航空专英1教案第5章ForcesinFlight

Ch.5Stabilityandcontrol

5.1Balanceandtrim

1,balanceinstraightandlevelflight

balance平篌亍see-saw杠杆bean梁

woodenbean木梁suspendedbean悬吊梁fulcrum支点

trim配平equilibrium平衡

controlcolumn才桑纵才干rudderpedal方向舵脚蹬

align,alignment成一直线

Figure2.2-1See-saw.

Figure2.2-2

Unbalanced

Figure2.2-3

Rebalanced

Figure2.2-4Rebalanced

Balanceconsistsoftwoelements-thetotalforcesactingthe

aircraftandthealignmentoftheseforces.Whentheforcesare

balancedandalignedtheaircraftissaidtobeinequilibrium.

Therearetwotypesofforces-staticforces,dynamicforces.

Weightisastaticforceitcanbeconsideredconstantatanytime.

Thrustvarieswithenginepower,propellerrpmandairspeedbut

canbesetataconstantvaluebythepilot.

Liftisaerodynamicforcewhichchangeswithairspeedandflap

extensionbutwhichcanbecontrolleddirectlybythepilotchanging

theangleofattack.

Dragchangeswithangleofattack,configurationandairspeed.

♦LLift(2,000units)

T:

hrust(200units)；：「『二""brag(200units)

WWeight(2,000units)

Figure2.2-7

Liftbalancesweight.

3ndthrustbalancesdrag,instraightandlevelflight.

Instraightandlevelflight,liftopposesweightL=Wthrust

opposesdragT=D.

Theliftandweightwillonlydecreasegraduallyastheweight

decreaseswithfuelburn-off.Thethrustanddragwillvary

considerablydependingonangleofattackandthereforeairspeed.

2,pitchingmoment

Lift-

Nose-down

CGCP

Weighty

LiftAk

Weighty

Figure2.2-8

Lift-weightcouple

producesapitchingmoment.

Nose-upThrust

WNose-down

Figure2.2-9Thrust-dragcoupleproducesapitchingmoment

UndermostconditionsofflighttheCPandCGarenotcoincident,

i.e.arenotattheonepoint,causingnose-downpitchingmomentora

nose-uppitchingmoment.

Thedifferentlinesofactionofthethrustforceanddragforce

produceanothercouple,causinganose-downpitchingmomentora

nose-uppitchingmoment.

Ideallythepitchingmomentfromthetwocouplesshould

neutralizeeachotherinlevelflightsothatthereisnoresultant

momenttendingtorotatetheaircraft

ALift

Thrust-drag

couple

nose-up

Lift-weightFigure2.2-10

coupleLift-weightcoupleandthri

nose-downdragcoupleinequilibrium.

Weight▼

Figure2.2-11Verticallyoffsetthrustline

ALift

Thrust-drag

Thrusl-dragcouple

Icouple(Reduced

(nose-upnose-up

moment)moment)

▼Thrust

Lift-weigh!

couple

(nose-down

moment)Lift-weight

couple

(nose-down

Weight▼moment)

Figure2.2-12Followingalossofthrust,thelift-weightcouple,

3,thetailplane

horizontalstabilizer水平安定面

function功能，作用counteract平衡，中和

residual剩余的,neutralize抵消

coincident一致

Thrust

Balancing

aerodynamicforce

Weight''059EPS

Figure2.2-13

Thetailplaneprovidesthefinalbalancingmoment.

Thefunctionoftailplane(orhorizontalstabilizer)istocounteract

theseresidualpitchingmomentsfromthetwomaincouplesandto

dampedanyoscillationinpitch,i.e.ithasastabilizingfunction.

Thetailplaneusuallyhasasymmetricaloranegativelycambered

aerofoil.

Themomentproducedbythetailplanecanbevariedeitherby

movingtheelevatororbymovingtheentiretailplane.

Themomentarmoftailplaneisquitelong,andtheaerodynamic

forceprovidedbythetailplaneneedsonlytobesmalltohavea

significantpitchingeffect.

Theareaofthetailplaneissmallcomparedwiththemainplanes

(mainwings).

5.2Stability

Therearetwoelementsofstability,staticanddynamic,andforan

aircraft,itisusualtoseparatethemodesintothethreeaxesof

movement.

Thereislongitudinalstability,lateralstabilityanddirectional

stability.

