise source fact torque noise broader view data obtained examining total acoustic power sound power radiated measurement de rived integration acoustic pres sure over space sound power can compared relation between sound power shaft power classical theory propeller noise developed years ago researcher named Gutin Figure 5 shows comparison 10500 rpm simulated flight speed 100 ft/sec Note agreement tween acoustic power data Gutin theory quite close correlation tween results shown Fig ure 4 view complications associ ated combining sufficient measure ments integrating data obtain acoustic power such consistency between two sets data unexpected Both re sults point torque-related noise leading element propeller sound reader will recall propeller efficiency low work engine must used overcome torque propeller rather produce thrust plot propulsive efficiency against sound power several different props assuming acoustic power derived primarily torque loads lat ter would rise propeller efficiency de clined Due variability thrustrelated noise however such plot would meaningful thrust held constant As shown plot Figure 6 noise due thrust held constant acoustic output varies propeller diameter ac cording propeller efficiency further corroborates dominant noise mechanism sound due torque loading propeller blades thrust-related noise dominant sound power vari ation Figure 6 would nearly con stant point can see constant thrust does lead constant noise Continued page 150 4 Championship Design Outstanding4 Strong & Stable New Combat/Sport4 FastEasyAssembly Plane4 High Performance Includes Complete Hardware ine Included Belicrank outs s 0 Hinges s & Nuts $100 catalog Precision Foam Wing Corescontrol-line combat specialties Dealer & Distributor inquiries Welcome 760 Waltonville Road 1-lummelatown PA 17036 66-3810 148 Model Aviation
Edition: Model Aviation - 1990/01
Page Numbers: 36, 37, 145, 148
George M Mye Radio Thchnque 70 Froebllch Farm Rd Hkksvlfle NY 11801 ABSTRACT More Alaska trip Lanier Laser GeeBee floats Porta-Sol kit DFS Sailplane SAID February 1989 column would take Lanier Seabird trip Alaska turned out too bulky made last-minute decision take Lanier Laser instead Laser stored neatly out way ceiling van bungees Bun gees long cloth-covered rubberbands about 5/~ in diameter fitted hooks ends Im hack New York again after wonderful summer Alaska smarter things did preparing trip remove screws holding terior moldings vans windows time slip swivel hanger meant hang ing pictures before putting screw back gave little wire loops over van taching bungees drive van know set pencil down somewhere will go corner van within next few miles bungees use better things will stay place Stock #4SPH B&R Specialty Hardware PO Box 0095 Baldwin NY 11510 Find bubble cards hanging picture hardware section clipped off lug containing outside hole neater appear ance Lanier Laser constructed plasticsheeted foam-cored wing horizontal tail balsa fin control surfaces styrene shell over plywood fuselage weighs 6 lb 6 oz radio engine installed minus fuel landing gear Length 505 wingspan 59 wing area 600 sq Splash some Hobbypoxy plywood have almost-waterproof plane engine trusty old 1980 05 60 FSR pump mounted Edson adjustable metal mount turn firewall mounted way four Davis ISO-Mount vibration isola tors can see photo installation page 79 Model Aviation June 89 engine fully cowled has K&B air cleaner its Perry carburetor keeps wa ter out engine Besides plenty dust Alaska turns 12 x 6 propeller hold airplane engine running see engine moving around inside cowl ing dont feel much vibration air frame made sound-level check ground nine feet read 88 dBA stan dard OS muffler engine dB meter peaked 73 dBA during full-speed flyby Palmer AK plane about 10 ft Out 10 ft up theory will radiate less noise less damage airplane its contentswhen isolate engine airframe practice plane sounds quieter other 60-powered ships plenty fast Ketchikan AK first stop Alaska has no flat land RC flying done water brought along 33-in Gee Bee floats 67% fuselage length spaced 13 apart 40% float length top floats 1 below tip prop floats tached airplane two aluminum straps Left Grandpa starls em out early Kevin Myers Georges youngest grandson prepares board Grandpas Lanier Laser GeeBee 33-in floats Right Triton Models -scale DFS Sailplane Triton located Kotzebue Alaska thats Address column Left Do transport models van George installed bunch swivel hangers van raves about convenience fastening bungee cords em Right Lanier Lasers wheel pant mounted help Goldberg Models nose wheel steering tiller arm screwed interior pant shell Minor surgery plastic tiller required Neat Easy Convenient info column 36 Model Aviation supplied Lanier kit landing gear bolted fuselage tal four 1A x 20 Du-Bro nylon bolts water rudder right-hand float driven pushrod control horn air rudder Eight pieces 1A6 x 34 x 4-in dural angles sand wiched four mounting tabs Gee Bee floats keep rocking last two ad ditions made Bob Andrew Ketchi kan Rainbirds RC Club complete assembly adds 1 lb 9 oz plane flight drag floats makes air plane neutral ie flies