Part No. PWA 109702 ====:::::==-=-- PWA 0 I. 100_-:1

-THE AIRCRAFT ENGINE AND

ITS OPERATION

INSTALLATION ENGINURING

February, 1955

'_ .,..., ...' 11' 'HI.. , , ,.._,. ".~ .a.-. """' ".,..,.... __,. ,.,.. ...., IfJl

~.. , """ ,,1_,. 0 ",'" "",_,.,w ........... r~_" 1fU

-THE AIRCRAFT ENGINE AND lTS Ol'flRATIOS TABLE 0.' COXTt:S'I'S

-- TABLE OF CONTENTS-

fOltJo;\\,'ORD _ _ .. _ _ _........................................... 6

--

PART I

THE AIRCRAfT roWERI'LAST--

'('HE A1RCnA:~'" VO\\fERPl..ANT _ _.......................................... 7THE POWER SECTIOS ...._ _ _ _ _ _ _ _............... 8ISSTRUMENTS AND CONTROLS_ _.................................................. 10TIlE ACCESSORY REAR SECTIOS. THf:

I'OSE SECTION, A~'D THE PROPELLER..................................... IITH.E I.UBRICATlO~ SYSTt-;.r .._ _ .._ ,............................ 16

-- TDE COOLING SYS1'Ilt _ .._ _ _.................................. 19

Tnt INDUCTION SYS1":\1_ _ __ ,.".,. 2.&I. CarblJnttion ._ _ _ .._ , 262. Suptrtharafa.r _ _ _ _.................... saS. Du

- - - - - - - ~- - - --

~i____ ._. l

~.7

c:nO\:ND OPERATlOS -Wann-Vp -)lagJ>T.... I__ t..... ("lombr. ~toI Fl'p!1.CTIlE SINCLE-SJ,~(;g ~lIP.;RCHAR(.EI~

1. C!'OuodHooitinl2. Low AlbWcJ.3. lUg!> Altitudeg'DI"'S~ -r..-o-Spe

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"RArT a WlUl"EY AIIICJLUT FOREWORD

- .OllE\l"ORO

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Tht atre-rnfi ('fl~;.De is dOlgnNi Cf)poetr Aln;,...'" :n ftight~ Itg conItruet~. jrutalkbon. ~nicln2'. a..ud l't'iNUr p'l"Mltnt many inu."n."I>tting andimpol'lar.t J)rob!~w;but its 3ttUru ()pc"."on IA.naturall,. of n".Qt'f; imnltdi-ate I;C;IJlCenl to th.e PilOlo. A numbt.-r or ,.xc.... hard'booll, and nanua'JI areA\anab:c \,h~~ dtscusa thf, prinnpk"t: of ~"tr1I~ d.. l", and inAtAJiAtion, nnddCllcrlbf. th e ptodurt'$ ul nminlenar.Cf .. net o\'crhaul. " $uppJcmcn:t. totht, malijrial, it I~ th,. pu~ or Ihi. buok to dlJlC"UlI,Iht l)Owcrplatit Ali kiUMIiO'lhlJ(uuil. and all Internal fIR" of (h~alrel-al' Inwhleh It 1" in~trdled.tutd so to flro\'ich- Abaai, for an ul1dcnl .. r.dlrM of AOund oJ)Omllojf preetlee.

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The fm part of lho boojc g dvut4fd .0 A ~rtpdOI\ of th. bRaieen$lilu: .uetKlrl;l and ",qattm!l'" 'CI'hk'h tochcr Mlttlel up t.hfI r>Owftl'pl"nt,alld dlll('un6 them in rdatlor. to tl'.c chUfO,..nt h\lt!f'Jnlt-UU and colitrollO bymMft!'; of whkh the- pilot rtt:ULah ... th~petf4'lrm.t.nf'f of hit tflAine:. The'.'

-TIlE A1IlClUFT l'01I'ERI't.Vn' Of'RATlO;\ &; DESICN

1

-PART I

THE AlRCRAFf POWERPtANT

orERA1'IO~

The.lft-tatl ena1ne and Lbe aut.omutnl ..,alne.... fundamenl8lly ali~in prlnti"", lAd -rn.Bu01 ton\'tft the tMtnleai I'Dtr'17 of .. mlXt\l.reof futl and aIr into IUetul .ork by thf. umepruc: .. "" of h'!tornal eombUltion. Both lhlrpoorite Llle .IIime bask ~hanilltll. Knth '\1m ....,tht 1'I10tl\0 po...,er tor the vehittG. In ..hkh the,I ... 1lIl'Ilallcd.