Thereisaninseparablerelationshipbetweenlateraland

directionalstability.

5.2.1Staticstabilityanddynamicstability

1,Staticstability

Oscillation

Disturbed

Released

Figure2.2-14Staticanddynamicstability

Thestaticstabilityoftheaeroplanedescribesitstendencyto

returnitsoriginalcondition(angleofattack)afterbeingdisturbed

andwithoutanyactionbeingtakenbythepilot.Thestrengthofthe

tendencyisthemeasureofitsstability.

2,Dynamicstability

remove取消，去除deadbeat非周期的，无振荡的

indefinitely无限地divergent发散

shortperiod短周期，longperiod,phugoid长周期，

Dynamicstabilityisconcernedwiththemotionofthebodyafter

thedisturbingforcehasbeenremoved.

Itisanoscillationwhichmaystopimmediately(well-dampedor

deadbeat),continuebutreduceslowly(slightlyorlightlydamped),

continueindefinitely(undamped)orgetworse(dynamically

unstableordivergentoscillation).

Imaginetheaircraftistrimmedinstraightandlevelflight,the

aircraftwillrespondtotheverticalgustbypitchingdownto

maintainitstrimmedangleofattack.

Thisoscillationisgenerallywell-dampedandreducestozeroin1

or2oscillation.Thedampingisprovidedbytheaironthehorizontal

areaoftheaircraft.Thepitchingoscillationisknownastheshort

periodpitchingoscillation(SPPO).

Theairspeedoftheaircraftmayalsochangeandthiscancausea

slower(longperiod)oscillationwheretheaircraftleisurely(慢慢

地)followsapathwheretheairspeedandaltitudeareexchanged.

Theslowmotioniscalledthephugoid.

3,thethreereferenceaxes

Centreof

gravity(CG)

Normal

(verticalaxis)

WAEFS

Figure2.2-15

Angularmotioncanoccuraboutthreeaxes.

Werefer。三类)themotionoftheaircrafttomotionabouteachof

threeaxes-eachpassingthroughthecentreofgravityandeach

mutuallyperpendicular(at90°toeachother).Thesearesometimes

calledbodyaxes.

Figure2.2-16Rollingaboutthelongitudinalaxis.

Figure2.2-17Pitchingaboutthelateralaxis.

Yawingplane

ofmotion

Figure2.2-18Yawingaboutthenormalaxis.

Stabilityaroundthelongitudinalaxisisknownaslateralstability.

Stabilityaroundthelateralaxisisknownaslongitudinalstability.

Stabilityaroundthenormalaxisisknownasdirectionalstability.

Rotationaroundapointoraxisiscalledangularmotion;the

numberofdegreesofrotationiscalledangulardisplacement,andthe

speedwithwhichitoccurs,angularvelocity.

Themotionofanaircraftisbestconsideredineachoftheplanes

separately,althoughtheactualmotionoftheaircraftisalittlemore

complex.Forexamplepollingintoalevelturntheaircraftwillnot

onlyrollbutalsopitchandyaw.

Wewillconsiderlongitudinalstabilityfirst,thendirectional

stabilityandlateralstability.Rollandyawarecloselyconnected.

5.2.2Longitudinalstability

inbuilt固有的，内在的，dart飞镖，arrow箭

Tobelongitudinalstable,anaircraftmusthaveanaturalorinbuilt

tendencytoreturntothesameangleofattackafteranydisturbance

withoutanycontrolinputbythepilot.

Iftheangleofattackissuddenlyincreasedbyadisturbance,then

forcewillbeproducedthatwilllowerthenoseanddecreasethe

angleofattack.

1,thetailplaneandlongitudinalstability

RestoringNose-down

aerodynamicpitchingmoment

Figure2.2-20Longitudinalstabilityfollowingan'uninvited'nose-uppitch.

Gust

Nose­

down

Figure2.2-21Longitudinalstabilityfollowingan,unmvited,nose-downpitch.

Ifadisturbance,suchasagust,changestheattitudeoftheaircraft

bypitchingitnoseup,thetailplanewillbepresentedtotherelative

airflowatagreaterangleofattack.Thiswillcausethetailplaneto

produceupward,ordecreased,aerodynamicforce,whichisdifferent

tothatbeforethedisturbance.Thealteredaerodynamicforcegivesa

nose-downpitchingmoment,tendingtoreturntheaeroplanetoits

originaltrimmedcondition.