inverted Down elevator used Gee Bees because because installation simple make because work Larger floats per advice Floats & Fittings Ed Westwood October 1989 MA would easier beginners handle water cost additional weight drag Im ginner can take choice Laser has flown off both rough smooth water wind combination described above works use full Up elevator feed power gradually getting up step takeoff otherwise prop eats lot water make water landings step because am quite sure model will nose over dont flying rough water take off land parallel wave crests checked out pontoon installation swimming pool home before making perma nent Laser floats fresh water about 1 pontoons above surface along length fuel tank full floats little tail-low tank empty either case push wing tip down water plane pops up onto floats again soon release wing push prop tip un der water itpops out again too long fu selage less J0 nose-down water also brought along pair Dave Browns sponge-tired wheels use wheel pants provided kit flying off pavement larger Du-Bro lightweight tires flying off turf might interested mounted wheel pants Installation begins Du-Bro axle HalIco-type bent aluminum strap Next drilled axle-size hole through wheel pants per kit instructions Now cute part installed Goldberg Continued page 145 CARBON FIBER LAMINATES Aerospace Composite Products offers variety rigid carbon fiber/epoxy sheets add stiffness almost material- fiberglass foam bal sawood laminates can used reinforce foam wings leading trailing edges wing spars Carbon Fiber bonds easily slow setting cyanoacrylates 5-minute epoxies laminate can stripped narrower widths CL-i 007 thick 1x48-$50O 1x72-$7OO CL-2 014 thick 1x48-$8OO 1x72-$11O0 Send SASE information additional sizes products Add $300 shipping handling Calif residents add 6% tax Overseas orders odd 15%-Order COD send check money order I- IThe source lightweight materials PO Box 16621 Dept M Irvine CA 92714 714 250-1107 h. January 1990 37 New Model P-1K Porta-Sol portable butanefueled heat wand can used soldering hof-krsife cutting making on-field repairs MonoKote etc George loves gives comments ordering Info column executing first maneuvers Aileron throw may need adjusted recommend somewhat throw lower power less high-priced systems plans show average throws throw easily changed adjusting position screw-on nylon pieces threaded horns flown fairly aggressively Gold Fire-equipped version turned flight times four 4 minutes Installed fer rite 15 plane flew 4/2-to-five-minute runs Whichever power system youre us ing flights can stretched over seven minutes gentler handling air proper use speed control Good Luck Skyvolt hope have much fun quiet flying hours Ive Please dont hesitate send comments ques tions Id also welcome photos fin ished beauty closing want acknowl edge local modeler Bob Clauss suggest ing models name responding advertisers mention read about Model Aviation Continued page 37 tiller bar normally used nose-wheel steering outboard side wheel inside pant attached pant way #2 sheet metal screws type normally used mounting servos Cutting off excess screw length completed installation Since wanted tiller arm flat against wheel pant drill new hole through tiller bar plastic after pushing out metal wheel collar bore plastic til ler put setscrew bottom can easily get Put wheel collar back place its setscrew hole matching new hole youve just drilled tiller Finally file flat axle wheel pant wont fall off immediately after attaching screw becomes little loose New Porta-Sol kit pocket-size Porta-Sol butane-fueled flameless soldering iron Radio Technique February 88 issue MA page 38 proved very handy tool trip used sorts things like installing connec tort shrinking shrink-tubing insulators putting holes plastic etc point remem ber using solder wire back coil Quadra someone field somewhere fact burns cigarette-lighter Butane can lit sparker built its cap virtu ally windproof makes usable almost anywhere Porta-Sol now offers better versatile kit P-lK containing black Porta-Sol four kinds tools tip cleaner hot stand handy box measuring 15 x 3 x 9 like neat kits put useful tools easily stored pack ages Ive added P-tK van new kit features tools plastic retaining screws permit remove/install tools hot interchangeable older orange model al lowed cool first new internally heated tools heat range equivalent electric sol dering irons 10 60 watts very useful de signs Tools include I Standard %2 tip same size older model Other tip sizes 040 %2 Y6 available $899 2 Hot knife Integral design much thicker X-Acto blade sharp fine cut ting plastic sheet sailcloth etc 3 Pencil torch tiny flame fine soldering etc 4 Hot air gun 3R2-diameter source hot air use shrink tubing taking small wrinkles out MonoKote etc really like tool cause tip small Y16 dia x 1 long has no exposed flame can get down inside things dont touch tip sliding shutter anything after have lit fire As before kit made available ser January 1990 145 Radio Technique/Myers THE TAILGEAR SPJtT PASTERN SPORTSCALE Pat Pend flROVE GROUND RANDLfl4G ABSORB SNK TO AIRFRAME AND SERVO DIFFERERTIAL