CONTROL LINE NAVY CARRIER THIS MONTHS OFFERINGS include discussion balance points Carrier models bit theory support computerized scoring program Melvin Schuette NATS Special Events As announced last column Navy Carrier Society will sponsor Sportsman Profile Carrier Saturday following regular CL Navy Carrier competition flying National Aeromodeling Championships same day Dallas-area Carrier modelers will sponsor 15 Carrier eventWhen written early April sponsor Skyray Carrier Navy Carrier Society newsletter will contain latest information Nats Carrier activities Thanks Bill Bischoff rest Dallas carrier gang offering host 15 Carrier Carrier Model Selection last column promised discuss balancing Carrier models ensure acceptable handling qualities both high- low-speed flight has little written about technical aspects subject modeling magazines what has written has subject least little controversy few readers try point out errors author Having sending end some discussions past Im now embarking potentially hazardous course including such technical information own column Lest purists jump too hastily typewriters let point out intent provide simplified condensed therefore academically rigorous 100% accurate information might useful readers size location horizontal tail important determining well model can controlled low-speed flight same true high-speed flight way larger tail area located greater distance balance point would effective smaller closer horizontal tail other significant factors tail volume ratio equation length Mean Aerodynamic Chord MAC wing As MAC increases tail volume ratio control effectiveness decreases other factors remain sameThe MAC primary dimensions used stability control determinations aircraftboth models full-scale used because represents entire wings aerodynamic characteristics single airfoil fixed dimensions location Positioning balance point model logically involves locating relation wing Because MAC represents entire wing need accurately determine MAC MAC T x JJR2T 3 RT / Y H Y LEADING EDGE 5 CENTER OF LiFT RMAC25% MAC EQUAL AREAS x H figure 1 MACW MAC2X2 — x xw 2 Ii ci MAC x-x 2 DETERMINE SETBACK Y FOR MACW GRAPI-JICALLY AS SI-ION Y w MACW MAC2 figure 2 N LTST S, O N j 25 MACWNEUTRAL POINT 25% / MAC figure 3 accurately consistently position balance point model whod prefer pass up theory get right meat issue can skip next few paragraphs interested what Im writing about want complain about butchering 108 Model Aviation ge Liebs profile Wildcat Omaha Orbiting Eagles Frozen Finger Flying Festival Bob Furr photo pure~ technical aspects read aircraft fly straight level forces acting must balance same goes torque twisting moments forces produce forces moments dont balance other aircraft going change its direction motion its attitude usually both control line flying concerned primarily about pitch because force lines provides stability roll yaw spite aerodynamic forces level flight total upward force lift wing tail primarily must balance total downward force weight plus additional contribution lines whenever flying height higher control handle weight effects act balance point model lift wing tail act through point 25% aft leading edge MAC conventional aircraft tail behind wing two possible force configurations either balance point front center lift wing 25% MAC balance point behind center wing lift CL models often balance front wing center lift configuration requires downward force tail keep model balanced pitch downward tail force requires corresponding increase wing lift keep forces balanced vertically Free flight models often use balance point aft wing center lift tail can contribute total lift thus increase glide performance Both configurations can stable obviously FF models couldnt balanced Another factor stability control discussion static stability want aircraft fly hands offto keep going direction want go until make control input aircraft has positive static stability will return its initial flight conditions disturbed turbulence other factors Positive stability good aircraft has negative static stability small change attitude * * Long Engine Life * * Use BRU LINE Air Cleaner Completely Fuel Proof Nylon Rubber Parts Cat No 102 Air Cleaner Coarse $299 Cat No 202 Air Cleaner Fine $299 Replacement Inserts Cat No 104 Pkl2 Inserts Coarse $239 Cat No 204 Pkl2 Inserts Fine $239 FITS MOST ENGINES 25and UP SEE YOUR LOCAL HOBBY DEALER IF UNAVAILABLE LOCALLY SEND TO Bru Line Industries Inc P0 Box 3786 Center Line Michigan 48015 Add $250 sh pp ngM ch gan residents add 4% sales tax p p mm U IKAVI7 i Small Tool Specialists TO ORDER Send $100 ibis Brand Names. Unusual Items OVER 2000 TOOLS & ACCESSORIES IODAY IExclusive Products-many say ngs up 60% designed make prolect easier enjoyable professional INAME name address ADDRESS coupon br MicroMark340-1617 Snyder Ave L Berkely Heights NJ 07922-1595CITYSTATE ZIP r can letter mu model Simple &vd66ckae B Pressure Sensitive Water Transfer major decals 11 sizes 11 great colors RTHEAST SCREEN GRAPHICS 21 FISHER AVE EAST LONGMEADOW MA 01025 TEL 413-5254110 FAX 413-525-77R August1994 109 REICHMUTH IGNITIONS [Electronic advance systems no moving parts] complete electronics fixed mechanical advance systems Direct replacement popular systems CUSTOM COMPONENTS Reichmuth Ignitions will supply capacitor discharge spark coils circuit boards fixed electronic advance systems harness both switch Hall sensors Call write information quotes Dan Reichmuth 517 Ave D San Manuel AZ 85631 602 385-2511 Mountain Time SIG MANUFACTURING CO now imports complete line world record holding ROSSI aircraft marine helicopter race car engines includes full line parts accessories plus full time ROSSI REPAIR CENTER US SIG-imported ROSSI engines come full 90 day SIG WARRANTY against work manship manufacturing defects SIG MANUFACTURING CO INC . Montezuma IA 50171 PH 515-623-5154FAX 515-623-3922Toll Free Orders 800-247-5008 G0TOR RIC Products Inc SOFT-N-SAFE ENGINE MOUNTS Soft Mount using special serrated Iso-Damp Grommets Engine always safely retained Very effective vibration reduction dramatic decrease engine shake Light machined aluminum beam mounts 60 2-strokes 120 4-strokes available Also available aluminum radial mount 60 2-strokes Soft-N-Safe 120 beam mount complete . $3495 Soft-N-Safe 60 beam mount complete 95 SoftN-Safe 60 radial mount complete 95 Soft-N-Safe Replacement Iso-Damp Grommets Pkg 4 60$295 Pkg 4 tori 20$595 RADIAL ISO-MOUNTS Conventional backplate type mount using four Lord-Type 60-Duro IsoMounts Optimized lowest vibration transmission airframe reduced engine shake Radial Iso-mount complete $1495 Iso-Mounts Package 4 $995 5/8 diameter x 1/2 long 8-32 female end 8-32 x 1/2 male other end 60-Duro rubber TIONS -5 ----est Fuselage Provides solid support accurate building Rugged 7-ply aircraft plywood construction Two sizes available Regular fuse up 6-1/4 wide Jumbo fuse up 9-1/4 wide Use building board base mount Uni-Strut Guide Rails versatile set-up Contains hardware & instructions