Example:thetailfinofadartoranarrow.

Figure2222longitudinalstabilityisprovidedbythe(ailfinsofadan

2,theCGandlongitudinalstability

Figure2.2-23AtforwardCG-greaterlongitudinalstability-longermomentarm.

ThefurtherforwardtheCGoftheaircraft,thegreaterthemoment

armforthetailplane,andthereforethegreatertheturningeffectof

thetailplaneliftforce.

AforwardCGleadstoincreasedlongitudinalstabilityandaft

movementoftheCGleadstoreducedlongitudinalstability.

Themorestabletheairplane,thegreaterthecontrolforcethatyou

mustexerttocontrolormovetheairplaneinmanoeuvers,whichcan

becometiring.

Thetailplaneprovidesstaticlongitudinalstability.

3,designconsideration

Tailplanedesignfeaturesalsocontributegreatlytolongitudinal

stability-tailplanearea,distancefromthecentreofgravity,aspect

ratio,angleofincidenceandlongitudinaldihedralareconsideredby

thedesigner.

Athighangleofattackthemainplanemayshieldthetailplaneor

causetheairflowoverittobeturbulent.Thiswilldecrease

longitudinalstability.

5.2.3Directionalstability

Directionalstabilityofanaeroplaneisitsnaturalorinbuiltability

torecoverfromadisturbanceinyawingplanewithoutanycontrol

inputbythepilot

Iftheaircraftisdisturbedfromitsstraightpathbythenoseortail

beingpushedtooneside(i.e.yaw).

Theverticalfin(ortailorverticalstabilizer)issimplya

symmetricalaerofoil.Asitisnowexperiencinganangleofattack,it

willgenerateasidewaysaerodynamicforcewhichtendstotakethe

finbacktoitsoriginalposition.

Uninvitedyaw

Figure2.2*24Directionalstabilityfollowingaskid

Thepowerfulmoment(turningeffect)oftheverticalfin,duetoits

largeareaandthelengthofitsmomentarmbetweenitandcentreof

gravity,iswhatrestoresthenosetoitsoriginalposition.

ThegreaterthefinareaandkeelsurfaceareabehindtheCG,and

thegreaterthemomentarm,thegreaterthedirectionalstabilityof

theaeroplane.

Thefinprovidesdirectionalstaticstability.

Astheyawcausesrollingmomentsothatbehavioroftheaircraft

withyawandsideslipinvolvesbothitsdirectionalstabilityandits

lateralstability.

5.2.4Lateralstability

Lateralstabilityisthenaturalorinbuiltabilityoftheaeroplaneto

recoverfromadisturbanceinthelateralplane,i.e.rollingaboutthe

longitudinalaxiswithoutanycontrolinputbythepilot.

Adisturbanceinrollwillcauseonewingtodropandtheotherto

rise.Whentheaeroplaneisbanked,theliftvectorisinclinedand

producesasideslipintotheturn.

Asaresultofthissideslip,theaeroplaneissubjectedtoa

sidewayscomponentofrelativeairflow.Thisgeneratesforcesthat

producesarollingmomenttorestoretheaeroplanetoitsoriginal

wings-levelposition.

1,wingdihedral

Figure2.2-27

Positivedihedral

correctsuninvitedbank.

Eachwingisinclinedupwardsfromthefuselagetothewingtip,

andaddstothelateralstabilitycharacteristicsoftheaeroplane.

Positivewingdihedralincreaseslateralstability.

Astheaircraftsideslips,thelowerwing,duetoitsdihedral,will

meettheupcomingrelativeairflowatagreaterangleofattackand

willproduceincreasedlift.

Theupperwingwillmeettherelativeairflowatalowerangleof

attackandwillthereforeproducelesslift.Itmaybeshielded

somewhatbythefuselage,causinganevenlowerlifttobe

generated.

Therollingmomentsoproducedwilltendtoreturntheaircraftto

itsoriginalwings-levelposition.

Figure2.2-28

Anhedralonahigh-mountedsweptwing.

Negativedihedral,oranhedralhasadestabilizingeffect.Insome

aircraftwithahigh-mountedsweepwing,anhedralisusedto

compensateforexcessivelateralstability.

