z!-
a NATIONALADVISORYCOMMITTEEFORAERONAUTICS
“TECHNICAL NOTE4058
CALCULATEDEFFECTOFSOMEAIRPLANEHANDLINGTECHNIQUES
ONTHEGROUND-RUNDIS’T4iNCEIN LANDING
ONSLIPPERYRUNWAYS
ByJohnA. zdOVCik
LmgleyAeronauticalLaboratoryLangleyField, Va.
WashingtonJuly1957
https://ntrs.nasa.gov/search.jsp?R=19930084913 2018-05-30T12:31:18+00:00Z
TECfILIBRARYKAFB,NM
K lilllllllllfllllllllilllNATIONALAJXCSORYCWITTEE FORAERONAUTICS Uffbb7:7
TECHNICALNOTEk@
cAL~ Em?EcTal?S(MEAIRPLmEHANDLINGTECENIQW
ON THEGROUND-RUNDISTANCEINLANDING
ON SLIPPERYRUNWAYS
~ ~dm A. =lOVCik
SUMMARY
Somecalculationsweremadeon thebasisof simplifyingassumptions_&mdeterminetheeffeeton theground-rundistanceofmaintaininga nose-highattitudeinsteadofa three-pointattitudein landingsof severaltypesof jetairplaneson slipperyrunways.Theairplanesconsideredwerea swept-wingtransportandunswept-,swept-,snddelta-wingfighters.Theeffectof suchfactorsas speed,brakingeffectiveness,andresidualthruston thedifferenceinground-rundistancewiththetwohandlingtechniquesisbrieflyconsidered.Somecomputationswerealsomadetoindicatetheeffectof instantaneousflapretractionon
INTRODUCTION
Intheproblemofsz’restingairplanes
theground-rundistance.
landingon slipperyrunways,someqwstionhasbeenraisedastowhethera shortergroundrunmaybeeffectedby nosinganairpl&medowntothethree-pointattitudeimmedi-atelyaftertouchdownandapplyingthebrakesthanbymaintaininga nose-highattitudeangleforscmedistancedowntherunway,stisequentlyloweringthenosewheeltotherunway,[email protected] scmefighterairplanesls.ndingonrunwaysduring,or imw=di-atelysd%er,a heavyrainhaveben reportedtomakeuseofthenose-high-attitudetechnique.Thistechniqpeisalsoreportedtohavebeenusedby sanepilotsoftransportsondryrunways.
Thechiefpurposeofthisanalysisisto indicateby simplifiedcal-culationthepossibledifferencesinground-rundistancesforseveraltypesof jetairplanesobtainedby usingthetwopretious~describedtechniquesinlandingon slipperyrumways.Theeffectof suchfactors
. as speed,brakingeffectiveness,andidlingthrustonthedifferenceinground-rundistancewiththetwohandlingtechniquesisalsobrieflyconsidered.
*
2 NACATN 4058
Becausethequstionisoftenraisedastotheeffectivenessofretractingflapsduringa groundrun,smneresultsarepresentedfortheeffectof instantaneousflapretmctionatwound contactontheground-rundistance.
Gromd-rundistsncesarepresentedforrunwaysurfaceconditionshavingmsximumavailabletire-to-groundfrictioncoefficientsbelow0.3.Frictioncoefficientsinthiscientstypicaloflandingsonrunways,andon icysurfaces.
rangewouldinclude,forexsmple,coeffi-wetrunwaysathighspeeds,on snuw-covered
SYMBOLS
airplanedragcoefficient
airplaneliftcoefficient
incrementindragcoefficientduetoflap
incrementinliftcoefficientduetoflap
Iaccelerationdueto gravity,32.2ft sec2
wingincidencewithrespecttofuselsgereferenceline,deg
airplanelift,lb
dynamicpressure,g, lb/sqft
airplanewingarea,sqft
ground-rundistance,ft
residualor itiingthrust,lb
the, sec
airplanespeed,ft/sec
airplaneweight,lb
angleofattackoffuselagereferenceline,deg
.
.