including Uni-Strut information Box 4 Standard Jig Stations $2195 Box 4 Jumbo Jig Stations 2395 2 Five Ft Guide Rails & Mounting Nuts . $2295 GLASS CLOTH 7 oz/Sq Yard est Filling est Weave Lightest Finished Weight Includes Detailed Instructions Big 3 Square Yard Pkg $895 R/C Products Inc 3713 Pompano Drive Pensacola FL 32514 904/494-0203 904/494-0207 VISA/MasterCard Welcomed $4 00 per item S&H esidents add 8% Tax control forces will cause aircraft divergeto continue increase its deviation original conditions Such situation obviously bad can extreme result model trying turn around fly backwards nose aircraft pitches up unintentionally because turbulence whatever lift wing tail changesboth will increase tail pushing down forward balance point tails downward force will decrease change upward force Both wing tail will experience approximately same change lift coefficient change actual lift surface proportional change lift coefficient same both wing tail times area surfaceIf balance point forward wing center lift can easily see increase lift aft balance point caused both wing tail will tend lift tail return model level flight conventional airplane positive static stability balance point can behind wing center lift case increase wing lift tends increase pitch attitude farther pitching moment product increase lift times distance wing center lift balance point increase tails lift able overcome effect because tail farther away balance point its moment lift times distance balance point greater moment caused wing As balance point moves aft will reach point pitch-up moment caused wing pitchdown moment caused tail will balance other point called neutral point neutral ground between positive negative stability key static stability handling qualities term referred static margin defined distance usually expressed percentage MAC between balance point neutral point greater static margin stable model will the elevators will have work overcome stability make model maneuver good handling qualities need positive static stabilitythe model must balance forward neutral point As static margin increases elevator control becomes less effective less sensitive achieve good stable high-speed handling qualities well good effective elevator control low-speed characteristics compromise necessary Such compromise experience places balance point about 30% MAC forward neutral point static margin equals 30% MAC static margin rather large compared full-scale aircraft reason propeller mounted front aircraft usual fashion tends make aircraft unstable powerful engines longer noses increase effect Compared full-scale aircraft engines model engines much powerful models require larger static margins compensate Enough theory make work first step determine MAC wing horizontal tail rectangular wing MAC wing chord rectangular wing swept back rather straight place MAC wing half distance centerline tip Tapered wings present little challenge much rough calculations approximation last column will suffice purists MAC lies centroid wing planform half wingcenterline tip want avoid math can draw wing half cardboard cut out determine balance point centroid cardboard Assume MAC chord passes through balance point Remember purposes wing outline extends fuselage way centerline aircraft mathematically determine MAC 110 Model Aviation R YOU DID ALL THE WORK WHY LET YOUR AIRPLANE DO ALL THE FLYING BUILD & FLY THE miniMAX YOURSELF y .omputer Designed3 Axis control Reserve Grand Champion Ultralight Part 103 Ultralight- Easy Construction 1989 Sun-N-Fun Fly-In Wood ConstructionVideoAvailable information send $500 TEAM INC 10790-MA Ivy Bluff Rd Bradyville TN 37026 765-5397 tapered wing refer Figure 1 Since wings have some type wingtip other convenient square tip must approximate tip chord equations Draw theoretical square wingtip point tip area outboard theoretical tip would fill vacant areas inboard theoretical tip Extend leading edge trailing edge theoretical tip position use outline equivalent planform Note tip chord zero delta wing Terms used Figure 1 R chord T chord H span X wise location MAC S Setback tip chord sweep tip Y ack MAC models wing consists two sections MO-i can calculate MAC section combine two get MAC entire wing method shown Figure 2 subscripts used Figure 2 refer two segments 1 inboard 2 outboard make up wing W subscript refers entire wing Terms used Figure 2 X wise location MACs S wing segments Once have determined MAC wing tail neutral point determined using method Figure 3 Most terms self-explanatory tail moment arm LT used calculations distance between 25% MAC points wing tail result calculation decimal convert percent represents distance leading edge MAC neutral point distance percent MAC therefore will valid size model same configuration Ive listed approximate neutral points same aircraft appeared last column Notice neutral points almost behind midpoint MAC good flying qualities balance point CL Navy Carrier model should about 30% MAC forward neutral point static margin equal 30% MAC fuel tank forward balance point adjust balance point account fuel expect have tank end flight 30% figure will produce model will handle reasonably well Fine tuning balance point match individual preferences will require test flying should find 30% figure pretty close static margin Carlos Aloise s Profile Carrier model 33% MAC Bill Bischoffs Sniper last column has static margin 28% MAC use about 28% MO-ls well Tom Schaefers Kingfisher used 32% static margin critical dimensions relate directly MAC measured aft MAC leading edge location MAC relation rest aircraft critical accurately determining neutral point balance point etc leading edge MAC unlikely correspond leading edge root chord Balance point becomes less critical models large tail volume ratios Therefore large tail volume ratio appropriate models have large fuel tanks mounted forward balance point Thats month hope see Lubbock Keep hook dry1 IALIST IN CUSTOM COX TEE DEE & REED ENGINES 020S 049S 051S 074S & 09S ALL CUSTOM & STOCK PARTS AVAILABLE INDIVIDUALLY COMPETITION ACCESSORIES RACING WHEELS KLOTZ OIL CARBON FIBER SOLID LINES ALL KINDS OF TUBING THREE BRANDS OF GLOW PLUGS HARD-TO-FIND HARDWARE OLD TIMER SUPPLIES COILS CONDENSERS NGK & STIlT SPARK PLUGS SILK 8 COLORS QUALITY DOPE BRUSHES 5 & 7 LOOP 114 RUBBERBANDS TRANSISTOR IGNITION SYSTEMS RESISTOR HIGH TENSION LEADS 1/2A TEXACO PLAYBOY SR KIT 112A TEXACO ENGINES & PARTS RUBBER POWER KITS PROPS TISSUE AND OTHER SUPPLIES CYANOACRYLATES & EPOXIES ORDER BY MAIL OR PHONE 619 728-4365 SORRY NO COD VISA & MASTERCARD WELCOME MINIMUM MERCHANDISE ORDER $1000 SHIPPING HANDLING AND INSURANCE FEE $395 STOCK ORDERS SHIPPED WITHIN 24 HRS August1994 111 OUR REV-UP INVENTORY AVERAGES OVER 9000 PROPSIII IMMEDIATE SHIPMENT VISA/MC GOLAIR RACINU LIVES NOW YOU CAN OWN UULLCTION 15- H IAMUUb MACING PLANES OF THE 30S LIKE THE GEE BEE Z GEEFor mntt P8CI e BEE R1 HALL BULLDOG WEDELL WILLIAMS AND CAUDF1ON RACER SCHOENFELOT FIRECRACKER ALL Smilhy Dept MA HIGHLY DETAILED 1I32 SCALE KITS SEND SASE FOR ILLUSTRATED ORDER FORM $300 FOR CATALOG 1-800-345-6342Lalhe Mill Drill WILLIAMS BROS INC 181 PAWNEE ST SAN MARCOS CA 92069 3023 E 2nd SIreel Ask operalor MAThe Dalles OR 97058
