RADIO CONTROL SCALE AEROBATICS received three letters concerning use inaccurate commonly used term weathervane April column describe yawing occurs during crosswind maneuvers case discussion about crosswind landings favorite Bob Zajichek Issaquah Washington Excerpts follow Although cant consider myself outstanding RC pilot 25 years military flyingmostly carrier aircraft pet peeves almost eight years Ive struggled RC flight has consistent misuse terms weathervaning weathercocking students instructors wind does cause airplane weathervane rather pilot unconsciously points nose wind order fly desired flight path over ground using crab method drift correction airplane balanced flight wings level controls neutralized What Mr Hawkinson describes arc two methods drift correction crab slip crab used maintain flight path over ground balanced flight condition slip lines longitudinal axis landing gear up flight path upwind wing lowered downwind rudder applied keep airplane turning Because slipping difficult its frequently applied just prior touchdown Tricycle geared aircraft can landed either crab slip condition because center gravity CG forward main mounts airplane tends track straight down landing line after touchdown Tail-draggers present problem CC aft main mounts longitudinal axis lined up landing line inertia will tend swing tail forward cause ground loop landing Therefore its best land tail dragger upwind wing low One-wheel landings much preferred over landing crab worse yet drifting downwind Two final points 1 Weathervaning occurs airplane ground Once its air airplane moves right air mass its crab balanced flight condition maintain desired flight path Lets start using correct terminology 2 Ground handling strong wind can trickyparticularly trainers lots dihedral RC pilots should learn taxi takeoff just pilots full-scale aircraft Keep aileron wind reduce possibility wind raising upwind wing As airplane picks up speed ailerons become effective during takeoff roll ease off amount aileron fly off-wing-low turn wind establish crab Also holding full down elevator taxiing tail-dragger downwind can increase pressure tail wheel course Mr Zajichek correct doesnt change single thing about go about learning fly perfect crosswind approach Ill try use more-accurate terminology Theres no doubt Ill make similar mistakes future since alleged writing style consciously intended compact possible conveying information Another example term commonly applied describe two-stroke engine running very rich four-cycling Weathervaning occurs airplane ground Lets start using correct terminology obvious misnomer instantly understood hobby two other letters subject contained old saw about airplane doesnt know wind blowing also true humble opinion its useless truism sport airplane doesnt know missed runway endangered spectator removed its landing gear either However ignorant actual aircraft may pilotand other things Earths surfacecertainly recognize path flight decidedly different depending wind conditions relative fixed perspective pilot others ground RC full-scale pilots recognize different control inputs required differing wind conditions discussion leads nicely another subject Ive received several letters about What difference between Scale Aerobatics Precision Aerobatics Pattern first obvious difference Scale Aerobatics requires fly Scale airplane normally replica full-scale aerobatic aircraft non-contest purposes thats really wondering about competition answer bit involved Pattern allows aircraft engine long weight no five kilograms 11 pounds dimensions exceed two meters approx 7875 inches span length noise levels aiso limited Pattern 96 decibels three meters over pavement Scale airplanes common Pattern contests certainly can used sometimes areespecially lower classes competition Scale Aerobatics IMAC contests require semiscale aircraft except rules allow non-Scale models CDs discretion Basic class Size limited except general AMA limits RC modelswhich means can fly pretty darn large aircraft also no prohibition against electronic mechanical aids such gyros published IMAC rules may recall though some CDs outlaw such devices contests terms flying lot similarities between Pattern IMAC maneuvers identical course control inputs required fly four-point roll same no matter what type aerobatics prefer however some pretty notable differences way two events flown Lets look big ones first thing youll notice takeoff landing maneuvers scored IMAC events AMA Pattern scored maneuvers either event obviously