NACATNh58 3
Cfm angleofattackmaintainedaftertouchdowninlanding,deg
P sea-leveldensity,slugs/cuft
v frictioncoefficient
pa maxianmavailabletire-to-groundfrictioncoefficient
~b airplanebrakingcoefficient
h rolling-frictioncoefficient,0.02
Subscripts:
13 atthree-pointattitude
max maximum
n at timewhenairplaneisnoseddownfrm a high-attitudeangleduringgroundrunto a three-pointattitude
s at stall;alsoattimewhen W = SqC~,w
t atmomentoftouchdown
METHODOFANALYSIS
Airplanes
Forthepurposeof evaluatingtheeffectof a nose-highattitudeangleon theground-rundistancenecessaryinairplanelandings,severaljetairplanesconsideredtypicalofmodernaircrafthavebeenselectedforstudy..Theairplsneschosenincludea sweptback-wingjettrans-port,threesweptback-wingfighters(identifiedasfightersA, B, andC),sm unswept-wingfighter,sada delta-wingfighte+.Someof thephysicalcharacteristicsof theseairplanesaregivenin tableI. me aerodynamiccharacteristicsnecessaryforthecalculationswereobtainedfromavail-ablewind-tunnelandflightdata,orwereestimatedwhensuchdatawerenotavailable,andareshowninfigure1. Correctionsforgroundeffectwereestimatedbymethodof reference1.
Theeffectof flapretractionon landingground-rundistancewascalculatedforallairplanesexceptthetaillessdelta-wingfighter.Theincrementsinliftad dragcoefficientscontributedby theflapsaregivenin tableII.
,
4 NACATN 4058
EffectofAirplaneAttitude
Landingdistancefor Vt = 1.05V~.- ThetypeofvariationofattackwithspeedassumedinthecmnputationoftheJandingrundistanceisillustratedinfigure2 fora toucMownspeed~ pe?.’centabovethestallingspeedVs,whichcorrespondsto acoefficientof 0.91~,=. Thecurve~abeled“a”corresponds
*
of angle●
ground-Vt of —lift —toa“
landinginwhichthepilotmaintainstheangleofattackcorrespondingto ~ percentabovestallingspeeduntila speedVn isreached.Theangleofattackisthenasswedtobe decreasedinstantlyat speedVnto thethree-pointattitudeandkeptatthisattitudefortherestofthegroundrun. Thecurvelabeled“b”correspondsto a landinginwhichthepilotnosestheairplanedowntothethree-pointattitudeattheinstantof contact.Inthehandlingtechniqpeindicatedby curvea,thebrakesareappliedonlytitertheairplaneisnoseddowntothethree-pointattitude.Forthetechniqueindicatedby curveb thebrakesareassumedtobe appliedimmediatelyontouchdown.Duringbraking,theentireverticalload(W- L) isass&edtobe takenonthemainwheels.Forthehandlingtechniqyeindicatedby curveb, thisassump-tionwi31smounttotheuseof justenoughelevatortokeeptheloadoffthenosewheel.At speedsbelow Vn theairplanewillbeatthethree-pointattitudeforbothhandlingtechniqmsand,consequently,thatpartoftheground-rundistancebetweenspeedsVn and O isthesameforbothtechniques.Fortheunswept-andswept-wingairplanesconsideredherein,theflapssmeassumedto remaindownthroughoutthegroundrun.
?
Thelandingground-rundistanceintheabsenceofwindiscanputedonthebasisoftheeqmtion
—
or,inanalternateform,i
1 dq CDq.— =-— .gpds CL,tqt (
~1-
-L)+T
cLq ) T
cL,tqt‘F
where,attouchdown,itisassumedthat
w = cL,-@&a
(1)
.
*
.
#
.
.
Intheintegrationofequation(l),thefrictioncoefficientv istakenasa constantrolling-frictioncoefficient~ duringthenose-high-attitudepartofthegroundrunsmdas a constantbrakingcoeffi-cient ~b duringthethree-point-attitudepartof the run. Sincethevalueof & issmall(takenhereas0.02)(refs.2 and3), itsvaria-tionwithspeedwouldhavea negligibleeffectonthelandingground-rundist=ce. Thebrakingcoefficientpb dependsonthepilot’stechniqueinapplyingthebrakes,ontherangeoftire-skiddingvelocitiesoverwhichantiskiddevicesoperate(iftheairplaneissoeqpipped),onthebrsk.etorqpelimitation(whichisa functionof speedandbraketemper-ature),andontherunwaysurfacecondition(whichdeterminesthemaxi-mumavailabletire-to-groundfrictioncoefficient~). Informationonthevsriationof pa withspeedisverymeager.On slipperysurfaces,suchasthoserepresentedby valuesof ~ between0.05and0.32 ~aprobablydoesnotvarymuchwithspeed.Inviewofthevarying”natureoftheseveral.factorsthateffectPb,thevalueof ~ cannotbeexpressedexplicitlyasa functionof speedand,hence,isassumedtobe constantfora givenrunwayconditionintheintegrationofequa-tion(l). Onthebasisoftion(1)@elds theground
(
theseassumptions,theintegrationof-equ-distances,asfollows:
1s=~ 1m cD,t
lo%‘D.t T
Vr-—CL,t
1CL,g CD,g
~b~- CL,tY
(. )%,t%Tkc-kc- -—~
cL,t % +n—-—cL,t w
(2)
Thefirsttermontheright-handsideofequation(2)representsthedistanceduringthatpartofthegroundrunwiththenose-highattitudeandthesecondterm,thedistanceduringthatpartwiththeairplaneatthethree-pointattitude.Solutionofeqution(2)forvariousvalues
of %— < 1.0 yieldstheground-rundistanceforcurvea offigure2;%
6. NACATNko58
qnwhereasthesolutionwith — = 1.0 givesthedistanceforcurvebqt
sincethefirsttermontheright-handsideofequation(2)becomeszero.