Edition: Model Aviation - 1994/08
Page Numbers: 108, 109, 110, 111
CONTROL LINE NAVY CARRIER THIS MONTHS OFFERINGS include discussion balance points Carrier models bit theory support computerized scoring program Melvin Schuette NATS Special Events As announced last column Navy Carrier Society will sponsor Sportsman Profile Carrier Saturday following regular CL Navy Carrier competition flying National Aeromodeling Championships same day Dallas-area Carrier modelers will sponsor 15 Carrier eventWhen written early April sponsor Skyray Carrier Navy Carrier Society newsletter will contain latest information Nats Carrier activities Thanks Bill Bischoff rest Dallas carrier gang offering host 15 Carrier Carrier Model Selection last column promised discuss balancing Carrier models ensure acceptable handling qualities both high- low-speed flight has little written about technical aspects subject modeling magazines what has written has subject least little controversy few readers try point out errors author Having sending end some discussions past Im now embarking potentially hazardous course including such technical information own column Lest purists jump too hastily typewriters let point out intent provide simplified condensed therefore academically rigorous 100% accurate information might useful readers size location horizontal tail important determining well model can controlled low-speed flight same true high-speed flight way larger tail area located greater distance balance point would effective smaller closer horizontal tail other significant factors tail volume ratio equation length Mean Aerodynamic Chord MAC wing As MAC increases tail volume ratio control effectiveness decreases other factors remain sameThe MAC primary dimensions used stability control determinations aircraftboth models full-scale used because represents entire wings aerodynamic characteristics single airfoil fixed dimensions location Positioning balance point model logically involves locating relation wing Because MAC represents entire wing need accurately determine MAC MAC T x JJR2T 3 RT / Y H Y LEADING EDGE 5 CENTER OF LiFT RMAC25% MAC EQUAL AREAS x H figure 1 MACW MAC2X2 — x xw 2 Ii ci MAC x-x 2 DETERMINE SETBACK Y FOR MACW GRAPI-JICALLY AS SI-ION Y w MACW MAC2 figure 2 N LTST S, O N j 25 MACWNEUTRAL POINT 25% / MAC figure 3 accurately consistently position balance point model whod prefer pass up theory get right meat issue can skip next few paragraphs interested what Im writing about want complain about butchering 108 Model Aviation ge Liebs profile Wildcat Omaha Orbiting Eagles Frozen Finger Flying Festival Bob Furr photo pure~ technical aspects read aircraft fly straight level forces acting must balance same goes torque twisting moments forces produce forces moments dont balance other aircraft going change its direction motion its attitude usually both control line flying concerned primarily about pitch because force lines provides stability roll yaw spite aerodynamic forces level flight total upward force lift wing tail primarily must balance total downward force weight plus additional contribution lines whenever flying height higher control handle weight effects act balance point model lift wing tail act through point 25% aft leading edge MAC conventional aircraft tail behind wing two possible force configurations either balance point front center lift wing 25% MAC balance point behind center wing lift CL models often balance front wing center lift configuration requires downward force tail keep model balanced pitch downward tail force requires corresponding increase wing lift keep forces balanced vertically Free flight models often use balance point aft wing center lift tail can contribute total lift thus increase glide performance Both configurations can stable obviously FF models couldnt balanced Another factor stability control discussion static stability want aircraft fly hands offto keep going direction want go until make control input aircraft has positive static stability will return its initial flight conditions disturbed turbulence other factors Positive stability good aircraft has negative static stability small change attitude * * Long Engine Life * * Use BRU LINE Air Cleaner Completely Fuel Proof Nylon Rubber Parts Cat No 102 Air Cleaner Coarse $299 Cat No 202 Air Cleaner Fine $299 Replacement Inserts Cat No 104 Pkl2 Inserts Coarse $239 Cat No 204 Pkl2 Inserts Fine $239 FITS MOST ENGINES 25and UP SEE YOUR LOCAL HOBBY DEALER IF UNAVAILABLE LOCALLY SEND TO Bru Line Industries Inc P0 Box 3786 Center Line Michigan 48015 Add $250 sh pp ngM ch gan residents add 4% sales tax p p mm U IKAVI7 i Small Tool Specialists TO ORDER Send $100 ibis Brand Names. Unusual Items OVER 2000 TOOLS & ACCESSORIES IODAY IExclusive Products-many say ngs up 60% designed make prolect easier enjoyable professional INAME name address ADDRESS coupon br MicroMark340-1617 Snyder Ave L Berkely Heights NJ 07922-1595CITYSTATE ZIP r can letter mu model Simple &vd66ckae B Pressure Sensitive Water Transfer major decals 11 sizes 11 great colors RTHEAST SCREEN GRAPHICS 21 FISHER AVE EAST LONGMEADOW MA 01025 TEL 413-5254110 FAX 413-525-77R August1994 109 REICHMUTH IGNITIONS [Electronic advance systems no moving parts] complete electronics fixed mechanical advance systems Direct replacement popular systems CUSTOM COMPONENTS Reichmuth Ignitions will supply capacitor discharge spark coils circuit boards fixed electronic advance systems harness both switch Hall sensors Call write information quotes Dan Reichmuth 517 Ave D San Manuel AZ 85631 602 385-2511 Mountain Time SIG MANUFACTURING CO now imports complete line world record holding ROSSI aircraft marine helicopter race car engines includes full line parts accessories plus full time ROSSI REPAIR CENTER US SIG-imported ROSSI engines come full 90 day SIG WARRANTY against work manship manufacturing defects SIG MANUFACTURING CO INC . Montezuma IA 50171 PH 515-623-5154FAX 515-623-3922Toll Free Orders 800-247-5008 G0TOR RIC Products Inc SOFT-N-SAFE ENGINE MOUNTS Soft Mount using special serrated Iso-Damp Grommets Engine always safely retained Very effective vibration reduction dramatic decrease engine shake Light machined aluminum beam mounts 60 2-strokes 120 4-strokes available Also available aluminum radial mount 60 2-strokes Soft-N-Safe 120 beam mount complete . $3495 Soft-N-Safe 60 beam mount complete 95 SoftN-Safe 60 radial mount complete 95 Soft-N-Safe Replacement Iso-Damp Grommets Pkg 4 60$295 Pkg 4 tori 20$595 RADIAL ISO-MOUNTS Conventional backplate type mount using four Lord-Type 60-Duro IsoMounts Optimized lowest vibration transmission airframe reduced engine shake Radial Iso-mount complete $1495 Iso-Mounts Package 4 $995 5/8 diameter x 1/2 long 8-32 female end 8-32 x 1/2 male other end 60-Duro rubber TIONS -5 ----est Fuselage Provides