TEROW FOUSIRLE MAT NE INSTALLED IN Mt EflSTIEO BRACKET BRACKET INTERNAL FuSELAGE MOUNT EAST INSTALLATION EASILY ADJUSTABLE NONBINDING COMPLETE INSTALLATION FACEAGE* Mt 1d Q SMALL iO 1AEDIUM6O LABOE 120 TO CNiDER send ns ~ss andEFLigit Industries size desired sith 610 Th16 Woodnore Lane P&a INCLUDER Chattanooga TN 3Thfl FW4 B4OI FREE CATALOG Best 40 Ever 4 Channel nch Span -Symmetrical Wing 25 - 40 Engine 3 3-1/2 lbs Superior Performance Available Favorite Hobby ShopTi4ewoLeL Guaranteed Satisfaction~- 3925-C SE 45th Court IdE/tsiIuaIhIflAOcala FL 32671 S IA41eL FVI44~d lEE 6943531 FULL BODY PILOT KIT DARNED GOOD AIRMEN Lightest pilots available Lifelike vinyl latex rubber cap goggles full templates easy instruc Build Sportsman Barnstormer Full Body Bust V Contains pilot head hands boots helmet lions Easy assemble finish Some simple sewing required Fully BUST PILOT KITpositionable tool Pta Contains pilot head helmet apart cap goggles#206-A sca895 L#205hi jacket Easy assemble finishA scee995 Per-#204- sea1095 #108-1A scaleNEW#203-A scae695 #1061/ scale #l05-/n scale795 scale895* some scale 1495 mpie aew ng equ Gd JET PILOT KIT Pilot has molded jet helmet Contains face mask oxygen hose Extreme ly Realistic Weighs less V2 oz Pea #308-A scale 595 #307-V scale 695 ORDERING INSTRUCTIONS See dealer first order direct Add $100 shipping NYS residents add 7% lax Send check money order CODS OK Send $100 catalog See Dealer add Dollar direct otder handling vice modelers friend Les Shine doing business Bentley Electronics 106 Wedgewood Drive Hauppauge NY 11788 telephone 1800/634-6306 also available through SR Bat teries P-IK fuel Stock # 50A18107 can shipped air $5499 Fuel can purchased cigar counters shipped surface UPS Ask Colibri butane 34 fi oz Stock # 50A18106 $399 Scale Sailplane kit visiting Kotzebue AK tiny village above Arctic Cir cle right Bering Sea 65 miles Si beria made acquaintance Greg Harding doing business Triton Models Box 1157 Kot zebue AK 99752 telephone 1-707/442-2617 Kotzebue just about out-of-the-way place imaginable find model manu facturer time Greg offering nice fiberglass-bodied 4-scale model 1937 DFS Reicher gull-winged sailplane former ly flown Hanna Reicher Hanna Germanys foremost aviatrix es put name history books flew Focke-WuIf twin-rotor helicopter side Olympic Stadium Berlin about 1939 Scale enthusiasts might want give Greg call Time Kotzebue two hours earlier Pa cific Standard Time keep mind call ie 800 am New York 300 am Kotzebue Propeller Noise Continued page 41 ities Although 12 x 6 propeller has higher peak efficiency occurs lower flight speeds Such propeller would ef ficient near takeoff conditions perform poorly high flight speeds Equally impor tant assuming torque loading ma jor cause propeller noise props efficient high speeds will provide re duced noise levels no compromise performance Torque noise Several other findings impli cate torque loading dominant compo nent propeller noise Figure 4 shows plot SPL blade-passing fre quency BPF measured lab about 90 tant rotational speed Also shown curve generated using ac cepted empirical theory torque noise has shown correlate very closely experimental data Since havior SPL shaft power follows expected behavior torque noise can reasonably conjecture measured noise source fact torque noise broader view data obtained examining total acoustic power sound power radiated measurement de rived integration acoustic pres sure over space sound power can compared relation between sound power shaft power classical theory propeller noise developed years ago researcher named Gutin Figure 5 shows comparison 10500 rpm simulated flight speed 100 ft/sec Note agreement tween acoustic power data Gutin theory quite close correlation tween results shown Fig ure 4 view complications associ ated combining sufficient measure ments integrating data obtain acoustic power such consistency between two sets data unexpected Both re sults point torque-related noise leading element propeller sound reader will recall propeller efficiency low work engine must used overcome torque propeller rather produce thrust plot propulsive efficiency against sound power several different props assuming acoustic power derived primarily torque loads lat ter would rise propeller efficiency de clined Due variability thrustrelated noise however such plot would meaningful thrust held constant As shown plot Figure 6 noise due thrust held constant acoustic output varies propeller diameter ac cording propeller efficiency further corroborates dominant noise mechanism sound due torque loading propeller blades thrust-related noise dominant sound power vari ation Figure 6 would nearly con stant point can see constant thrust does lead constant noise Continued page 150 4 Championship Design Outstanding4 Strong & Stable New Combat/Sport4 FastEasyAssembly Plane4 High Performance Includes Complete Hardware ine Included Belicrank outs s 0 Hinges s & Nuts $100 catalog Precision Foam Wing Corescontrol-line combat specialties Dealer & Distributor inquiries Welcome 760 Waltonville Road 1-lummelatown PA 17036 66-3810 148 Model Aviation