Eqyation(2)isvaliduptothelowestvalueof ~ thatpermitsdevelopmentofmaximumbrakingtorqueforcontinuousoperation.Forthepresent-daytransportsthemsximumbrakiqgtorqueforcontinuousoperationappearstobe intherangethatwouldprovidea deceleratingforceduetobrakingof 0.234to 0.3W. Ifthehigherofthesetwovaluesisassumed,as itisherein,thelowestvalueof ~ atwhichmaximwubrskingtorqueforcontinuousoperationisdevelopedwillbe,foreqle, 0.3for Vb =%, O.lfor Pb = 0.’75~,and0.6for~b = 0.50va. T@ calculationsarethereforemadeforvaluesof ~ Upto thatatwhichtbemaximumbrakingtorquewillbe developed.If stop-pingdistmcesathighervaluesof Va aredesired,ttifriction~~V(W- L) ineqwa.tion(1)willhavetobe replacedby O.~ atthetimeduringtherunwhenmaximumbrskingtorqueisdeveloped.
Theground-rundistemceforattitudeangles~ otherthanthat
.
m
correspondingto a speed5 percentabovestallingspeediscalculated.—
fortheswept-wingfightersB andC andthedelta-wingfightertouchingdownat 5 percentabovestaUingspeed.Theassumedvariationofangleofattackwithspeedfortheseairplanesisillustratedinfigures3 ?to 3.
—
Landingdistancefor Vt = l.30vs.-Forcomparisonwiththedistanceata touchdownspeedof5 percentabovestallingspeed,thegroun”d-rundistanceforthedelta-wingfighteriscalculatedfora touchdownspeedof30percentabovestallingspeedwithseveralattitudeangles~.Theassumedvariationofangleofattackwithspeedduringthegroundrunforvariousattitudeanglesis HJ.u,stratedinfigure6. Forattitudeangles”greaterthantheangleofattackcorrespondingtoa speedN per-centabovestallingspeed,thepilotiSass~d to increa=theangleofattackasthespeeddecreases)in sucha waYt~t t~ ~ft oft~airplaneiseq~ totheweightuntilthedesiredground-attitudeangleisattained.ThegroundrunisthencontinuedatthisangledowntospeedVn atwhichtheangleofattackisassumedto decreaseinstantlytothethree-pointattitudeandthebrakesareapplied.Theground-mdistanceisgivenby theeqmtion
NACATN k058 7
.
.
[
()l% - MCD,S % T-—— -.
q~ 1 CL,S % ‘+G CD,s 10% CD,S T
&-- —- —CL,S CL,S w
1-
1
CL,g CD,g‘bCL,~
—-—CL,s
!-+loge
( CL,g cD,g %
)b-;- ~b~-—— CL,S %> 1
.
(3)
Thefirsttermontheright-handsideofequation(3)isthedistanceduringthepartoftherunwhen L =W. Thesecondtez?nisthedistsmceforthatpartoftherunwiththeconstantnose-highsingleofattack.Thelasttermisthedistanceforthebrakingpartoftherunwiththeairplaneatthethree-pointattitude.Forattitudesingleslessthanthatcorrespondingtoa speedof~ percentabovestallingspeed,theangleofattackisass-d to decreaseinstantlyat contacttothedesiredattitudeangle.Thegroundrunisthencontinuedatthisatti-tudedownto speedVn atwhichthemgle ofattackisassumedtodecreaseinstantlytothethree-pointattitudeandthebrakesareapplied.Theground-rundistsmceisgivenby equation(2)forthiscase.