required maneuvers Youll find emphasis IMAC geometry prototypical maneuvering no mention smoothness IMAC rules Pattern smoothness second precision determining quality thus score maneuver notable rolling maneuvers IMAC style aggressive quick aileron inputs IMAC events often fly sequences two per flight higher-scoring sequence recorded lower score dropped Landing minor adjustments between sequences allowed Pattern scores counted majority flights best three four flights best four scores five six flights completed very big difference between IMAC Pattern IMAC events have option flying Unknown sequences Freestyle class Unknowns group maneuvers have selected knowledgeable pilot handed out day prior being flown Pilots allowed practice sequence before competition obviously added challenge individual maneuvers comfortable pilot order maneuvers will require differing technique Unknown sequences used flown addition instead regular published sequences Sportsman Advanced Unlimited Three-Minute Freestyle class hotdog display judged originality versatility harmony rhythm execution terms sound rather subjective well class favorite spectators pilots always hotly awaited portion Tournament Champions event Pilots may usually fly August1998 121 Easy hand starts Slower smoother idle & mid-range Lightweight- 3 05 less battery pack Better top end power Easy install achining wiring required Can installed minutes hand tools electronic parts installed small wggeax 1 5/8 x 1 3/16 No moving parts wear out get out adjustment new igniweight machined aluminum flywheel Timing adjustable few degrees fine tune engineworsrs% have complete ignition systems MoCulloch Ryobi~St5IIing weed eater engines accessories parts available ignition enaine Custom installation available regular class Freestyle event contest next very big difference between Pattern IMAC concerns wind-correcting told connected crosswindlanding stuff Pattern pilot always required correct track flight no matter what aircraft attitude required maintain track things makes Pattern challenging strong wind its common see Pattern airplane flying very severe crab angles order keep track true especially aircraft slows top stall turn IMAC rules path-correcting actually prohibited vertical lines quote 90degree lines graded angle fuselage relation ground other lines judged track flight path aircraft Thus wind IMAC airplane will moved downwind during instance stall turn humpty bump relative us earth complicated result rules vertical 90-degree lines required corrected thus humpty bump entry exit half-loop supposed wind-corrected up- down-lines allowed wind-corrected last difference Ill note very minor probably causes questions other differences Namely LIVIAC crowd tends refer Stall Turns normal Pattern description Hammerheads same maneuver except way wind dealt noted above want fly either event hope you should order Competition Regulations AMA Headquarters study event often thoroughly true dont intend actually compete dont afraid fly both types aerobaticsmany us Both events require precision flying thats what makes us improve skills Wrigley Way Milpitas California 95035 Voice/Fax 408 946-4751 408 WINGS-S 1 cW PRODUCTS LOOK no further fully molded sailplane needs RnR offer selection high performance sailpianes will address specific requirements F3BThermal Duration Slope Cross Country Mark Allen designed World Championship F3B EAGLE now being produced RnR its new lower price RnR sailplane enjoys design construction enhancements 1997 RoRs composite molded technology provides unique blend strength weight optimization Noticeable results found through increased durability torsional stability stiffness incorporated wing fuselage tail section also offer selection parts joiner systems scratch builders Out catch latest visuals specifications competitive pricing RnRs sailplanes contact RnR RnR skys limit. 122 Model Aviation J ELECTRONICS 1236 Marigold St NW Hartville OH 44632 330-877-1445 f Service & Repairs Most Radio Control Systems Utilizing Calibrated Test Equipment & Spectrum Analyzers Endors.d AMA RCMA Sticker Station l05 Futaba Airtronics JR Ace HiTec Tower Cirrus World Engines & WE USE GENUINE FACTORY REPLACEMENT PARTS Complete 1991 Narrow Banding & Upgrades RCD / HITEC R/C DEALER FCC IicensedSpeed Control RepairsQuality ServiceFast Turn Around Shipping & Insurance ExtraUPSU S MailCODs _ VISAIFM w w Visit home pats hllp//wmmdnjelectronicscom Email davId@dnlslectronicscom ayne@dnjelsctronits AMA #256123ARRLWB8YSQ
Edition: Model Aviation - 1998/08