solid support accurate building Rugged 7-ply aircraft plywood construction Two sizes available Regular fuse up 6-1/4 wide Jumbo fuse up 9-1/4 wide Use building board base mount Uni-Strut Guide Rails versatile set-up Contains hardware & instructions including Uni-Strut information Box 4 Standard Jig Stations $2195 Box 4 Jumbo Jig Stations 2395 2 Five Ft Guide Rails & Mounting Nuts . $2295 GLASS CLOTH 7 oz/Sq Yard est Filling est Weave Lightest Finished Weight Includes Detailed Instructions Big 3 Square Yard Pkg $895 R/C Products Inc 3713 Pompano Drive Pensacola FL 32514 904/494-0203 904/494-0207 VISA/MasterCard Welcomed $4 00 per item S&H esidents add 8% Tax control forces will cause aircraft divergeto continue increase its deviation original conditions Such situation obviously bad can extreme result model trying turn around fly backwards nose aircraft pitches up unintentionally because turbulence whatever lift wing tail changesboth will increase tail pushing down forward balance point tails downward force will decrease change upward force Both wing tail will experience approximately same change lift coefficient change actual lift surface proportional change lift coefficient same both wing tail times area surfaceIf balance point forward wing center lift can easily see increase lift aft balance point caused both wing tail will tend lift tail return model level flight conventional airplane positive static stability balance point can behind wing center lift case increase wing lift tends increase pitch attitude farther pitching moment product increase lift times distance wing center lift balance point increase tails lift able overcome effect because tail farther away balance point its moment lift times distance balance point greater moment caused wing As balance point moves aft will reach point pitch-up moment caused wing pitchdown moment caused tail will balance other point called neutral point neutral ground between positive negative stability key static stability handling qualities term referred static margin defined distance usually expressed percentage MAC between balance point neutral point greater static margin stable model will the elevators will have work overcome stability make model maneuver good handling qualities need positive static stabilitythe model must balance forward neutral point As static margin increases elevator control becomes less effective less sensitive achieve good stable high-speed handling qualities well good effective elevator control low-speed characteristics compromise necessary Such compromise experience places balance point about 30% MAC forward neutral point static margin equals 30% MAC static margin rather large compared full-scale aircraft reason propeller mounted front aircraft usual fashion tends make aircraft unstable powerful engines longer noses increase effect Compared full-scale aircraft engines model engines much powerful models require larger static margins compensate Enough theory make work first step determine MAC wing horizontal tail rectangular wing MAC wing chord rectangular wing swept back rather straight place MAC wing half distance centerline tip Tapered wings present little challenge much rough calculations approximation last column will suffice purists MAC lies centroid wing planform half wingcenterline tip want avoid math can draw wing half cardboard cut out determine balance point centroid cardboard Assume MAC chord passes through balance point Remember purposes wing outline extends fuselage way centerline aircraft mathematically determine MAC 110 Model Aviation R YOU DID ALL THE WORK WHY LET YOUR AIRPLANE DO ALL THE FLYING BUILD & FLY THE miniMAX YOURSELF y .omputer Designed3 Axis control Reserve Grand Champion Ultralight Part 103 Ultralight- Easy Construction 1989 Sun-N-Fun Fly-In Wood ConstructionVideoAvailable information send $500 TEAM INC 10790-MA Ivy Bluff Rd Bradyville TN 37026 765-5397 tapered wing refer Figure 1 Since wings have some type wingtip other convenient square tip must approximate tip chord equations Draw theoretical square wingtip point tip area outboard theoretical tip would fill vacant areas inboard theoretical tip Extend leading edge trailing edge theoretical tip position use outline equivalent planform Note tip chord zero delta wing Terms used Figure 1 R chord T chord H span X wise location MAC S Setback tip chord sweep tip Y ack MAC models wing consists two sections MO-i can calculate MAC section combine two get MAC entire wing method shown Figure 2 subscripts used Figure 2 refer two segments 1 inboard 2 outboard make up wing W subscript refers entire wing Terms used Figure 2 X wise location MACs S wing segments Once have determined MAC wing tail neutral point determined using method Figure 3 Most terms self-explanatory tail moment arm LT used calculations distance between 25% MAC points wing tail result calculation decimal convert percent represents distance leading edge MAC neutral point distance percent MAC therefore will valid size model same configuration Ive listed approximate neutral points same aircraft appeared last column Notice neutral points almost behind midpoint MAC good flying qualities balance point CL Navy Carrier model should about 30% MAC forward neutral point static margin equal 30% MAC fuel tank forward balance point adjust balance point account fuel expect have tank end flight 30% figure will produce model will handle reasonably well Fine tuning balance point match individual preferences will require test flying should find 30% figure pretty close static margin Carlos Aloise s Profile Carrier model 33% MAC Bill Bischoffs Sniper last column has static margin 28% MAC use about 28% MO-ls well Tom Schaefers Kingfisher used 32% static margin critical dimensions relate directly MAC measured aft MAC leading edge location MAC relation rest aircraft critical accurately determining neutral point balance point etc leading edge MAC unlikely correspond leading edge root chord Balance point becomes less critical models large tail volume ratios Therefore large tail volume ratio appropriate models have large fuel tanks mounted forward balance point Thats month hope see Lubbock Keep hook dry1 IALIST IN CUSTOM COX TEE DEE & REED ENGINES 020S 049S 051S 074S & 09S ALL CUSTOM & STOCK PARTS AVAILABLE INDIVIDUALLY COMPETITION ACCESSORIES RACING WHEELS KLOTZ OIL CARBON FIBER SOLID LINES ALL KINDS OF TUBING THREE BRANDS OF GLOW PLUGS HARD-TO-FIND HARDWARE OLD TIMER SUPPLIES COILS CONDENSERS NGK & STIlT SPARK PLUGS SILK 8 COLORS QUALITY DOPE BRUSHES 5 & 7 LOOP 114 RUBBERBANDS TRANSISTOR IGNITION SYSTEMS RESISTOR HIGH TENSION LEADS 1/2A TEXACO PLAYBOY SR KIT 112A TEXACO ENGINES & PARTS RUBBER POWER KITS PROPS TISSUE AND OTHER SUPPLIES CYANOACRYLATES & EPOXIES ORDER BY MAIL OR PHONE 619 728-4365 SORRY NO COD VISA & MASTERCARD WELCOME MINIMUM MERCHANDISE ORDER $1000 SHIPPING HANDLING AND INSURANCE FEE $395 STOCK ORDERS SHIPPED WITHIN 24 HRS August1994 111 OUR REV-UP INVENTORY AVERAGES OVER 9000 PROPSIII IMMEDIATE SHIPMENT VISA/MC GOLAIR RACINU LIVES NOW YOU CAN OWN UULLCTION 15- H IAMUUb MACING PLANES OF THE 30S LIKE THE GEE BEE Z GEEFor mntt P8CI e BEE R1 HALL BULLDOG WEDELL WILLIAMS AND CAUDF1ON RACER SCHOENFELOT FIRECRACKER ALL Smilhy Dept MA HIGHLY DETAILED 1I32 SCALE KITS SEND SASE FOR ILLUSTRATED ORDER FORM $300 FOR CATALOG 1-800-345-6342Lalhe Mill Drill WILLIAMS BROS INC 181 PAWNEE ST SAN MARCOS CA 92069 3023 E 2nd SIreel Ask operalor MAThe Dalles OR 97058