EffectofFlapRetraction
Theground-rundistancewithflapsretractedis calculatedforall “airplanesexceptthetaillessdelta-wingairplaneby usingequation(2)~ndassum$ngthattheairplaneisnoseddownto a three-pointattitude
k=‘)1 0 withtheflapsretractedattheinstantofgroundcontact.
me entirevertical.loadisassumedtobe carriedonthemainwbeel.s.
.
u
8 NACA~ h.058
RESULTS .
EffectofAirplaneAttitude.
Landingdistanceat Vt = l.05Vs.- Thelandingground-rundistanceforseveraltypesof Jetairplanestouchingdownat 5 percentabovestallingspeedisshowninfigure7 forvariousconditionsoftherun.way,as indicatedbythemsximumavailabletire-to-groundfrictioncoef-
ficient
ficient
friction
Vn2 ~l% andfor=ious =Iues of
()~ ‘~” Thebrakingcoef-
~b isassmnedeqyaltothemsxinnmavailabletire-to-ground
V2coefficient~a. H~ CUI’VeSlaleled ~~ = 1.0 represent
the ground-run distancescurve b infig.2) where
thethree-pointattitude
\’t/
forthehandlhgtechnique(indicatedbytheangleofattackisdecreasedimmediatelyto
Vn 2attouchdown.Curveslabeled
()86=0 .,0.,
~and0.4 representground-rundistancesforthehandlingte-chnique(indicatedby curvea infig.2)wheretheattitudeanglecorresponding “to thatfor5 percentabovestallingspeedwasmaintaineduntilthe-C pressure had decreasedtovaluesof80,60,and4-0percentofthedynemicpressureattouchdown,respectively. w
—
Accordingtofigures7(a),7(b),and7(e)thereisnoadvantageinmaintaininga nose-high-attitudeangleaftertouchdownfortheunswept-wingfighter,theswept-wingfighterA, ortheswept-wingtransport.Infact,forthesethreeairplanestheground-rundistanceincreasesconsiderablyfortire-to-groundfrictioncoefficientsgreaterthan0.05,whichrepresentsa veryslippe~surface.Fortheswept-wingfightersBandC (figs.7(c)and7(d)),somesmallreductioninground-rundistsmcecanbe obtainedforvaluesof & lessthanabout0.10.Atvaluesof ~greaterthan0.10,theincreaseinground-rundistanceisappreciable. ——
Theeffectontheground-rundistanceoflimitingtheattitudeangleinlandingisillustratedinfigures8 to 10. Ifthemadmumattitudeanglewerelimited,forexsmple,by tail-pipeclearance,to 10°insteadof 16°forswept-wingfighterB,andto 5°insteadof9°forswept-wingfighterC,thenose-high-attitudetechniquewouldresultinan increaseinground-rundistanceevenatvaluesof’~ downto approximately0.05.Forthedelta-wingfighteroperatingatanattitudeagglecorresponding -to 5 percentabovestallingspeed(about_20°),thereductioninground-rundistance(fig.10(a))isobtainedatvalues of Pa belowapproxi-mately0.2withratherlargereductionsobtainableonveryslippery m
K
.
.
NACATN4058 9
(-f== Pa ‘ 0.05).Foranattitudeangleof15°,onlysmallreduc-tionsindistanceareobtainedandonlyatvaluesof ~ lessthanapproxhately0.08(fig.10). Foran attitudesinglelimitedto a maxi-mumof100,noreductionisobtainedwiththenose-high-attitudetech-niquedowntoaval.ueof ~ of0.05.
t
Landingdistanceat Vt = 1.30Vs.-Theground-rundistanceforthedelta-wingfighterlandingata speedof ~ percentabovestallingspeedis showninfigureU forseveralattitudeangles.Thecurveslabeled
()
Vn 2
~ = 0.26,0.39,and0.52 correspondto curvesoffigure8 labeled
Vn2() 0.k, 0.6, and0.8,respectively,inasmuchasthecorresponding~=curveshavethessmevalue of Vn. A comparisonoffigures10and11indicatesthatthevalueof ~ belowwhicha reductioninground-rundistanceisobtainedwiththenose-high-attitudetechniqmisaboutthesue forthetwotouchdownspeeds.Thereductionor increaseindis-tancebothinpercentandinabsolutemagnitude,however,isappreciably
. greaterforthehighertouchdownspeed.