Page Numbers: 121, 122
RADIO CONTROL SCALE AEROBATICS received three letters concerning use inaccurate commonly used term weathervane April column describe yawing occurs during crosswind maneuvers case discussion about crosswind landings favorite Bob Zajichek Issaquah Washington Excerpts follow Although cant consider myself outstanding RC pilot 25 years military flyingmostly carrier aircraft pet peeves almost eight years Ive struggled RC flight has consistent misuse terms weathervaning weathercocking students instructors wind does cause airplane weathervane rather pilot unconsciously points nose wind order fly desired flight path over ground using crab method drift correction airplane balanced flight wings level controls neutralized What Mr Hawkinson describes arc two methods drift correction crab slip crab used maintain flight path over ground balanced flight condition slip lines longitudinal axis landing gear up flight path upwind wing lowered downwind rudder applied keep airplane turning Because slipping difficult its frequently applied just prior touchdown Tricycle geared aircraft can landed either crab slip condition because center gravity CG forward main mounts airplane tends track straight down landing line after touchdown Tail-draggers present problem CC aft main mounts longitudinal axis lined up landing line inertia will tend swing tail forward cause ground loop landing Therefore its best land tail dragger upwind wing low One-wheel landings much preferred over landing crab worse yet drifting downwind Two final points 1 Weathervaning occurs airplane ground Once its air airplane moves right air mass its crab balanced flight condition maintain desired flight path Lets start using correct terminology 2 Ground handling strong wind can trickyparticularly trainers lots dihedral RC pilots should learn taxi takeoff just pilots full-scale aircraft Keep aileron wind reduce possibility wind raising upwind wing As airplane picks up speed ailerons become effective during takeoff roll ease off amount aileron fly off-wing-low turn wind establish crab Also holding full down elevator taxiing tail-dragger downwind can increase pressure tail wheel course Mr Zajichek correct doesnt change single thing about go about learning fly perfect crosswind approach Ill try use more-accurate terminology Theres no doubt Ill make similar mistakes future since alleged writing style consciously intended compact possible conveying information Another example term commonly applied describe two-stroke engine running very rich four-cycling Weathervaning occurs airplane ground Lets start using correct terminology obvious misnomer instantly understood hobby two other letters subject contained old saw about airplane doesnt know wind blowing also true humble opinion its useless truism sport airplane doesnt know missed runway endangered spectator removed its landing gear either However ignorant actual aircraft may pilotand other things Earths surfacecertainly recognize path flight decidedly different depending wind conditions relative fixed perspective pilot others ground RC full-scale pilots recognize different control inputs required differing wind conditions discussion leads nicely another subject Ive received several letters about What difference between Scale Aerobatics Precision Aerobatics Pattern first obvious difference Scale Aerobatics requires fly Scale airplane normally replica full-scale aerobatic aircraft non-contest purposes thats really wondering about competition answer bit involved Pattern allows aircraft engine long weight no five kilograms 11 pounds dimensions exceed two meters approx 7875 inches span length noise levels aiso limited Pattern 96 decibels three meters over pavement Scale airplanes common Pattern contests certainly can used sometimes areespecially lower classes competition Scale Aerobatics IMAC contests require semiscale aircraft except rules allow non-Scale models CDs discretion Basic class Size limited except general AMA limits RC modelswhich means can fly pretty darn large aircraft also no prohibition against electronic mechanical aids such gyros published IMAC rules may recall though some CDs outlaw such devices contests terms flying lot similarities between Pattern IMAC maneuvers identical course control inputs required fly four-point roll same no matter what type aerobatics prefer however some pretty notable differences way two events flown Lets look big ones first thing youll notice takeoff landing maneuvers scored IMAC events AMA Pattern scored