The operAtion Of LlI(!,h,tralt ,.nJtfne. ho_ ... "",fllttflrt in muny Wa,yfl hom th... of the: ftutomo-bit. ,nltln e, TI\Cperforman ~uln.-d of 1M lat-ter I. rvlatlvtlly limited. a.nd w ht m., be ""'-.roo,tv uted to InJUre w-kSf ma "" at .'Hy.E,.n thf untntormed drt ....., ("IJ'\ do hUH to.buM hl~""rln .., "nd to lb... utent t1M: .t.I~.bll. pn..rp ...n~ .... boon -'ooIp_r..s. - B7__Irut, a ...Kt. "'1"10 of pc.rionnJU'w dt1n.a.n4td"f the "lrcra(L en6ineo ,,'hU. lb tJ,ht of theVlI"'flrpl",nt mu.t n~.rH.Y be kept to minl-mum In th",lnter06t' uI. 0\,.. ,....11.mdf-nt'1' or the.lrJlIAn~, Accordingl)', tht open'lor mllJt .uhAll~Iute hili IIlI(ler6tnndln~ atld Judgment tbr rMrewflla-hl. aud IIolidit;r or ttrudurt, and. in placeot "tootpl"OOtina" the .ugint. the Optratur muatb., "toulproofPd.tt instead.

).:n.,.lho Ndup. or ,he reIl.ricUOGl pl_....t onfnafin. oPf'ration. an of Ultl.,. pf'k(kallukratto lhl' automobile d.river .aJ..Gce In tf.. C"OafW ofordinlu')' drhinx- he cannot ee.t11.Y c~ ~I mita. On the other hand, e.rtrIM rafln .., mu.1I... Ol,e of tnlo1 t\nt concern, of the ilJrplant' pilot.II ~ Pf'I,,~{bJcto operate virtually Any IJUrerait"'110"1110at exee.!IIIive poWflh. vwJ in mo6l an-.d."nC'('8 there l&uoUting tn T'e'l'Jtl'aln the oJk'ratortrorn ex(:eeditlg ttl(' limit.. !let by lht' mtlnJ'J u-(~pt h4 ulldf!Mltanding and Ju.d~m.nl. It theJlllot makes UM!or engine tpeeds and c.rlinderPl'\I:'o.UU'"th:u are abow the rated IImi" he isftly In" upon ntJU'ina of safely "hkh m-.,.~dan,,,,rouab" D&l1"O\!>". U he laib: to obItn'e C),En.-dctrhud or oil temJ)eruu.re bml"" Of" otwn~

.',thout "pm to oil and fuel pre.".u,," or tofuel..a.i.r ratIO. h.. I.J t,..tifll' a si1U.aUon that ("An0tI17 ltd to kM-tnd ,..liabilitY aDd puuiLi ~. t.&tUN

." ..... lua.. an au~,..ftenlOne tJ~ pilut l'_1"",

rRA'M' & WIUTNEY AIRCRAFtPW'\. 01. 100

THE roWER SECTlO)1

I'~ A.~OF1r.\(."'1'IOSS

A. t~ n"mlt hnpbts. tiN" pUwer .eetion b thtitlon or the fOr.ginein ""bi~ Lbe poC'tr I,d."...:IOped. und "'hien is the liNit. to reeelee lhf'ImrllwL ut ttMt h:Nlid.cleated. It con~i~ ba..Ie-nil)' or thll iollnwlllR au.:mhties:

1. 'ftl" Cyll"d4!filThfl nln'ra(t 1l1ll(lnp. l$ a. he.t. en.ri!'!('which dtrh',,_ H!'t power Irum the bumin. nf a tomhu.,I!)I. midI)", (If " ...&olin.. aJld afro Tht rue'"tilr rh ...rli!'fiII" J,",it,.tl U)' a "park, and the h#!at(#l\lntNi b)' the bUl'nlna: nf It.f: fh.M.rtll: .C.."""do I'" ~...... l"""teI dUrilll< 110

THt: AIRCRAFT rOWERPLA.",. THE POWER SEC'1'I0N

......,.mbly.s a eonuque~ of t&e high rota-Ihmai~ of tht t'n:cine.~re i.i eee ma.~r

/~'''..-

-'''HI articulMlJd rud IWItmbly .00: one c.r.r.1cthrow (or 'ftC'h rew 0( C'flind...,.

- $. The Cfllnk"h.hTb nftflklhlrt tkM"N ctwopowcr~.nth. ryh",,",.. tram lh. muttr aM anu:ultltdrod .~I'nbly. and ,ra"..ftnl it t)UOo.lb ,.r

""''''_ JlM/' '. "~II.r,-u-aIM tu th... ...,..op"I"',. the lu~er. tkw.J~.,..~,.tin.l l'rwduuUsn'l. the oil aDd fUfIpum' ... the tnla"W'(I)t, the pI'OpI!iler &'O"'"UJIOr.the ,t"Of'nlor &nd ott,..,. acceueoOa.. Jt .. ~~ff;t to 4"Ombin.boo of C1!fttrtfQDI. ftClpt'O-catJQI', .ud P,...,.Uft' Joadt, wpt:.Mr ..nth \.01'.tJonaJ _, ... ~

Tht. t' ",,"ca_!IItTh. trankcalW, rtn ..r-.JJ}in t.wo or more parl.a~hoUHI lind 'UP-Purtl'l th.e aa.nk$ha..ft, and \0.1 .rt ilUachfoCi the cyLindel1l and lbe JXIi!if' anduPf'n'hAr$C(:r huutling .st(tiOtll. Its hearinn ab.IIOrb lh .. (Jow(lr.produl."lng loads from the pis.ton .. and l.:unlulhRtt.