Landingdistancewithreducedbrakeeffactiveness.- Theground-rundistanceforthedelta-wingfighterwithreducedbrakeeffactivenessisshowninfigure12fora touchdownspeedof5 percentabovestallingspeed.Theangleofattackduringthenose-highattitudeofthegroundrunwastakenas 20°. CurvesareshownforbrakingcoefficientsUbof100,~, and50percentofthemaximm.navailabletire-to-groundfric-tioncoefficient~. A brakingcoefficientconsiderablylessthanthemaximumavailabletire-to-groundfrictioncoefficientmaybe obtainedasa resultof cyclingofthemtiskiddeviceovertoogreata rangeofskiddingvelocities,of inefficientbrakingby thepilot,orof insuf-fi.cientbraketorque.As aaexampleoftheefficiencyof oneinstaUa-tionofantiskiddevices,somerecentNACAtestsofan airplsneequippedwithonetypeofantiskiddeviceindicatedan averagebrakingcoeffi-cient ~b ofabout O.7pa whilethedevicecycledovera rangeoftire-skiddingvelocitiesfranO to about 70percentoftheunbraked-wheelrollingvelocity.Theresultsinfigure12 showthat,asthebrakingcoefficientVb isreduced,thenose-high-attitudetechniquegivesgreaterreductionsinground-rundistanceontheveryslipperysurfaces.Thevalueof pa belowwhichthereductionsareobtained.is increased
./
by thefactor~ Vb. Forexsmple,forthedelta-wingfighterwith
% = 20°,reductionsareobtainedat ~ *1OW about0.2for Ub = &. andat ~ belowabout0.4for Pb = O.51Ja.
10
Landingdistancewithresidualthrust.-(idling)thrustT onthegroundrunofthecatedinfigure13,whichshowsa comparison
NACATN4078
Theeffectoftheresidualdelta-wingfighterisindi-oftheground-rundistance
for T/W= 6 and0~025.Fora ratioofmaximumthrusttoweightof0.5,thevalueof T/W= 0.025 correspondstoa [email protected] percentofmaximumthrust.Withthisresidualthrusttheground-rundistance
(onveryslipperysurfaces~a = 0.05)is,of course,excessivefortheconditionwhentheairplaneisnoseddowntothethree-pointattitudehmnediatelyandbrakesareappliedVn( = Vt). Althoughthereductions
!.. indistanceobtainedbymaintaininga nose-highattitudeareratherlsrgeforthissurfacecondition,theground-rundistanceis stillsogreatasperhapstorequireotherarrestingmeans. (Itshouldbe notedthatanantiskiddeticewhichwouldgivea brakingcoefficientequaltothemaximumavailabletire-to-groundcoefficientisassumedtoW operatingduringbraking,a conditionthatdoesnotappeartobe realizedinpractice.)Thereductioninground-rundistanceobtainedbymaintaininga nose-highattitudeisobtainedatvaluesof ~ lessthanabout0.2fora residualthrustofbothO and 0.025W,butthereductionsaregreaterwitha residualthrustof 0.025W..Theeffectoftheresidualthrustatthelowvaluesof Wa isapproximatelyequivalentto a reduc-tioninthevalueof Va by thevalueof,T/W.
.
—
Energyinputtobrakes.-Theuseofthenose-high-attitudetechniqueresultsina reductionintheenergyinputtothebrakesandhenceinareductionofbrakeandtirewear. Thereductionintheenergyabsorbed aby thebrakes,expressedasa fractionoftheener~ absor~edby thebrakes
Vn
(())
22when — = 1.0,isgivenapproximatelyby theexpression1 -Vt Vt “Fortheconditionsinwhichthenose-highattituderesultsina decreaseintheground-rundistance,theadvantagesofthistechniqpearetwofold.Forconditionsinwhichthenose-highattituderesultsinan increaseinground-rundistance,thereductioninenergyinputtothebrakeswindependontheincreaseinground-rundistancethatcanbe tolerated.Whentheairplanehasinsufficientbrakecapacityto absorbthekineticenergyoftheiirplaneincourse,be usedifmeansofarresting
Theeffectof
landing,thenose-~gh-attitudetechniqpemust,of ‘-sufficientrunwaylengthisavailable;otherwise,othertheairplanemustbe provided: ..