maneuvers either event obviously required maneuvers Youll find emphasis IMAC geometry prototypical maneuvering no mention smoothness IMAC rules Pattern smoothness second precision determining quality thus score maneuver notable rolling maneuvers IMAC style aggressive quick aileron inputs IMAC events often fly sequences two per flight higher-scoring sequence recorded lower score dropped Landing minor adjustments between sequences allowed Pattern scores counted majority flights best three four flights best four scores five six flights completed very big difference between IMAC Pattern IMAC events have option flying Unknown sequences Freestyle class Unknowns group maneuvers have selected knowledgeable pilot handed out day prior being flown Pilots allowed practice sequence before competition obviously added challenge individual maneuvers comfortable pilot order maneuvers will require differing technique Unknown sequences used flown addition instead regular published sequences Sportsman Advanced Unlimited Three-Minute Freestyle class hotdog display judged originality versatility harmony rhythm execution terms sound rather subjective well class favorite spectators pilots always hotly awaited portion Tournament Champions event Pilots may usually fly August1998 121 Easy hand starts Slower smoother idle & mid-range Lightweight- 3 05 less battery pack Better top end power Easy install achining wiring required Can installed minutes hand tools electronic parts installed small wggeax 1 5/8 x 1 3/16 No moving parts wear out get out adjustment new igniweight machined aluminum flywheel Timing adjustable few degrees fine tune engineworsrs% have complete ignition systems MoCulloch Ryobi~St5IIing weed eater engines accessories parts available ignition enaine Custom installation available regular class Freestyle event contest next very big difference between Pattern IMAC concerns wind-correcting told connected crosswindlanding stuff Pattern pilot always required correct track flight no matter what aircraft attitude required maintain track things makes Pattern challenging strong wind its common see Pattern airplane flying very severe crab angles order keep track true especially aircraft slows top stall turn IMAC rules path-correcting actually prohibited vertical lines quote 90degree lines graded angle fuselage relation ground other lines judged track flight path aircraft Thus wind IMAC airplane will moved downwind during instance stall turn humpty bump relative us earth complicated result rules vertical 90-degree lines required corrected thus humpty bump entry exit half-loop supposed wind-corrected up- down-lines allowed wind-corrected last difference Ill note very minor probably causes questions other differences Namely LIVIAC crowd tends refer Stall Turns normal Pattern description Hammerheads same maneuver except way wind dealt noted above want fly either event hope you should order Competition Regulations AMA Headquarters study event often thoroughly true dont intend actually compete dont afraid fly both types aerobaticsmany us Both events require precision flying thats what makes us improve skills Wrigley Way Milpitas California 95035 Voice/Fax 408 946-4751 408 WINGS-S 1 cW PRODUCTS LOOK no further fully molded sailplane needs RnR offer selection high performance sailpianes will address specific requirements F3BThermal Duration Slope Cross Country Mark Allen designed World Championship F3B EAGLE now being produced RnR its new lower price RnR sailplane enjoys design construction enhancements 1997 RoRs composite molded technology provides unique blend strength weight optimization Noticeable results found through increased durability torsional stability stiffness incorporated wing fuselage tail section also offer selection parts joiner systems scratch builders Out catch latest visuals specifications competitive pricing RnRs sailplanes contact RnR RnR skys limit. 122 Model Aviation J ELECTRONICS 1236 Marigold St NW Hartville OH 44632 330-877-1445 f Service & Repairs Most Radio Control Systems Utilizing Calibrated Test Equipment & Spectrum Analyzers Endors.d AMA RCMA Sticker Station l05 Futaba Airtronics JR Ace HiTec Tower Cirrus World Engines & WE USE GENUINE FACTORY REPLACEMENT PARTS Complete 1991 Narrow Banding & Upgrades RCD / HITEC R/C DEALER FCC IicensedSpeed Control RepairsQuality ServiceFast Turn Around Shipping & Insurance ExtraUPSU S MailCODs _ VISAIFM w w Visit home pats hllp//wmmdnjelectronicscom Email davId@dnlslectronicscom ayne@dnjelsctronits AMA #256123ARRLWB8YSQ