('OWER ~t:(""ON CO:>."TROL

Whi.l ronchtian~ Ir: the PD'\\"t!:r section are ultJ... tfoly the duet ~m or the operator. tbu_,11>1 .( til'" .....Ion Iino! dirod, ..nd 0IIIy ....ino""_.. Ill. eylinder bead tomptttlurerare. III tlttuaUy eeeneeted to it.. Instead, c:on-trol :1a t'{maMd thmugh ollil"r pam of thepowerplan:. and the effect. of tbi, regulatinnare mcuurod Indfrt'lCtlyby \'arjou" in",rumt:ubwhkh tnd'ratf' cnd:ttonaobtAined in the noeeond ro..r ~U4'ln. And In the lubtirJl,ting. coothl".indurtJon, l4nd J,nition 1yat.umM. '(IT f)Comple.t'ylJnd"r I,,...,,,.ore .. 111"0('ontrolled by UtU Lhl'ottl~of the Jnduc:don 'Ylltt'm und by tht'! nropellor_PHd rtt\'f'rnor on thft no"f $ocLJon; and thC!.epre.ure ..... m un."tl in tf'l'mll o( thu reert-Ina" (If t.h4'mar.It td flrl'~.l.ut!and rl"'1JlI~LurIUr twn""tAtur.: PJC\'" nt thp, ind",cUon IlYl'tem(CIt trot ~1"lu"n'H"t('r JrIillJr' frnm the nUM JltfC~tlo

_-

L

PRESSURE1

1.

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-

--

COMftOL _ .... _ .........

O-'"....4e ..............IMfUt.a SftQ...,. _...., .._ ...-........._o._ _,.....,._..., ...._---.. '" _., __....._ .....

.... ICAftOH_ .... 1 ,,"',

"'UUU ncn. c,w. .....I. ,..... ....

~.-.,_ ..........-::;:::='o\ ... _~.............. -~........,......~

....... c_.....,....... __ .......- ....._..................-..""'"- ............ --~.,.- ~ .......... --- ..,.._. -.......,. ---...... ....-_ -_---..--CHARGE TEMPERATURE

(,01111101._ '--" _~,.. ...,._.'illlete"fMlfII _ c..._ .....''' ..... noe ... " ,.. Mien., .....,.. .,.._ ............................. -, .....'" ........, ............. h.ioI .. ~_ ' ~ ' _.,, __......... --- .._ _"... _ ...._-._.f!IiIt ........_ _

MIXTURE STRENGTH

..... "noM _ 0. _ II!oA ......... ....,., _ .. .._---.....".,--t ....__~ .... _ .. -w_.__--t. '-""Wf ........O_toII4oo..:ll __ ........... _ ..... _ ...........

",,1,00.

1 1 _,I r.. 110 """ .. I" ,.. ...... ., I"" ....... _ _............u 4..

COl'mlCM. - .......

... ~notI _ ....,., .......

"""lOtI ~.cnl. t_., ......__

.. --., oJ"" ...,_ ..............~ ...-....._.-

SPEEDeOHTlOl _ ,t., e , if _IoOt.,_I;,.....dINOrc;"TIOtf _ r."' .

L ....;,.....c.-'i ....... .... ", , .., tI- '-I.d .,.;.............................. " "1 ........~ .... )oy " feM"_ " I~ l,... _ " ",1.. n..... ' ..-.II,.~ .....to.c.. ..... _ _1_ ""11.. ,,",'" ..tl,1... _, """.. .,,,,,,,,'.'h'''''''' to.__ """...... . _ ,.._ rK_" b, ....... , _ ."';.~_

UOCIO .,,,c;r$;

L Po .. ,.2. .... , _~ "III", S,_",

t ~.._ ... ,.......... .........,...._ &11 .... "',.. _~

... c-to "-"' ._ ' ...._ tl~ ~............. ...., ,,--,. " ..._ ....... Ni _ '1.tV to _ ........ --.0r..I0 100410, ,"'to"" _ .;,;01 , '.. " 1>, ". .,

CYUNDER TEMPERATURE

COHTtOl _ "..... , "" .......... It ..... 1M It,.. " ..." ~101.. ., .. "" II....... _1 "_

....c.now c ,. II "'''',....... ..C""'"t u__ "' llcnl

n. ~".... "".....C,-.,III " PI}I 1111...... hoi '-'I"" .. , c,..... w....... PIli.' "'""a. , __ , .......