EffectofFlapRetraction
instantaneousflapretractionontheground-rundis-tanceduringbrakingis showninfigure14fora touchd&nspeedof5percentabovesta~ingspeedwithzeroresidualthrustand ~b = ~.Fortheswept-wingtransport,reductionsinground-rundistanceare
NACATN !L058 .32
. obtainedthroughinstantaneousflapretractionatvaluesof & downto 0.05(fig.lk.(e)).Thereductionsatthehighervaluesof pa are
. appreciable.Withgraduslflapretractionthereductionwouldbe smallerandwoulddependontheflapretractiontime. FortheotherairplanesinstantaneousflapretractionproducesMttl.eor noreductioninground.rundistanceabovevaluesof ~ ofabout0.2(or0.4for Pb = o.5~a)anda relativelylargeincreasebelowthesevalues.At thehighertouch-downspeeds,20percentabovestalJingspeedfortheswept-wingtransportand~ percentfortheunswept-wingsadswept-wingfighters(fig.1~),thevalueof ~ abovewhichthereduction(orbelowwhichan increase)inground-rundistanceis obtainedisaboutthessmeas atthelowertouchdawnspeed,butthemagnitudeofthereduction(orincrease)isconsiderablygreater.Withresidualthrustof 0.02~ (fig.16),instantaneousflapretractionincreasestheground-rundi.stsmceappre-ciablyabovethatwithzeroresidualthrustatthelowvaluesof ~.At thehighervaluesof ~a theresidualthrustof O.O& hasa neg-ligibleeffectonthedecreaseinground-rundistanceobtainedwithflapretraction.
CONCLUDINGREMARKS
Calculationsofground-rundistanceforseversldifferenttypesofjetairplaneshavingbrakingcoefficientsequalto themaximumavailabletire-to-groundfrictioncoefficientindicatedthatnoreductioninground-rundistsmcecouldbe effectedhy maintaininga nose-highattitudeduringthegroundrunfora swept-wingtransport,anunswept-wingfighter,andonetypeof swept-wingfighter.Somesmallreductionsinground-rundistancewereindicatedfortwootherswept-wingfightersona veryslip-peryrumway(atvaluesofmaximumavatlabletire-to-groundfrictioncoef-ficientlessthanabout0.10).A nose-high-attitudeangleintheneigh-borhoodofthestallangleofattackduringa groundrunofa delta-wingfighterresultedinan appreciablereductioninlandingdistanceatval-uesofmaximumavailabletire-to-groundfrictioncoefficientlessthanabout0.2(orabout0.4forbrakingcoefficientseq~l to x percentofthemaximumavailabletire-to-groundfrictioncoefficient).If,however,thenose-high-attitudesinglewerelimitedby tail-pipeclearanceorbyotherfactorsto abouthalfthestaU angle,noreductioningroundrunwouldbe indicatedforthedelta-wingfighter.Retractingtheflapsattheinstantof groundcontactledto reductionsinground-rundistancefortheswept-wingtransportfortire-to-groundfrictioncoefficientsdowntoabout0.05.Fortheunswept-andswept-wingfighters,flapretractionresultedinanappreciableincreaseinground-rundistanceatmsxbnumavailabletire-to-groundfrictioncoefficientslessthanabout0.2
12 NACATN 4058
(orlessthanabout0.4forbrakingcoefficientseqpalto 50percentof -themaximumavailabletire-to-groundfrictioncoefficient).
.
LangleyAeronauticalLaboratory,PWi.tiOIIal Advisory COMMit%efOrAeronautics,
LsngleyField,Vs.,April22,19570
REFERENCES
1. ‘Tani,Itiro,Taima,MSUO, andSimidu,SOdi: ThelMfectof GroundontheAerodymunicCharacteristicsofa MonoplaneWing. Rep.No.156(vol.XEH, 2),Aero.Res.Inst.TokyoImperialUniv.,Sept.1937.
2.Wetmore,J.W.: TheRollinglRrictionofSeveralAirplaneWheelsandTiresandtheEffectofRollingFrictiononTake-Off.NACARep.NO. 583,1937.
3. Pike,E. C.: CoefficientsofFriction.Jour.R.A.S.,vol.53,MC. 1949,pp.1085-1094.
.