2,wingsweepback

Thewingcanaddtolateralstabilityifithassweepback.Asthe

aircraftsideslipsfollowingadisturbanceinroll,thelower

sweepbackwinggeneratesmoreliftthantheupperwing.Thisis

becauseinthesideslipthelowerwingpresentsmoreofitsspanto

theairflowandhighervelocitythantheupperwingandthereforethe

lowerwinggeneratesmoreliftandtendstorestoretheaeroplanetoa

wing-levelposition.

3,highkeelsurfacesandlowCG

Figure1-31(RighUFinandrudder

Figure1-40KeelsurfaceareachangeswithCGposition.

Inthesideslipthatfollowsadisturbanceinroll,ahighsideways

draglinecausedbyhighkeelsurfaces(highfin,aT-tailhighonthe

fin,highwings,etc.)andalowCGwillgivearestoringmoment

tendingtoraisethelowerwingandreturntheaircrafttothe

originalwings-levelposition.

Figure2.2-30

HighkeelsurfacesandalowCGcorrectuninvitedbank.

4,high-wingaroplane

Ifagustcausesawingtodrop,theliftforceistilted.Theresultant

forceswillcausetheaircrafttosideslip.Theairflowstrikingthe

upperkeelsurfaceswilltendtoreturntheaircrafttothewings-level

condition.

Ahigh-wingaroplaneincreaseslateralstability,ithaslessdihedral

comparedtoamid-or-lowwingdesign.

Figure2.2-31

Pendulumstabilitytends

5,lateralanddirectionalstabilitytogether

1)rollfollowedbyyaw滚转引起偏航

Forlateralstability,itisessentialtohavethesideslipthatthe

disturbanceinrollcauses.

Figure2.2-32Rollcausessideslip,whichcausesyaw.

Thesideslipexertsaforceonthesideorkeelsurfacesofthe

aircraft,which,iftheaircraftisdirectionallystable,willcauseitto

yawitsnoseintotherelativeairflow.Therollhascausedayawin

thedirectionofthesideslipandtheaeroplanewillturnfurtheroffits

originalheadinginthedirectionofthelowerwing.

Thelateralstabilitycharacteristicsoftheaeroplane,suchas

dihedral,causethelowerwingtoproduceincreasedliftandtoreturn

theaircrafttothewings-levelposition.

Therearetwoeffectsinconflicthere:

Thedirectionallystablecharacteristics(largefin)wanttosteepen

theturnanddropthenosefurther.

Thelaterallystablecharacteristics(dihedral)wanttolevelthe

wing.

spiralmode螺旋模态，Dutchroll荷兰滚

right矫正，best极力，wallow摇摆

Ifthefirsteffectwinsout,i.e.strongdirectionalstabilityandweak

lateralstability(largefinandnodihedral),thentheaircraftwilltend

tobankfurtherintothesideslip,towardsthelowerwingwithnose

continuingtodrop,untiltheaeroplaneisinaspiraldive.Thisis

calledspiralinstability,orthespiralmode.

Ifthelateralstability(dihedral)isstronger,theaircraftwillright

itselftowings-level,andifthedirectionalstabilityisweak(small

fin)theaircraftmayshownotendencytoturninthedirectionof

sideslip,andcausingthewallowingeffect,Dutchroll,whichisbest

avoided.

2)yawfollowedbyroll偏航引起滚转

Figure2.233Yawcausesrollandsideslipandfurtherroll

Iftheaircraftisdisplacedinyaw,itiscancausesideslip.This

sideslipwillcausethelateralstabilitycharacteristicsoftheaircraft's

wing,suchasdihedral,sweepbackorhigh-wing.Thiscausesa

rollingmomentthatwilltendtoraisetheforwardwing,resultingin

theaircraftrollingtowardsthetrailingwingandawayfromthe

sideslip.

Theaircraft'sinherentdirectionalstability(fromthefin)willtend

toweathercockoryawtheaircraftinthedirectionofsideslip.

3)stabilitycharacteristicsandaeroplanecontrol

Ifthedirectionalstabilityispoor(smallfin)andthelateral

stabilityisgood(dihedral)itcancauseDutchroll(rolling/yawing

oscillation).Oftentheaircraftisfittedwithayawand/orroll

damper(asmallcontrolsurfacedrivenbyarategyro)tostopthe

oscillation.Itisuncomfortableforthepilotandpassengers.