Edition: Model Aviation - 1994/08
Page Numbers: 108, 109, 110, 111
CONTROL LINE NAVY CARRIER THIS MONTHS OFFERINGS include discussion balance points Carrier models bit theory support computerized scoring program Melvin Schuette NATS Special Events As announced last column Navy Carrier Society will sponsor Sportsman Profile Carrier Saturday following regular CL Navy Carrier competition flying National Aeromodeling Championships same day Dallas-area Carrier modelers will sponsor 15 Carrier eventWhen written early April sponsor Skyray Carrier Navy Carrier Society newsletter will contain latest information Nats Carrier activities Thanks Bill Bischoff rest Dallas carrier gang offering host 15 Carrier Carrier Model Selection last column promised discuss balancing Carrier models ensure acceptable handling qualities both high- low-speed flight has little written about technical aspects subject modeling magazines what has written has subject least little controversy few readers try point out errors author Having sending end some discussions past Im now embarking potentially hazardous course including such technical information own column Lest purists jump too hastily typewriters let point out intent provide simplified condensed therefore academically rigorous 100% accurate information might useful readers size location horizontal tail important determining well model can controlled low-speed flight same true high-speed flight way larger tail area located greater distance balance point would effective smaller closer horizontal tail other significant factors tail volume ratio equation length Mean Aerodynamic Chord MAC wing As MAC increases tail volume ratio control effectiveness decreases other factors remain sameThe MAC primary dimensions used stability control determinations aircraftboth models full-scale used because represents entire wings aerodynamic characteristics single airfoil fixed dimensions location Positioning balance point model logically involves locating relation wing Because MAC represents entire wing need accurately determine MAC MAC T x JJR2T 3 RT / Y H Y LEADING EDGE 5 CENTER OF LiFT RMAC25% MAC EQUAL AREAS x H figure 1 MACW MAC2X2 — x xw 2 Ii ci MAC x-x 2 DETERMINE SETBACK Y FOR MACW GRAPI-JICALLY AS SI-ION Y w MACW MAC2 figure 2 N LTST S, O N j 25 MACWNEUTRAL POINT 25% / MAC figure 3 accurately consistently position balance point model whod prefer pass up theory get right meat issue can skip next few paragraphs interested what Im writing about want complain about butchering 108 Model Aviation ge Liebs profile Wildcat Omaha Orbiting Eagles Frozen Finger Flying Festival Bob Furr photo pure~ technical aspects read aircraft fly straight level forces acting must balance same goes torque twisting moments forces produce forces moments dont balance other aircraft going change its direction motion its attitude usually both control line flying concerned primarily about pitch because force lines provides stability roll yaw spite aerodynamic forces level flight total upward force lift wing tail primarily must balance total downward force weight plus additional contribution lines whenever flying height higher control handle weight effects act balance point model lift wing tail act through point 25% aft leading edge MAC conventional aircraft tail behind wing two possible force configurations either balance point front center lift wing 25% MAC balance point behind center wing lift CL models often balance front wing center lift configuration requires downward force tail keep model balanced pitch downward tail force requires corresponding increase wing lift keep forces balanced vertically Free flight models often use balance point aft wing center lift tail can contribute total lift thus increase glide performance Both configurations can stable obviously FF models couldnt balanced Another factor stability control discussion static stability want aircraft fly hands offto keep going direction want go until make control input aircraft has positive static stability will return its initial flight conditions disturbed turbulence other factors Positive stability good aircraft has negative static stability small change attitude * * Long Engine Life * * Use BRU LINE Air Cleaner Completely Fuel Proof Nylon Rubber Parts Cat No 102 Air Cleaner Coarse $299 Cat No 202 Air Cleaner Fine $299 Replacement Inserts Cat No 104 Pkl2 Inserts Coarse $239 Cat No 204 Pkl2 Inserts Fine $239 FITS MOST ENGINES 25and UP SEE YOUR LOCAL HOBBY DEALER IF UNAVAILABLE LOCALLY SEND TO Bru Line Industries Inc P0 Box 3786 Center Line Michigan 48015 Add $250 sh pp ngM ch gan residents add 4% sales tax p p mm U IKAVI7 i Small Tool Specialists TO ORDER Send $100 ibis Brand Names. Unusual Items OVER 2000 TOOLS & ACCESSORIES IODAY IExclusive Products-many say ngs up 60% designed make prolect easier enjoyable professional INAME name address ADDRESS coupon br MicroMark340-1617 Snyder Ave L Berkely Heights NJ 07922-1595CITYSTATE ZIP r can letter mu model Simple &vd66ckae B Pressure Sensitive Water Transfer major decals 11 sizes 11 great colors RTHEAST SCREEN GRAPHICS 21 FISHER AVE EAST LONGMEADOW MA 01025 TEL 413-5254110 FAX 413-525-77R August1994 109 REICHMUTH IGNITIONS [Electronic advance systems no moving parts] complete electronics fixed mechanical advance systems Direct replacement popular systems CUSTOM COMPONENTS Reichmuth Ignitions will supply capacitor discharge spark coils circuit boards fixed electronic advance systems harness both switch Hall sensors Call write information quotes Dan Reichmuth 517 Ave D San Manuel AZ 85631 602 385-2511 Mountain Time SIG MANUFACTURING CO now imports complete line world record holding ROSSI aircraft marine helicopter race car engines includes full line parts accessories plus full time ROSSI REPAIR CENTER US SIG-imported ROSSI engines come full 90 day SIG WARRANTY against work manship manufacturing defects SIG MANUFACTURING CO INC . Montezuma IA 50171 PH 515-623-5154FAX 515-623-3922Toll Free Orders 800-247-5008 G0TOR RIC Products Inc SOFT-N-SAFE ENGINE MOUNTS Soft Mount using special serrated Iso-Damp Grommets Engine always safely retained Very effective vibration reduction dramatic decrease engine shake Light machined aluminum beam mounts 60 2-strokes 120 4-strokes available Also available aluminum radial mount 60 2-strokes Soft-N-Safe 120 beam mount complete . $3495 Soft-N-Safe 60 beam mount complete 95 SoftN-Safe 60 radial mount complete 95 Soft-N-Safe Replacement Iso-Damp Grommets Pkg 4 60$295 Pkg 4 tori 20$595 RADIAL ISO-MOUNTS Conventional backplate type mount using four Lord-Type 60-Duro