Radio Control: Aerobatics

RADIO CONTROL AEROBATICS IF WERE TO pick ten pilots judges average Aerobatics contest ask what single maneuver family generates argument controversy sport am certain least nine would answer hesitating snap rolls tenth would say spins mostly same maneuvers done slightly different way Im willing bet ten answers would announced forcefully accompanied jutting jawlines full eyecontact unspoken invitation disagree peril almost religious aura attached peoples opinions matters aerobatic comes snaps spins aura changes fervor socalled opinions incontrovertible fact nine ten would name same maneuver would seem indicate least minor amount agreement subject fact what minor amount problem nine might say snap rolls nine might have rock-hard opinions exactly what good snap roll should nine opinions will different fact chances finding identical opinions subject average gathering Aerobatics cognoscenti slightly less chances hitting lottery surviving airliner crash same day some reasons Pattern structured individual pursuit pilot judges attracts people like think themselves rise fall own merits compete Generally speaking sort people reach agreement easily modify cherished beliefs simply avoid confrontation another age would have referred rugged individualists prefer simply pigheaded insert noun choices FAI AMA rule books describe execution snaps rolls spins general ambiguous terms judging criteria provided extraordinarily subjective nature Room has left honest opinions conflict great deal predictably have done lessthan-admirable job rule-writing AMA FAI levels emotion point heated because isnt trivial matter Contests won lost application conflicting opinions Few us possess nobility lose well cannot agree judges interpretation rulesespecially interpretation leads directly zero high K maneuver ruined round same token few judges possess forbearance tolerate competitors heated protest score know right whether disagreement directed properly contest management Fixing such wide-spread problem isnt easy would have accomplished long time ago same fixing worthwhile goal aim friendly competition should maximum fun minimum fuss Nowadays people have great deal choice spend leisure time Angry Aerobatics competitors judges often choose participate future events absence diminishes sport doesnt mean must fix little flaw set Pattern bone contention fortunate because isnt possible Disagreement will always us see paragraph above average Pattern competitors personality profile would vanilla-bean world everyone always same page However single snap/spin flash point responsible such high percentage most-destructive bickering makes very little sense continue ignoring hopes some magical means agreement will eventually emerge easiest way fix whole mess would simply ban snaps spins isnt option whole roomful reasons boil down would cop out Snaps spins legitimate aerobatic maneuvers belong Pattern competition Before get possible fixes need take look what makes controversial maneuvers tick since maneuvers werent invented RC modelers should go source full-scale aerobatics basic horizontal inside snap roll really spin done level flight Autorotation induced difference drag lift between in-snap in-spin wing inside rotation out-snap out-spin outside rotation wing start horizontal snap upright spin aircraft pitched up until critical AOA angle attack exceeded whereupon hard rudder applied desired direction rotation resulting yaw decelerates inside wing accelerates outside wing slowing inside wing produces less lift yes some lift still exists past critical AGA accelerating outside wing produces thus producing autorotation roll component along longitudinal roll axis As autorotation starts inside wing AOA increases thus produces drag outside wing AOA decreases produces less drag because shift relative wind airflow wing sees 96 Model Aviation f Combs Integra design 1998 Nats Fixed gear two-meter scalelike design follows new F3A trends Geoff Pickerington Ohio F3A competitor Don Szczur Chantilly VA relaxes Dr Jekyll 1998 Nats wide variance basic knowledge Unfortunately pilot-to-pilot grapevine also spawns various myths passed fact until harden like yesterdays cheeseburger coronary artery Myth Number application aileron has no place proper snap spin truth application alleron usually small varying good deal aircraft type direction rotation rule full-scale competitive arena done same reason model aerobats accelerate rotation further increasing difference AOA between inside Texan Todd Blase hand-flies F3A finals sequence 98 Nats caller BWoutside wings Too much aileron will produce Ponder waits shawtime model Blase-designed Associationonly drag actually slow rotation second major myth once elevator applied commence stall snap control position never modtfied until recovery lest aircraft unstall barrel around truth once rotation commences forward stick usually applied instantly point critical AOA just barely exceeded keep burying snap elevator quickly backed out little clean up maneuver accelerate rotation because rotation effect felt along vertical yaw axis additive rotation increases obvious snap because entry speed higher stall entry accelerated aircraft continuing along its original horizontal flight path because mass inertia main difference between entries two maneuvers snap entry speed higher elevator movement abrupt enough critical AOA exceeded almost instantly causing accelerated stall little deviation aircraft track spin aircraft slowed pitch-up past critical AOA gradual stall accomplished direction flight changes near-vertical down line autorotation commences above fairly basic full-scale aerobatic information somewhat simplified understandable consumption has rarely seen modeling literature Ive reviewed during last several decades have what anthropologist would refer oral tradition subject What RC modelers Pattern pilots know about spins snaps control sticks model does looks certain way basic knowledge comes instructors peers own experimentation outside reading may may have done Since everyones experience different respect small wonder opinions differ much bad enough hit-and-miss approach aerobatic education produces such April 1999 97 Weve got number 11 sizes 11 great colors pressure sensitive & water transfer 4OO & o44 po* CkOA GRAPHICS PO BOX 304orn,. MA 01028 TEL 413-525-4110 FAX 