Ifthedirectionalstabilityisdominant(largefin)andthelateral

stabilitynotsostrong,itcancausespiralinstabilityorspiralmode.

rategyro阻尼陀螺，dominant占优势，占主导地位

6,Stabilityontheground

tipover翻倒，taxing滑行，groundloop地转

skid空转，brake刹车，wheel车轮

runway跑道

Thecentreofgravity(CG)mustliesomewhereinthearea

betweenthewheelsatalltimesontheground,otherwisethe

Centreof

gravity

Figure2.2-34TheCGmustremainwiihintheareaboundedbythewheels.

aeroplnewilltipover-forwardsorbackwards.

Track

ApplyleftrudderWeathercocking

tocounleraclthistendency

crosswindand

maintainthedesired

trackalongtherunway.

Wind

Rudderdeflected

u，/tocounteractyaw

Figure2.2-35Weathercocking.

5.3Control

Thecontrolsurfacesarethemeansbywhichthepilotovercome

thestaticstabilityoftheaircraftandcausesachangeinflightpathor

achangeintrimmedconditions.

Figure2.2-36

Theprimarycontrolsurfaces-elevator,aileronsandrudder.

Usuallytherearethreesetsofprimarycontrolsystemandthree

setsofcontrolsurfaces:

•theelevatorforlongitudinalcontrolandbalanceinpitch,operated

byforeandaftmovementofthecontrolwheelorcolumn;

•theaileronsforlateralcontrolandbalanceinroll,operatedby

rotationofthecontrolwheelorsidewaysmovementofthecontrol

column;

•therudderfordirectionalcontrolandbalanceinyaw,operatedby

therudderpedals.

Ideallyeachsetofcontrolsurfacesshouldproduceamoment

aboutonlyoneaxisbut,inpractice,momentsaboutotheraxesare

oftenproducedaswell,e.g.ailerondeflectiontostartarollmayalso

causeadverseyaw.

Thedeflectionofthecontrolsurfaceschangestheairflowandthe

pressuredistributionoverthewholeaerofoilandnotjustoverthe

controlsurfaceitself.

Theeffectistochangetheliftproducedbythetotalaerofoil­

controlsurfacecombination.

Anaeroplanewithtoomuchstabilitydesignedintoithaslimited

controllability.Thedesignermustachieveareasonablebalance

betweenstabilityandcontrollability.

Forinstance,apassengeraircraftwouldrequiremorestability,

whereasafighterwouldbenefitfromgreatercontrollabilityand

manoeuvrability.

5.3.1Pitchcontrol

1,Elevator

Upwardaerodynamic

,ControlcolumnControlcolumnforce/—j

丁backUpforward/T

elevator

Nose

Nose%一_~^75^down

Down

elevator

Downward

a029A

Figure2.2-37Theelevatoristheprimarypitchingcontrol

Theprimarycontrolofangleofattackistheelevator.

Thepilotmovestheelevatorbyfore-and-aftmovementofthe

controlcolumn.

Whenthecontrolcolumnismovedforward,theelevatorsmove

downwards,changingtheoverallshapeofthetailplane-elevator

aerofoilsectionsothatitprovidesanalteredaerodynamicforce.

TheeffectistocreateapitchingmomentabouttheCGofthe

aircraftthatmovesthenosedown.

Whenthecontrolcolumnispulledback,theelevatormovesup

andanalteredforceisproducedbytailplane-elevatoraerofoil,

causingthenoseoftheaircrafttopitchup.

Thestrengthofthetailmomentdependsontheforceitproduces

andthelengthofthearmbetweenitandtheCG.Theforcegenerated

bythetailplane-elevatorcombinationdependsontheirrelativesize

andshape,thetailplanebasicallycontributingtostabilityandthe

elevatortocontrol.

Thelargertherelativesizeoftheelevator,themorethecontrol.

Toretainsatisfactoryhandlingcharacteristicsandelevator

effectivenessthroughoutthedesiredspeedrange,thepositionofthe

CGmustbekeptwithintheprescribedrange.

TheforwardallowablelimitoftheCGisdeterminedbythe

amountofpitchcontrolavailablefromtheelevator.

TheaftlimitoftheCGisdeterminedbytherequirementof

adequatelongitudinalstability.

Steadyflightatalowspeedandahighangleofattackwillrequire

significantup-elevator,andbackwardpressureonthecontrol

column,tokeepthenoseup.