IsoMounts Optimized lowest vibration transmission airframe reduced engine shake Radial Iso-mount complete $1495 Iso-Mounts Package 4 $995 5/8 diameter x 1/2 long 8-32 female end 8-32 x 1/2 male other end 60-Duro rubber TIONS -5 ----est Fuselage Provides solid support accurate building Rugged 7-ply aircraft plywood construction Two sizes available Regular fuse up 6-1/4 wide Jumbo fuse up 9-1/4 wide Use building board base mount Uni-Strut Guide Rails versatile set-up Contains hardware & instructions including Uni-Strut information Box 4 Standard Jig Stations $2195 Box 4 Jumbo Jig Stations 2395 2 Five Ft Guide Rails & Mounting Nuts . $2295 GLASS CLOTH 7 oz/Sq Yard est Filling est Weave Lightest Finished Weight Includes Detailed Instructions Big 3 Square Yard Pkg $895 R/C Products Inc 3713 Pompano Drive Pensacola FL 32514 904/494-0203 904/494-0207 VISA/MasterCard Welcomed $4 00 per item S&H esidents add 8% Tax control forces will cause aircraft divergeto continue increase its deviation original conditions Such situation obviously bad can extreme result model trying turn around fly backwards nose aircraft pitches up unintentionally because turbulence whatever lift wing tail changesboth will increase tail pushing down forward balance point tails downward force will decrease change upward force Both wing tail will experience approximately same change lift coefficient change actual lift surface proportional change lift coefficient same both wing tail times area surfaceIf balance point forward wing center lift can easily see increase lift aft balance point caused both wing tail will tend lift tail return model level flight conventional airplane positive static stability balance point can behind wing center lift case increase wing lift tends increase pitch attitude farther pitching moment product increase lift times distance wing center lift balance point increase tails lift able overcome effect because tail farther away balance point its moment lift times distance balance point greater moment caused wing As balance point moves aft will reach point pitch-up moment caused wing pitchdown moment caused tail will balance other point called neutral point neutral ground between positive negative stability key static stability handling qualities term referred static margin defined distance usually expressed percentage MAC between balance point neutral point greater static margin stable model will the elevators will have work overcome stability make model maneuver good handling qualities need positive static stabilitythe model must balance forward neutral point As static margin increases elevator control becomes less effective less sensitive achieve good stable high-speed handling qualities well good effective elevator control low-speed characteristics compromise necessary Such compromise experience places balance point about 30% MAC forward neutral point static margin equals 30% MAC static margin rather large compared full-scale aircraft reason propeller mounted front aircraft usual fashion tends make aircraft unstable powerful engines longer noses increase effect Compared full-scale aircraft engines model engines much powerful models require larger static margins compensate Enough theory make work first step determine MAC wing horizontal tail rectangular wing MAC wing chord rectangular wing swept back rather straight place MAC wing half distance centerline tip Tapered wings present little challenge much rough calculations approximation last column will suffice purists MAC lies centroid wing planform half wingcenterline tip want avoid math can draw wing half cardboard cut out determine balance point centroid cardboard Assume MAC chord passes through balance point Remember purposes wing outline extends fuselage way centerline aircraft mathematically determine MAC 110 Model Aviation R YOU DID ALL THE WORK WHY LET YOUR AIRPLANE DO ALL THE FLYING BUILD & FLY THE miniMAX YOURSELF y .omputer Designed3 Axis control Reserve Grand Champion Ultralight Part 103 Ultralight- Easy Construction 1989 Sun-N-Fun Fly-In Wood ConstructionVideoAvailable information send $500 TEAM INC 10790-MA Ivy Bluff Rd Bradyville TN 37026 765-5397 tapered wing refer Figure 1 Since wings have some type wingtip other convenient square tip must approximate tip chord equations Draw theoretical square wingtip point tip area outboard theoretical tip would fill vacant areas inboard theoretical tip Extend leading edge trailing edge theoretical tip position use outline equivalent planform Note tip chord zero delta wing Terms used Figure 1 R chord T chord H span X wise location MAC S Setback tip chord sweep tip Y ack MAC models wing consists two sections MO-i can calculate MAC section combine two get MAC entire wing method shown Figure 2 subscripts used Figure 2 refer two segments 1 inboard 2 outboard make up wing W subscript refers entire wing Terms used Figure 2 X wise location MACs S wing segments Once have determined MAC wing tail neutral point determined using method Figure 3 Most terms self-explanatory tail moment arm LT used calculations distance between 25% MAC points wing tail result calculation decimal convert percent represents distance leading edge MAC neutral point distance percent MAC therefore will valid size model same configuration Ive listed approximate neutral points same aircraft appeared last column Notice neutral points almost behind midpoint MAC good flying qualities balance point CL Navy Carrier model should about 30% MAC forward neutral point static margin equal 30% MAC fuel tank forward balance point adjust balance point account fuel expect have tank end flight 30% figure will produce model will handle reasonably well Fine tuning balance point match individual preferences will require test flying should find 30% figure pretty close static margin Carlos Aloise s Profile Carrier model 33% MAC Bill Bischoffs Sniper last column has static margin 28% MAC use about 28% MO-ls well Tom Schaefers Kingfisher used 32% static margin critical dimensions relate directly MAC measured aft MAC leading edge location MAC relation rest aircraft critical accurately determining neutral point balance point etc leading edge MAC unlikely correspond leading edge root chord Balance point becomes less critical models large tail volume ratios Therefore large tail volume ratio appropriate models have large fuel tanks mounted forward balance point Thats month hope see Lubbock Keep hook dry1 IALIST IN CUSTOM COX TEE DEE & REED ENGINES 020S 049S 051S 074S & 09S ALL CUSTOM & STOCK PARTS AVAILABLE INDIVIDUALLY COMPETITION ACCESSORIES RACING WHEELS KLOTZ OIL CARBON FIBER SOLID LINES ALL KINDS OF TUBING THREE BRANDS OF GLOW PLUGS HARD-TO-FIND HARDWARE OLD TIMER SUPPLIES COILS CONDENSERS NGK & STIlT SPARK PLUGS SILK 8 COLORS QUALITY DOPE BRUSHES 5 & 7 LOOP 114 RUBBERBANDS TRANSISTOR IGNITION SYSTEMS RESISTOR HIGH TENSION LEADS 1/2A TEXACO PLAYBOY SR KIT 112A TEXACO ENGINES & PARTS RUBBER POWER KITS PROPS TISSUE AND OTHER SUPPLIES CYANOACRYLATES & EPOXIES ORDER BY MAIL OR PHONE 619 728-4365 SORRY NO COD VISA & MASTERCARD WELCOME MINIMUM MERCHANDISE ORDER $1000 SHIPPING HANDLING AND INSURANCE FEE $395 STOCK ORDERS SHIPPED WITHIN 24 HRS August1994 111 OUR REV-UP INVENTORY AVERAGES OVER 9000 PROPSIII IMMEDIATE SHIPMENT VISA/MC GOLAIR RACINU LIVES NOW YOU CAN OWN UULLCTION 15- H IAMUUb MACING PLANES OF THE 30S LIKE THE GEE BEE Z GEEFor mntt P8CI e BEE R1 HALL BULLDOG WEDELL WILLIAMS AND CAUDF1ON RACER SCHOENFELOT FIRECRACKER ALL Smilhy Dept MA HIGHLY DETAILED 1I32 SCALE KITS SEND SASE FOR ILLUSTRATED ORDER FORM $300 FOR CATALOG 1-800-345-6342Lalhe Mill Drill WILLIAMS BROS INC 181 PAWNEE ST SAN MARCOS CA 92069 3023 E 2nd SIreel Ask operalor MAThe Dalles OR 97058