r
NACATN 4058
TAELEI.-AIRPLANEPHYSICALCHARACTERISTICS
w/s, A~pct Sweepbackofwing ~g, ~,Airplane lb/sqft ratio qpsrterchord,
deg deg deg
Unswept-wingfighter 54 0 0Swept-wingtransport 70 ;:: 3; 3 0Swept-wingfighterA 4.8 0 0Swept-wingfighterB G Z o 0Swept-wingfighterC 52 ::; 35 0 0Delta-wingfighter 28 2.0 52 0 0
I
‘TABLEII.- FLAPCHARACTERISTICSATANGLE
OFATTACKFORTHREE-POINTATTITUDE
7
Airplane ‘L,f ‘D,f
Unswept-wingfighter 0.78 0.132Swept-wingtrsnsport .87 .044Swept-wingfighterA .4Q .060Swept-wingfighterB .31 .084Swept-wingfighterC ●39 .098
211
1.6
CL 1.2
.8,
.4
-—- —--. —— —---.— —
—— -——— —-—
0 10
Figure
20a, deg
1.- AerOdymmic
u-t-au fidt=>fl- ~~.%@.-awfighterA, fI.wsd~n9WPHI’W fii@ter% f@s dmm-IL@ fWtir C, EI.6PdamDdta-ming [email protected],flaps&ma
CD
c~act.erlstlcstith groundeffect~l*d”
. . * .
●
a 1’1“
b——~- ]7V+
0 vFigure 2.- Assmnedvariationof angle
groundrun.
~m, deg
I !6
of,attackwithV* = l.o~s.
speedduringlanding
f
Tazchdom
c!
A
!f -1 ●91CL,=
10I
I .\lVn I/Vt0’-~-—
0 vFigure3.- Assumedvariationof angleof attackwith
qmund runforswept-wingfighterB. Vt =speedduringlanding1.o~vs●
16 NACATN 4058
a
am,deg9
V 5
‘“N’ ‘ .UzkLbo v
Figure4.-Assumedvariationof angleof attackgroundrunforswept-wingfighterC.
withspeedduringlandingVt = 1●05VS,
.
Y
am,deg20
a& .—— — —.
10 I\t 7 I v~
‘n\ o I,/—— —v
q=oo
Figuxe5.- Assumedvariationofangleof attackwithspeedduringLandinggroundrunfordelta-wingfighter.Vt = 1.05VS.
am, deg
23 .————
a 15 4_ 10 ~__
ffVn
x fVt
o_.____i!L_ ~=oo v
Figure6.- Assumedvariationof angleof attackwithspeedduringlanding .groundrumfordelta-wingfighter.Vt = l.yv~.
.
.-
, #
8
6
s, ft 4
2
(VJQ21.0
.-. —- --—— ::—-— .I1
103
~,\.
o .1 .2 .3 .4
PO
(a)Unswept-wingfighter. ~ = $P.
F5.gure‘j’.- Ground-rundistancefor severalVt = 1.05V6;T
x, I
o .1 ,2pa
(b)Swept-@mgfl@rt&A.
Edl’’pknesend variou2valuesof= O; ~b = l,la.
.3 .4
~ = 140.
(/)Vnv~ ‘2.
(VJVJ2
03—
Ii\\
o
(c)
\__
\ .
.1
swept-wing
1::-. —— —--—.—.— ::
I
.2 .3 .4Pa
fighterB. ~.16°.
Figure7.-
o .1 .2 .3 ,4
I-b
(d) Swept-wingfighterC. ~ = 9°.
Contitiued.
..
s ,
12xlCF—
10 I
8
S,ft6
4
2
-— —— -..——
—.—
\8
\ -1.
\ \\\
\
‘-.‘\\ .
(K@— 1::
.6
.4
\
\
o .1 .2 .3 .4t%
(e)Swept-ting iransport. ~ = 70.
Figure 7.-
0 .1 .2 .3 .4
%
(f)Delta-wingfighter. ~ -20°.
Clxlduaed.
(q#’fJ2
103—
3\\
o
m f3.-
1::--....———— .6—–— .lt
.1 .2
Pa
(a) ~ = 160.
Ground-rundistancefor
.3 .4
swap-bing
.1
(b) s
fighter B for two valuesofT= O; Vb=Ua.
.2 .3
Pa
= 100.
theattitude
.4
4s
8 XKF
\
6 -
\s,ft4 ‘
2
,
(VJVJ1.0
——-———-—. f!—. — .IL
~
-%\
. ,
0 .1 .2 .3 .4 0 .1 ,2 .3 .4
PO Pa
(a) ~ = 9°. (b) ~ = 5°.
Figure9.-Ground-rundistancefor swept-wingfighterC for twu valuesof ths attitude angle ~.Vt E 1.05vB;T = 0; ~b = I.La.
22 NACATN 4058
.
.
s,ft
8X103
4
2
8
6
s,ft4
2
0 .1 .2 .3 .41%
(a) ct = 20°.XI03
\ \
. \ _ . —\ \
-+... --\
0 .1 .2 .3 .4Pa
(c) ~ = 10°.