AI _If .."..Ctl:

t. no. ~"' .t w.. ,..t s. u n.t............t. ,_, , _ """'. C" 01_ Ski .............~~o

.,\" ,II _~.v' ,o 'c I')

10

1 Tilt-: AIRCRAFT I'QWERrLAXT ''lfB ACCES.

,~'rI/-, I-

I :

I \I

I'W.'. 01. 100

Cronk.tw.n puww is. t:nU\..r,;r"_i_ttNl t4)f'WJ.rdthrouab lblt nOM:a.QC":ioD ;0 u,_.. ~. Ttu~l~fWI@I(I(:Uoc:houteA lb4: proptUerwt rt"du.cticm$(,'1'",n", .. "d OIW ur mute 0l1.!(2'ftllP- po.nnp!. Itprovid," A pewee cakl'"-olf(()r the attuth~nt of

f'J1'Optl!..r ~ he. ltC'l)pltr Nt.ol" drh'.; and It, t~T"nl.h,. mount:"r p:ulJ and dri..cs for eN &".vr ... pumpa.. tho nl ee-~"~~ ,rLU'Dr..M .rul(Uillrlbl.ot.otAr. ,'If p~t.r ",\~rnor. aA4l fidLl'r.'-'C"...,." ....

nEIIt ('rt"", (,tlMllNU -Otlln: 11,\1lOS

I. mrtct O,lu~JllAliuna1u\l' wh.inKIr.~find flTulw!lcr can 1)(' filM'.'\1) UIK"l'.to o~ clTkilmt. ~tlOud,., '["(If' t'l'.llll~of nd\04",Inn Jrf'IU' fjll,iu,. i!t 'from -t:/{ to :$: I.

I,,,II

,U

(\I \

\III

I

-TH Po AmCllAfT POW1!IU'LANT THE PRO".:l.tER

THE PROPELLER

The llrwcl1er i..E!S$E!ntiatJya ~&c:.I tor eee-\,..rtlnil .hM.Cl horaepewer into thruA. beese-pOwel". It, i" quite JlOt'.~ible. bOM!\'U, tor a pro.)J('IIt'lr' W ~lI~lltirtlmwy be dlvid ..d im.~ r\'ll4!tal tWII:

I. ~".d rltth

Th .. pltfh, I)r blade ~U;lfI, of LhlJlt)~ ut."..,.ter III Ilxed Ilnd cannot lMli varied in rUahl. (In"gmt! moutbod by .hla ')'1)0 01 ..,.,pon.r rl .. u ....nbll or tbe rpm - t@., ~p .. K X rpm' Ar.conJJnlly. fQl(' any ,.iv,,, powu tl'w-ft b C'Ot.t""J.II,Uldlni rpm. Smte power can bf> "'I'Ulntedhy mllnitohl pr~..,un onty with Lh. '"'' 01ht"U"tlon, prGpellut .~ h C'On(rol~ b)' Ih.thruLLlu.

2. Twu I'ulfltlooA hydrAulic mecha.allm. Oillemtfld by ,n.,lne onpn;..u~. mak." it I)OlIt4bl.t ror thtt pnot to M-'l In lla.,h" ftthe.r a hlah pttcb tlO'w rrm) ora 10'0\'pitth (hib rpm) poNtin" (or mon .trl-

nl. ..p....d rqulation,. A ct-r.d powtf ma,lh 8 bf obt.alut--d with t.." d d'tRh\ combtna.Uon.ot rpm and ma.nituW Jll'URrt: a ha.h rpmIl ! luw manifold Jl~T't (,It tIM OI>I*Ilte ~blnAHol) III hixh pitch. In bclth p(II.Liorll e~",..V'Uw~rAnd, h~nCf .!l>C'N are teC'Ul.atfld 11 Lht-throttle, "" with a fixed pitch pruP':Uer.

3. Vnrhtbl4! PitchA hydrllulic, electrieal, or mbo.ok,.1 meehan-uam permitt' the pilot to !et tbto P"'ptner blade..!'ule In nighL to any desired a.DIC" onr a ton-oId.rablt ran"" ..... the pitch of the _u.r10 In"""""" the l'eSi_ oUond to it by dieafr bfocomN' fCrt8.ter. and if other racton.. Judt

.. awUf .. d _.... ....".." UJJebanged. thorpm wilJ ctet.t.ae. ec",~e1"'8ely.a ~reaH 1npltclt ,....1 '"Uti.. in a higher rpm. Engine 1Kt"t:tand 5pl"'od. aITfIrd!n.a1y, no longer bear any flxedre;adoo to UI'W tlnf'ltl':er.