Steadyelevatordeflectionatdifferentspeeds.、

Atahighcruisespeedtherewillneedtobeasteadydown

deflectionoftheelevatortokeepthenosedownandmaintainalow

angleofattack,henceasteadyforwardpressureonthecontrol

column.

2,Thestabilatororall-flyingtail

Figure2.2-40Separatetailplaneplusmovingelevator(left),andstabilatororall-flymgtail(right).

Somedesignerschoosetocombinethetailplaneandelevatorinto

theonesurfaceandhavethewholetail-planemovable-knownasthe

allmovingtail,theflyingtailortheslabtail.

Whenthecontrolcolumnismovedtheentire'slab'moves.

5.3.2Rollcontrol

1,Ailerons

Theprimarycontrolinrollistheailerons.Theaileronsare

usuallypositionedontheoutboardtrailingedgeofthemainplanes.

Theaileronsactinopposingsenses,onegoesupastheothergoes

down,sothattheliftgeneratedbyonewingincreasesandthelift

generatedbytheotherwingdecreases.

Aresultantrollingmomentisexertedontheaeroplane.

Themagnitudeofthisrollingmomentdependsonthemoment

armandthemagnitudeofthedifferingliftforces.

•Thedowngoingaileronisontheupgoingwing.

•Theupgoingaileronisonthedowngoingwing.

2,Adverseaileronyaw

Deflectinganailerondowncausesaneffectiveincreaseincamber

ofthatwingandanincreaseintheeffectiveangleofattack.Thelift

fromthatwingincreases,butunfortunatelysodoesthedrag.Asthe

otheraileronrises,theeffectivecamberofthatwingisdecreasedand

itsangleofattackisless,thereforeliftfromthatwingdecreases,as

doesthedrag.

Rollright

Sameamountof

ailerondeflection

Rearview

Figure2.2-42Downwardaileronhasincreaseddrag-adverseyaw.

Thedifferingliftforcecausestheaircrafttobankoneway,but

thedifferentialailerondragcausesittoyawtheotherway.

/'一隔I

'.^一jIncreaseddeflection

ofupgoingaileron

Differentialailerons

Figure2.2-43Differentialaileronsequaliseailerondrag,reducingadverseyaw.

Adverseaileronyawcanbereducedbygooddesignincorporating

differentialailerons,Friseailerons,orcouplingtheruddertothe

ailerons.

Lift

Figure2.2-44Frise-typeaileronsequaliseailerondragandreduceadverseyaw

・Differentialailerons（差动）aredesignedtominimizeadverse

aileronyawbyincreasingthedragonthedowngoingwingonthe

insideoftheturn.Thisisachievedbydeflectingtheupwardaileron

throughagreateranglethanthedownwardaileron.

・Friseaileronsincreasethedragofthedescendingwingonthe

insideoftheturn.Astheailerongoesup,itsnoseprotrudesintothe

airstreambeneaththewingcausingincreaseddragonthedowngoing

wing.

Ontheotherway,thewingisrising,thenoseofthedowngoing

ailerondoesnotprotrudeintotheairstream,socausenoextradrag.

Frise-typeaileronsmayalsobedesignedtooperatedifferentially,to

incorporatethebenefitofdifferentialailerons.

•Coupledaileronsandruddercausetheruddertomove

automaticallyandyawtheaeroplaneintobank,opposingtheadverse

yawfromtheailerons.

Theprimaryeffectofrudderistoyawtheaeroplane,andthe

secondaryeffectistorollit.Theprimaryeffectofaileronsistoroll

theaeroplane,andthesecondaryeffectistoyawit.

3,Rollisfollowedbyyaw滚转引起偏航

Thesecondaryeffectofaileronsistocauseyaw.

Whentheaeroplaneisbankedusingtheailerons,theaeroplane

willslip.Asaresultofthesideslip,theairflowwillstrikethesideof

theaeroplaneandthelargekeelsurface(rearfuselageandfin),

whicharemainlybehindtheCG,causethenoseoftheaeroplaneto

yawinthedirectionofbank.

Figure2.2-46Rollisfollowedbyyaw.

5.3.3Yawcontrol

1,Rudder

Figure2.2-55Leftrudderpressure-noseyawsleft.

Theprimarycontrolintheyawingistherudder.Therudderis

hingedtother