0 .1 .2 .3 .*Pa
(b) a = 15°. , .—.. ,
(W%)*1.0________ .8.-—— .6—-— J!
Figure10.- Ground-rundistancefordelta-wingfighterforseveralvalues.
ofattitude“angle~. Vt =-l*05Vs;T = 0; Vb = ~..
NACATN k058 23
0
.
.
10XI03
81\
6;1
s,ft
2
0 .1 .2 .3 .4Pa
(a) ~ = 23°.
IOXI03
8 . (VJ%)*1.00--—_____.s2—— .39
6—-— .%
Ys,ff
4
2
0 .1 .2 .3 .4l%
\~
\ ‘
0 .1 .2 .3 .41%
(b) ~ = 20°.
o
. (c) ~ = 150.
Figure11.- Ground-rundistancefordelta-wing.ofattitudeangle ~. Vt = 1.30VS;
-—.1 .2 .3 .4
1%
(d) ~ = 10°.
fighter forseveralvaluesT = o; Pb = Pa.
.
s,ft
s,ft
10 XI03
8
6 ‘“ ‘i\
~\\\
4 \\
2
0 .1 .2 .3 .4Pa
(a) k+)= p~*12XI03
10 ~I\\\
8 \l\
\\!\\\\
6- ‘I“\
y :\\\‘&. ,\\
4 \..
2
0 .1 .2 .3 .4Pa
(c) ~ = o.50pa.
F\\\\\\,\\\\o- .2 .3
Pa
(b) ~b= o.75~.—
1.0--- —-----—— ::—.— .l!
.
.—.
—
.—
.
Y.
—
Figure12.- Ground-rundistsnce for delta-wingfighter for several.of brakeeffectiveness.Vt = 1.OXS;M = 20°.
●
values
, .
12
10
8
S,fi6
4
2
xlo3--l----
t
(Vn/%t)21.0
----------———. —
—-
0 .1 .2 .3 .4
t%
(a) 9?=
Figure13.- Effectof
o.
0 .1 .2 ,3 .41%
(b) T = 0.025W.
residualtit on ground-rundistancefor delta-wingfighter.Vt = 1.Q3’’JS;Pb = ~; ~ = ~.
mapsdcun
---–-– KIApsup
0 .1 .2 .3
\
\\
3\\\\\
.4 0 .1
‘\
\
.2I.&-1 i%
(a)Unswept-wingfighter. (b)Swept-wing
I?Y.gurelk.- Effectof flapson ground-mudistancefor severalVt = 1.05V~;T = O; ~b = Pa.
.3
fighter A.
alrplatles.
.4
. ● .
-.
,
12
10
8
S, ft 6
4
2,
03—
I
\
\\\
1\\\\
0
(c)
\
L‘\ \\ \
.1
swept-wing
Flsp dan
–-–--– m.apsnp
.
.2 .3 .4
Pa
fighterB.
m 14.-
1I
I\i\\\
0
(a)
Continued.
.1
\\“\
k\\\\.
Swept-wing
.2
* t
.3
Pa
fighter C.
.4
k?
28
.
●
s, ft
I2 xlo3—
10 \
\\\
8 \\1\\I
6 ,
4
2
0
T‘\\‘, \
\\ \
.4.1 .2 .3
— Flap*
–-–—––maps up.
.
%
(e) Swept-wingtransport.
Figure14.- Concluded.
.
.
?NACATN L058 29‘K
“
.
s,ft
(a)
.,
s, ff
12xlo3,iII
10 \\\\
8 [I\\\
6 \\\\\\
4 \‘\‘.,
2
0 .1 .2 .3 .4
Swept-wingtransport.Vt = 1.2VS.
12XI03,II1I10 iI\\
8 \
6\ \\
4- \\
2
0 .1 .2 .3 .4Pa
.(c) Swept-wing fighterB. Vt = l.~~.
1
1I1\\
\
\\
‘\\ \.
‘\(\\
\
o .1 .2 .3 .4w
(b)Unswept-wingfighter.Vt = l.~~.
b Figure15.- Effect of flaps onground-rundistance. T = o; ~~ = Ma.
s, ft
‘o .1 .2 .3,%
(a) T = O.
Figure16.- Effectof flapsend residuaJ-fight.er.
,
.4 0 .1 .2 .3 .4t%
(b) T=
thrust on ground-rundistanceVt = 3..05VB;Lb= pa.
‘. ,1
.
O.wjw.
for the straight-wing
. r
!2