Tho nHu,t .. nL "ptoed propeller i!\ n \'tlrJnbloplteh pruJ",Ufor In which the regutatlen of thopitch i. automatically controlled by I. y.u~'cruurte .tuch a way that the rpm i" mnintaiucd un-chanced at It ftturc ""Il'tted by the plloL.. ruard-Jes.s o( ('han..., tn ,,",Wff Of' manifold pre....u,..Su.eh an arranl'\:~nl ruff" tht .truoletlt poa.,l ..hie IInHI1I:ty of "pcoraUo.l\. 001 it pIaoq upon theop"aWcf' tt:fo rwpondb!btY ttl tboOIUng a ,,"I.

balallOoId l"Umbln.tKlf'l 01 rpm ud manifold f)1"U-o.. rot to obtain A d,""lrNi1>fl\\'Ct' Ilnd, at th~fll\m.Clime, ma the mu.t f'ftk-ient ulJe ollx>tb 8naine.nd .........I..',

An exwn"Jon or the vurluble ptteh JH'hlctplonu.kea It pu lbh, t.n !loft tho pruptllJet hlade"rouahly U..,t to the line of lligbt, and 80 JtODtM ~nliM whllfo 1n the air. Tbl$ III known ...(ntHri ... and I. often f(IUnd u.&c!fulin (lmt ....fVX'1~ ."JC:h tnyoh'., fnalOt IaDu", \\"th lM_ .n tho , hortd pnaiUon, tbe drq ol.h,~ I while tho 1>OIIibili'Y 011.,.lhu cIa~ to M&n:n.(t andPO~lUIt (roma -"incImJUi"," ", ...ioe It pn.-vented. It. i. Ill...,pc:lR.._"I'bJe whh lIOmet)'pc.t ot. ~nerl to tu..rnthe bladea put f1l1l low pitch into n rtJ\'4,!fl'edpikb pullLlon. thu. tc\,l'hfittg thp.thru.L ut thepropcJIc.t- ,. feature ,....bkh j" helpful in maneUa\'eriD$t aplAno On t.he water or Ln~kin. allairt:nd\ on t ht'll'n)uJ)().

lIP)! CONTROl.

EAino IJII!O!d. C1t."m. U Ihus controlkd La ...ofIht Iono..na...,t:

13

PRA'rT & WIII1'St;Y AIRCRA.,. PWA. 01. ino

i1. By the throttle !t."'''f. in the ~AlIOof fixedpitch pro()t)ltc($ (t>r the hhth or low pilehl)(lF.:tion U( A t\"Oopoddon propt.Utr) ; or,

2. By the propene,. l'O\"'P.mor~tmJ 1eTer,in the ta~.:of vtui.bm pilch pn!pl"Otn.

(!Ullllt(lllt "1)flltd pro'Pellt'r in~ta!latkm. ece-monly i!'.cluOO A lovnrnol' dri\'tn b)' .. Khr tni"from tho ~",",ud,ah: and mout1ted on ,tit' nc.riI~.'ttcm. By dlN('ting enA'lnf oil undt:r hi.... pret.."UI"'O 1.0 tho m"C'h.ni~m cont ..tned III tho prOC)eUer

hub. or by contrvlhnl' th l:trieaJ tmp~_lVItto a hUNMI,*:d motor, the ~nmor I"tautate.the 1)It("h or I.hu propelktr bJodM in .uth " w ..,.I\JI to n....Irualn a c:nn.llLIUU.I'1>m n'!,,..rtbeM orpnw~. maill10ld pre.._.... u.nt, or altitvdt On otftuin.taliatiQQ:j tM propellt:r iue.fincludu tbt OV.emct- All an Intt.,..J pan f>t U:e hu~ and 1McumvlelC control flylA!m. Indudinll t'M' 011SUI>ply. " Jl1df'pendlf:nLu[ th~ fqinc.

,

It a.houblbt nnt.ed that. if the: pnmor I' ....to n.-aulat..e at a high or at maKimum tpm. Andthtl .",Ino Ie:nnt do\'cloplnll lumcicl:nt ()owtr torurn lh6 Pl'Optlll'r .1. tM. 1IIJKl

l1l11

1l1l1lJ

1

THE AIKCRAI;'" I'QWt:KPLANT rns LUBRICATING SYSTE)I

THE LUBRICATc\G SYSTElII

Oil is onen rererred to M the ..ti{~blood ofthe eualne," and b)' ll.nru

PRATT'1t wurrxev AIIlC'.RAN PWA. or, 100

16

t ,I 11 l{ I . , .]11

LL:

THE AIRCR.UT POWfJRPLAN'T THE 1.1IIlHIt'A'l'IN(; sys'rBM

2. 'l'he lubricating $ystem cools part.s of the en-gine that cannot be cooled by air.

For example: the piston. wh.ich form..'i oneend of the cnmbu~tior. chamber. isaubjed to themn!lt intense heat present in the en@'ine. To coolit. a ~pra)' of oil il'. directed to the under side ofthe pteecn through jeb located in the ~ranlt.~haIt. This Npny all&o tubricates Ute ey1inderwalla and pitrotonpins, and asSi8t~ in tooling tb6

lower Portl ot the cylinder w'nll.The mutu rodhMrinr j"snl)thfll; eXAmptp..nf a]'tart thAt h~bnthcooled ami luhricated by the 011of the a,..Utm.Approximawly l()~;' of the heat rel"aaed bycombustion ill removed from the tmgine throughthe lubrlcnting y&tcm.