Edition: Model Aviation - 1994/08
Page Numbers: 108, 109, 110, 111
CONTROL LINE NAVY CARRIER THIS MONTHS OFFERINGS include discussion balance points Carrier models bit theory support computerized scoring program Melvin Schuette NATS Special Events As announced last column Navy Carrier Society will sponsor Sportsman Profile Carrier Saturday following regular CL Navy Carrier competition flying National Aeromodeling Championships same day Dallas-area Carrier modelers will sponsor 15 Carrier eventWhen written early April sponsor Skyray Carrier Navy Carrier Society newsletter will contain latest information Nats Carrier activities Thanks Bill Bischoff rest Dallas carrier gang offering host 15 Carrier Carrier Model Selection last column promised discuss balancing Carrier models ensure acceptable handling qualities both high- low-speed flight has little written about technical aspects subject modeling magazines what has written has subject least little controversy few readers try point out errors author Having sending end some discussions past Im now embarking potentially hazardous course including such technical information own column Lest purists jump too hastily typewriters let point out intent provide simplified condensed therefore academically rigorous 100% accurate information might useful readers size location horizontal tail important determining well model can controlled low-speed flight same true high-speed flight way larger tail area located greater distance balance point would effective smaller closer horizontal tail other significant factors tail volume ratio equation length Mean Aerodynamic Chord MAC wing As MAC increases tail volume ratio control effectiveness decreases other factors remain sameThe MAC primary dimensions used stability control determinations aircraftboth models full-scale used because represents entire wings aerodynamic characteristics single airfoil fixed dimensions location Positioning balance point model logically involves locating relation wing Because MAC represents entire wing need accurately determine MAC MAC T x JJR2T 3 RT / Y H Y LEADING EDGE 5 CENTER OF LiFT RMAC25% MAC EQUAL AREAS x H figure 1 MACW MAC2X2 — x xw 2 Ii ci MAC x-x 2 DETERMINE SETBACK Y FOR MACW GRAPI-JICALLY AS SI-ION Y w MACW MAC2 figure 2 N LTST S, O N j 25 MACWNEUTRAL POINT 25% / MAC figure 3 accurately consistently position balance point model whod prefer pass up theory get right meat issue can skip next few paragraphs interested what Im writing about want complain about butchering 108 Model Aviation ge Liebs profile Wildcat Omaha Orbiting Eagles Frozen Finger Flying Festival Bob Furr photo pure~ technical aspects read aircraft fly straight level forces acting must balance same goes torque twisting moments forces produce forces moments dont balance other aircraft going change its direction motion its attitude usually both control line flying concerned primarily about pitch because force lines provides stability roll yaw spite aerodynamic forces level flight total upward force lift wing tail primarily must balance total downward force weight plus additional contribution lines whenever flying height higher control handle weight effects act balance point model lift wing tail act through point 25% aft leading edge MAC conventional aircraft tail behind wing two possible force configurations either balance point front center lift wing 25% MAC balance point behind center wing lift CL models often balance front wing center lift configuration requires downward force tail keep model balanced pitch downward tail force requires corresponding increase wing lift keep forces balanced vertically Free flight models often use balance point aft wing center lift tail can contribute total lift thus increase glide performance Both configurations can stable obviously FF models couldnt balanced Another factor stability control discussion static stability want aircraft fly hands offto keep going direction want go until make control input aircraft has positive static stability will return its initial flight conditions disturbed turbulence other factors Positive stability good aircraft has negative static stability small change attitude * * Long Engine Life * * Use BRU LINE Air Cleaner Completely Fuel Proof Nylon Rubber Parts Cat No 102 Air Cleaner Coarse $299 Cat No 202 Air Cleaner Fine $299 Replacement Inserts Cat No 104 Pkl2 Inserts Coarse $239 Cat No 204 Pkl2 Inserts Fine $239 FITS MOST ENGINES 25and UP SEE YOUR LOCAL HOBBY DEALER IF UNAVAILABLE LOCALLY SEND TO Bru Line Industries Inc P0 Box 3786 Center Line Michigan 48015 Add $250 sh pp ngM ch gan residents add 4% sales tax p p mm U IKAVI7 i Small Tool Specialists TO ORDER Send $100 ibis Brand Names. Unusual Items OVER 2000 TOOLS & ACCESSORIES IODAY IExclusive Products-many say ngs up 60% designed make prolect easier enjoyable professional INAME name address ADDRESS coupon br MicroMark340-1617 Snyder Ave L Berkely Heights NJ 07922-1595CITYSTATE ZIP r can letter mu model Simple &vd66ckae B Pressure Sensitive Water Transfer major decals 11 sizes 11 great colors RTHEAST SCREEN GRAPHICS 21 FISHER AVE EAST LONGMEADOW MA 01025 TEL 413-5254110 FAX 413-525-77R August1994 109 REICHMUTH IGNITIONS [Electronic advance systems no moving parts] complete electronics fixed mechanical advance systems Direct replacement popular systems CUSTOM COMPONENTS Reichmuth Ignitions will supply capacitor discharge spark coils circuit boards fixed electronic advance systems harness both switch Hall sensors Call write information quotes Dan Reichmuth 517 Ave D San Manuel AZ 85631 602 385-2511 Mountain Time SIG MANUFACTURING CO now imports complete line world record holding ROSSI aircraft marine helicopter race car engines includes full line parts accessories plus full time ROSSI REPAIR CENTER US SIG-imported ROSSI engines come full 90 day SIG WARRANTY against work manship manufacturing defects SIG MANUFACTURING CO INC . 