413525779 called unloading snap especially critical technique snaps vertical line snap maneuver exit speed energy must remain high Buiying snap aerobatic slang exceeding critical AOA during maneuver point planform drag becomes excessive too much energy lost happens snap rotation slowed exit airspeed low causes aircraft fall out recovery far common snap roll fault aerobatic arena full-scale model common need spend little time idea Most RC pilots have never heard term no specific downgrade exists yet sit judges chair well excess half snaps see buried point portion maneuver following snap roll proper well-nigh ruinedwhich definitely causes some downgrading take place Some because pilots dont realize have choice throwing sticks corner nailing stops way know perform maneuver Some because snaps done button way too much elevator programmed mix unfortunately some because unloading snap properly can cause maneuver look too clean axial directional satisfy judges some fellow competitors because own ignorance prejudices passed others actually looking buried snap Unless model loses great deal speed energy flailing around like airborne train wreck exits 150 off heading arbiters acrobatic bad taste arent convinced so-called break has occurred model has actually autorotated last problem isnt confined realm RC Aerobatics found following quote late former World Aerobatic Champion Leo Loudenslager writing 1995 US Aerobatic Champion Mike Goulians Geza Szuroys excellent book Advanced Aerobatics McGraw-Hill World Championship flying Laser maneuver outside snap roll inverted inverted climbing 450 line hit maneuver perfectly Back ground fellow competitor stated some frustration maneuver either 10 zero incident illustrates what can run doing perfect snap roll competition Anybody doesnt find Leos words very familiar simply hasnt flying competition Aerobatics very long Spins another case point Most arguments center around entry whether model snapped spin perhaps flown through entry no stall break Some perhaps disagreements direct result ambiguously written rulesbut some again result prejudice us have iron clad mental picture what aircraft should look like stalls spins what see doesnt fit mental mold rejected downgraded Since factors enter way different designs spin FAI AMA books contain admonishments judge disregard attitude model long stalled year judge fly front people have either never read rule have decided own ideas take precedence Addressing problems will take multifaceted approach need revise rules improve pilot judge education Neither will easy have few suggestions rules side equation snap spin rules appear current AMA Competition Regulations lifted virtually intact FM book know because responsible doing about decade back may take word done align both books same traditional standnrdnot because FM maneuver definitions perfectly written 1990 FM Sporting Code cribbed stated snap roll rapid autorotative roll model stalled attitude bit further statement appeared . attitude flight path must show definite break before rotation started stall does occur model barrel-rolls around manoeuvre zeroed believe current rules identical points spins same ultra-spare approach applies FM rules order spin model must stalled entry flown near horizontal path nose up attitude increasing speed decreases nose drops model stalls Simultaneously wing drops direction spin model does stall model snaprolled spin manoeuvre zeroed AMA book follows both definitions closely leaves out FM snap requirement definite break before rotation started stating attitude flight path must show definite break done because people myself included felt still feel FAT requirement break before rotation commences totally unjudgeable modelscale 150-175 meters benefit stop-action slow-motion photography Sporting Code also lists judging criteria snap rolls must maintain constant flight path through manoeuvre No could explain just exactiy what statement meant suspect means during snap rotation center gravity model must follow roughly along track projected line entry maneuver doesnt state does left out AIvIA book As result regardiess whether AMA FM book used pilot gets little help definition judge gets less People operating opinion subjective impression Well looked like snap roll ause have given sorts room exactly AMA judging video absolutely excellent other areas isnt help rule book snaps spinsbecause definitions used same taken word word FM book turn lifted FM fullscale aerobatic rules possibly eons ago weight particular tradition immense fact may original grandfather clause What needed definitive rewrite ancient vague rulesone answers big questions addresses gray areas Most importantly rules definitions should written idea judgeability mind must give judge hook hang score let pilot know exactly what required since FM appears locked adherence nonfunctioning tradition need AMA Competition Regulations isnt necessary convince rest world effect change example take matter snap roll entry spin snap roll entry defined taking place up-going wing exceeded vertical plane past 900 rotation roll axis before nose dropped below horizontal plane defined entry track judge would have hard-and-fast criterion go pilot would have rule live would no doubts no problems no room opinion no arguments Similar approaches could taken clearing up other snap/spin questions Instead rapid autorotative roll perhaps could use precise requirement such minimum 3600/second rotation characteristics barrel roll aircraft actually flown around small loop constant G track Center Gravity aircraft supposedly being snaprolled described half-wingspan visible circle flight path maybe could define barrel roll end some arguments Instead loose requirement break snap roll definition might contain requirement simultaneous divergence demonstrated pitch roll yaw axes spin requirements nearly horizontal nearly vertical entry exit paths could reworked specific allowable angular deviation perhaps five 10 degrees very likely can think other problems similar solutions along lines dont pretend possible solutions Ive suggested best ways solve problems merely intended show possible write accurate specific requirements something can ancient problems weve inherited dont have continue exist least AMA Pattern should solve move new ones Thats called progress around its traditional well odel Aviation