3. The lubricating aY!fte.m turni.he oil for theoperat.ion uf vmoutt unit. and aCCftSlSOciu,such a5:

8. The blade angle '..u.rying ma:hunmm oJ thi!hydraulical.lyo(l-perated PlOpeUeT. (10 thisinateece engine oil pressure ia boosted b)'the propelle\' governor or by the featheT_inK pump.)

b. The impeller drive clutc.h~. variab~ sparkadvance mechantwn, m.anifold preaaureregulator, and other untts, (Units webas these are operated by normat engine oilpressure.)

CONTROL OF OIL PIIESSt:RE, TE!IPERATURE, AND .'LOW

To perform ite several illt\etiolllt. sati'(aetor~ily.lubrieaUng oil must. be:

I. Within the pruper pressure IimilM. Jf oil Tll'eR-sure is t40 jew, oil mAy not reach all p:u'u ofthe eng:nc. win not b(> (ucl'l'd In between bear-

UASTI!P /101)-'1"- '

~.~)--~t:'~~lrur ,urilu""4)5. or 1)f'C)vdt;!ulluquKte Hew tlIli.l'pm), 'or _Una-.

U oil presaure a to. high, oil lO4ka ore likelyto deve)op and oil ccnsumntron to become ex ..eesslve ..

Of the "'ariou, co(')tpjt g;.\ges, none i" moreimpori;aJ:lt th:m the oil pressure gage. Lul's uCoU pl't".5.Surelis an indication ot the failu.re of theoibupply, and wit.hout Jubrteatlon it may beon1}'a matter of seconds before pa,l't~ have beatedand burned, bearinge have eelsed, and tho engineis brought to an abrupt. halt, badly damaged.

17

PRA'IT " WIll~EY AIRCILUT PWA. 01. tOO

,",It om",,"oi ... tb. Tital ~ of 1Uk-ic, tbe proper oil pra:au.n.> c.IH!tb prior to tab-otr. An 011JlN'Mure ~.Jd\ah~AI. an uppwlIml~ to tn"ine oil pr(l&sureC~ tbe .nll". hhbOunwormed up. (Because of the ytaco.hy ot(old vII. prC88Uff!A of aeveral hWldre fona1flf\ th. fi[aMf rt.dl~ will "ury_.,. WI.II """lIlilll: oo""ltioo. a.d wW no~COtWtit ...t.e ._ .ta,," .tandard (or devrrn'nln,til. cond'IJn 01 tho oil

If. dun a Will ..... th wiclt ...... &bult ....Iho W __ nol rTO\"hle rudenl .... 1". ..-tor no.. of air m., be obtllnod by re-dUar.., tt... a__ oC climb And ao IncreAJ(nart.M apeed. uCtM airplAn A final mOons o( lower.'- oU kmper"tuN I. t.u eeduee power. 'I'ht~ahou.kt be dont' by lowtrln, tho rpm AI well AI'!tht manlCold fJ!"f'1I.-Ut"@; ,dDOO fricti()11 and oiltt'.Dl_p

LTHB AlRCRAFI' I'OWERPI..\NT

THE COOLl~G SYSTEftl

J(N.S""CAA*I(#tHI,

.m Ior mak.ing a prac.r.cat And durable connection.

The temperature recorded at either of thesepoints i!merely a reference ~I"control tempore-lure; but so long u it is kf"Jlt within UtI.! pre-sertbed limiu. numerous testa have shown Lhfttthe tempernbJres of the cylinder dome, Ute ex-bauat ".'\"e, with itl!1- seat lind guide, find thepiston will alltO be within B s.&Lilffactory rnnzc.

As ... rough exampJe, it can be jn\tl;gil:cd tht\1:the hou~huld ther~.o.lJtAt hl'lSbeen p)tttttl'll\bo)\,e

a radiator. In order to obtain the desired roomtemperature it t\'m be neceMAry to set tho U\Cl'-mostat. (ref_renee or oontrol tl:!mperature) toIOt'OO hlghcr tillure. Tho thermoeouple 1& tliecylinder. thennoatat Indieatnr. ]tR limit is(l$tabliltiled, arbitrari)y, inorder t.okeel) at :-lOUd-factory tempentv~ the vital pol't;ion~ of thecyUnder whose temperatul'l! eannut Le meue-W

THE AIIlCRAIT roWF.RPLA.'iT THF. CYLINIJn COOLINI': ~YSTEbi

1,llIIITL'it: TE~lPERATUR

T,..., limitina: cyha.@r h.e..d kmperataT6 aftUJ;UIJ)y found in $pfdft"",. to,I'ttnl,lr with tulM mtan. of r"~lIlallnthot aJl'{'.ow in ""'PQr.Je to \Ar' inlt ('(!""dlUOft""

"M .urate art''' uf the t'yJlndon lIXPOft.Cdtothe ~Jn* ..(rnow I. fnc:rf'A8Cd 1.1,)" th~ usc 01cooI{n~ " .... The ftri('itnty of the tlru ill IntJ"f'Ucd. UI) to terU1n point.. u dwy are madedNptr .beI .putd MuN clewl)' Wu.th.r.