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construction Two sizes available Regular fuse up 6-1/4 wide Jumbo fuse up 9-1/4 wide Use building board base mount Uni-Strut Guide Rails versatile set-up Contains hardware & instructions including Uni-Strut information Box 4 Standard Jig Stations $2195 Box 4 Jumbo Jig Stations 2395 2 Five Ft Guide Rails & Mounting Nuts . $2295 GLASS CLOTH 7 oz/Sq Yard est Filling est Weave Lightest Finished Weight Includes Detailed Instructions Big 3 Square Yard Pkg $895 R/C Products Inc 3713 Pompano Drive Pensacola FL 32514 904/494-0203 904/494-0207 VISA/MasterCard Welcomed $4 00 per item S&H esidents add 8% Tax control forces will cause aircraft divergeto continue increase its deviation original conditions Such situation obviously bad can extreme result model trying turn around fly backwards nose aircraft pitches up unintentionally because turbulence whatever lift wing tail changesboth will increase tail pushing down forward balance point tails downward force will decrease change upward force Both wing tail will experience approximately same change lift coefficient change actual lift surface proportional change lift coefficient same both wing tail times area surfaceIf balance point forward wing center lift can easily see increase lift aft balance point caused both wing tail will tend lift tail return model level flight conventional airplane positive static stability balance point can behind wing center lift case increase wing lift tends increase pitch attitude farther pitching moment product increase lift times distance wing center lift balance point increase tails lift able overcome effect because tail farther away balance point its moment lift times distance balance point greater moment caused wing As balance point moves aft will reach point pitch-up moment caused wing pitchdown moment caused tail will balance other point called neutral point neutral ground between positive negative stability key static stability handling qualities term referred static margin defined distance usually expressed percentage MAC between balance point neutral point greater static margin stable model will the elevators will have work overcome stability make model maneuver good handling qualities need positive static stabilitythe model must balance forward neutral point As static margin increases elevator control becomes less effective less sensitive achieve good stable high-speed handling qualities well good effective elevator control low-speed characteristics compromise necessary Such compromise experience places balance point about 30% MAC forward neutral point static margin equals 30% MAC static margin rather large compared full-scale aircraft reason propeller mounted front aircraft usual fashion tends make aircraft unstable powerful engines longer noses increase effect Compared full-scale aircraft engines model engines much powerful models require larger static margins compensate Enough theory make work first step determine MAC wing horizontal tail rectangular wing MAC wing chord rectangular wing swept back rather straight place MAC wing half distance centerline tip Tapered wings present little challenge much rough calculations approximation last column will suffice purists MAC lies centroid wing planform half wingcenterline tip want avoid math can draw wing half cardboard cut out determine balance point centroid cardboard Assume MAC chord passes through balance point Remember purposes wing outline extends fuselage way centerline aircraft mathematically determine MAC 110 Model Aviation R YOU DID ALL THE WORK WHY LET YOUR AIRPLANE DO ALL THE FLYING BUILD & FLY THE miniMAX YOURSELF y .omputer Designed3 Axis control Reserve Grand Champion Ultralight Part 103 Ultralight- Easy Construction 1989 Sun-N-Fun Fly-In Wood ConstructionVideoAvailable information send $500 TEAM INC 10790-MA Ivy Bluff Rd Bradyville TN 37026 765-5397 tapered wing refer Figure 1 Since wings have some type wingtip other convenient square tip must approximate tip chord equations Draw theoretical square wingtip point tip area outboard theoretical tip would fill vacant areas inboard theoretical tip Extend leading edge trailing edge theoretical tip position use outline equivalent planform Note tip chord zero delta wing Terms used Figure 1 R chord T chord H span X wise location MAC S Setback tip chord sweep tip Y ack MAC models wing consists two sections MO-i can calculate MAC section combine two get MAC entire wing method shown Figure 2 subscripts used Figure 2 refer two segments 1 inboard 2 outboard make up wing W subscript refers entire wing Terms used Figure 2 X wise location MACs S wing segments Once have determined MAC wing tail neutral point determined using method Figure 3 Most terms self-explanatory tail moment arm LT used calculations distance between 25% MAC points wing tail result calculation decimal convert percent represents distance leading edge MAC neutral point distance percent MAC therefore will valid size model same configuration Ive listed approximate neutral points same aircraft appeared last column Notice neutral points almost behind midpoint MAC good flying qualities balance point CL Navy Carrier model should about 30% MAC forward neutral point static margin equal 30% MAC fuel tank forward balance point adjust balance point account fuel expect have tank end flight 30% figure will produce model will handle reasonably well Fine tuning balance point match individual preferences will require test flying should find 30% figure pretty close static margin Carlos Aloise s Profile Carrier model 33% MAC Bill Bischoffs Sniper last column has static margin 28% MAC use about 28% MO-ls well Tom Schaefers Kingfisher used 32% static margin critical dimensions relate directly MAC measured aft MAC leading edge location MAC relation rest aircraft critical accurately determining neutral point balance point etc leading edge MAC unlikely correspond leading edge root chord Balance point becomes less critical models large tail volume ratios Therefore large tail volume ratio appropriate models have large fuel tanks mounted forward balance point Thats month hope see Lubbock Keep hook dry1 IALIST IN CUSTOM COX TEE DEE & REED ENGINES 020S 049S 051S 074S & 09S ALL CUSTOM & STOCK PARTS AVAILABLE INDIVIDUALLY COMPETITION ACCESSORIES RACING WHEELS KLOTZ OIL CARBON FIBER SOLID LINES ALL KINDS OF TUBING THREE BRANDS OF GLOW PLUGS HARD-TO-FIND HARDWARE OLD TIMER SUPPLIES COILS CONDENSERS NGK & STIlT SPARK PLUGS SILK 8 COLORS QUALITY DOPE BRUSHES 5 & 7 LOOP 114 RUBBERBANDS TRANSISTOR IGNITION SYSTEMS RESISTOR HIGH TENSION LEADS 1/2A TEXACO PLAYBOY SR KIT 112A TEXACO ENGINES & PARTS RUBBER POWER KITS PROPS TISSUE AND OTHER SUPPLIES CYANOACRYLATES & EPOXIES ORDER BY MAIL OR PHONE 619 728-4365 SORRY NO COD VISA & MASTERCARD WELCOME MINIMUM MERCHANDISE ORDER $1000 SHIPPING HANDLING AND INSURANCE FEE $395 STOCK ORDERS SHIPPED WITHIN 24 HRS August1994 111 OUR REV-UP INVENTORY AVERAGES OVER 9000 PROPSIII IMMEDIATE SHIPMENT VISA/MC GOLAIR RACINU LIVES NOW YOU CAN OWN UULLCTION 15- H IAMUUb MACING PLANES OF THE 30S LIKE THE GEE BEE Z GEEFor mntt P8CI e BEE R1 HALL BULLDOG WEDELL WILLIAMS AND CAUDF1ON RACER SCHOENFELOT FIRECRACKER ALL Smilhy Dept MA HIGHLY DETAILED 1I32 SCALE KITS SEND SASE FOR ILLUSTRATED ORDER FORM $300 FOR CATALOG 1-800-345-6342Lalhe Mill Drill WILLIAMS BROS INC 181 PAWNEE ST SAN MARCOS CA 92069 3023 E 2nd SIreel Ask operalor MAThe Dalles OR 97058