Not mall)' )'~ lA'O tll,afne c()ullnl1 WClI MecompUI'hoo by 111mply huldln, tho c:),fhHlen tllLOthe~" "hJ.s atrlll-l\M'lJmfont ".tI ..ev.. ,.."J "hort ..(oaun.," Wcile ~I th. ...1., nl th. palh of lbeD,JifWl' ~ bK_",-"CInIhe ()lUnd..,,, of 1..btI en ...giM. onl, ... mall POrt..lunof JtCHrn. etese enoughto tM nn. La f'f-movc much (If th6 hOM. Thec:ylfndt"rt" I,Ir.Wl)10tlun(l\'f'nly. tbt T."r portion,of..ch Ont Umdin. w run h.otter thin the front.n.. turt.ul ........... t

PRATT & WIII~.:\' AIRCRAFT PWA. Or. 100

_---

)'0"" )'Ui.:~ntlyintcr-cyUndtr and c,)'Undtr hoeIdbafflA.:. n.H' bef>n u.Nd lU tOrte tht C'OC;JlJII. aiTInto duw lv,l\j,(\ ""h .U a-&rt. or tbe e,Und,.n.tn thlll way fh~ .ndrc ...Irllow ... ulld to Can')"!.Itt,! h\:u\ "wnl (ron' the tine. A.khouach tho ,.."IIIthUI,:U un'cI't'd by ttl. b'lttlt. .. and ftn. to theJ*8SRJl'l. (If tht cooHlut .rr dt1'lWUU ~.\ anappn:ch.blo PN'IIIloUI"Iclift'~rtntlaJ be m.LIDL&tMdiU'rou lhv entf". lO obLatn the ntnlla,., .'r...

no.... the "'umo of e001ln" ..Ir .l"6Qulredt. muchfflduetd by the uM ot. I'"ros.. rty d('i.it1)ed ')'Iltemuf 6t1\fI(101t"W r...dthe rt4uluf\I me fa a

11Cr:c

TH f; AIRCRAFT roWEIIPLANT mE ('YUNIH:R COOLING SYSTE\I

J\etu#U.)',on.,' about 10"( or the air In 1MJMuh ur the enatr.t , .. fun:wd throul'h eM ro'frllh. ~Ml\;nder "ulnJ .rnoothb Ofti' t'" out-...dI: of tht ('OWl.nl" A ~It there: La httl.1,"OU:hlJC dn..-thfl PIJ"I.'" ton~med in rouluur.mount." tc rUiJJ[hty31 .. ot 1hebl1~ PH'"l

PWA.OI. 100

~t2

2.. Ry Air "'PHilAt:y uriaUon II'!-tt: ,forWard JlpMd uf th If ..plWlO Atf,pd411thw p"",,~I,," ., lh(! tA,.. of thttna1nft ""d, btnw. U'" mill .... ,('". I*$( th.t-yllJul(.Jrt. It .i"'lJ'l""t loAn btt Inn....,,'" w,lhou\cullin. uJ'W)nlh~ 4.Ir,I"" tor .drht nnal pu"trtor namvk, by rlHrMJtl1Ut Ih.. r,,. ul (h~th. NoIJult","I h4r Ii nlOP IfIIYU\~ tf'I(Iilnlr at11,\\ (ltalnt.

01'".:11 TEMrr.RATllIF. (ONTHOl.llThl'Jrl'l ar" ,dill,) {We') wa). ur ('nntrolUnac 1M

tfomper'ulUfiJ 0' I\n t1t*lnCl. ",,;lh"f ur whleh.IIt-rletly .ponkins, I" \llTc~f

--

TIlE ,\IRCRAJT POW!lRI'U"T TUE L~DUCTlON S\ S1'llll-L CARHU[U;'I'ION

Do"DUCTIOX SYSTE11

FU:\C!'IO!l'The Iunettou of the fooU(tinn .y"tf'm III to

Il"UVtlf II combusaihle mtxture of (u.'and air totht I:),Undtll'rI nnd, !'ubJect to mttlJl,lmL f"antrofb,v the Ol)lijfl\tnr I tt) dpUvtl" the ('hAr ... :

tl) at the prOJl'."l'{DeHi, .....bo 10f' .h~ particular t}-prttf C'IPffl'tion drmandNI:

(b, In ... tnr~nt q~:n:of~ tc mHI aU pu.tr.-.qui """'A'nlS :

Cd at I kmptr.lt'oJ1"'t that .. 11]IrtMll"t' tn".. knt('I')M bu..tSon :

The 'nducU"u .)'.d~~ om eonvenipllUy bt dill-

-PRATI' &> WIIIT:-t:y .\IIU;RAFT

"II~RT ('ow.m" and UEST[CONOllY" MIXTURES

It III. powo ullla' (".. b """"""" ..... 1 ODdrnm uCan el,vitllJ are kept CClr.slanL. and the miXture .ttcngth hi varied [run). OM \lxLteme to.,,.Mhu.'l will bit !ouc.dthat:t, The mOir.JCuki l'~ nrclUai'N to ~

rluee I.h" Ki\'e~ ;M)\\'Clr At. thtt tHif"n rym w,nbe ut Iimlnheum when the rm:..air ralto I.,)t~ "IWj(C of .11701 - .~l By definit.&uf\.07-1 rut: -Ilr n.ho ill "bn .,....t l'I)W.r'mbmJI'\! and .080 tlk'll-u:r n~~tOit "rk:h1Jl!3t nower' fr.hu.ure. Any :l~Ixt\.lN w-t~~n 0701 and .Otto fud.-ot r n.t!Of h. a"beat rn~'t'r"mxtuN.

2. The I1UlUlllLyM rud ~1I~,.d \0 prod~(hl'l gfvcn rower At the "h't!! '1)m will bftAt I:t mmlmo1Ol .."htn the ~UOI'I'i.t ra{~ "upv""',lmaltdy ()~ _"ft tb" "'110".~d.AdVhtlto tlflt.tirlR~ A".n c,,"QC' p~on Nt"~mp'()~"11. '1'''.11'I", lIuulr h)' d"ddUon, tht"lJt,l!t (l(uJtI,my" m ,tUN.

Th~ rei ... on I:K:t"'Of'n but J'I)Wwr ar..d ... tuc

TilE AIRCRAFT I'OWflRI'I.ANI' THE ISUl:CTIO~ SYSTEM-I. CAllBURETION

J

-- NORMAl.. COMSUSTIONwill tx-aln spol1t"neou"ly 8.nd l'imullKneOuaJy

thl'QU.l:--itOUl the unburned charge, Tho "~nlt I.t ,uddtn And ,'Solent foxplosion of the thttrllC

Xormnl combustion ia nlpid. bu&. it 1$b nomCAnIJ M inS{1I.nt.anfOUt; ~xplOM-ion. The dtorgeblU"U eveuly and ..moothly, the Hame front- adWln

PRATT 8: WHI'I'NEY ,\IRCR.H'T PWA, 0[. 100

bmdlll 0., e1'oded l>llrUon __or vaheJ. pl,to". And('ylhul ..." he ..d."A. dowratlon can"", Uluolb' be ...._ .. ..s

r._ t~.rnc:kpl'lhro.,.h"",",,_ ..... d.'_'uunpcC'at\lN\ InOrr-h",."erwhich .~ . te. tho tha'V. lemptraDU'fIm"klngue .llUAtm wane. A. wit" praeUcwly All en..&ine dlffi(.u1Uo.t. dft'l'rulfNI rpm ,.. j he proporn.m-..b' It df'IOI1ldon i'1)ftllof"l1t And NC'()J(nl7.ed.

P'rttl"Ubon ,_be. unmnlroDed :'1n ... or d'l'eharp M oJ, ....... " of uurmnl 1R'"itinn. Th14 PI"(>m.hlr1!('ocnhu..lSon ,.C'"ult",ln l,utCI!"lvo J)l't!JII8uruduri~ ,be """I porUuu of the M)n'lIII."..,lontlJ'Ote nIdi auALo.Jd,ut "b"utli\-e tanJ)e"Atufft.Ar.y ... .u.inod 0,",",'''. eOt briO{ porlud InlhiI condition tan re..ult In burned "IMt'HIr.,b1"Obu q-lInder head., .fCulfod ('..,vlind.... wells,and d:\JM,I' \.0 \'aI,et ."et .park-plusc ..

The 1)~ce ot prolltT1ltloncall luulllly benteOguil;\.-d,in the rockpfL by roughnflJlt', backruin.. and poMiblY by .. "uddtu incr('a~ In head~tun. It ia C':auMdby the P""",,",N ~ hhin\he comblatiou cha.mbw ot &Jl a.rea "'hkh f~in-candescent dU1'ing the COMpression llitruk. sndsen'PA "" a" hl'uitor in advance of TlOTtl'IIlI iKUi-ti.OJl. Dttonation can l'Ave the way tor pre ..ignition by proctodnll' an uocIod sure ... thatbecomeo 1_01. ){0I1probably1-' depositS attUmulated on t.he chamber aurfnee5 Are

""'porlSiblo.

TilE AIK('ILU., l'()\n:KPI.Al'T THf: I'\"Dt:CTIO:\" SYSTEM-I. CAIU!lIKF.TION

proptr IDAinttnUlee and ~radD prooedQJ'ftatnuod at m&lnlAinlnJ: the combcJstion chamberin proper condition.

Ar. duu'l-'W tltmpenLu.res are r.l~ ~iLh 1lDitl

I'WA. 01. 100

and..o pN\Jd~ :he fut': 110'"apPJ"Opd.tt toacllpart trf t.... ~nainf.opttaUna 1"a.CWI'. 1" othuwONti'. the t,~1nwt*roAM' rut"Cu!n the (.rbufttorOrfll,.IJ""h:d '0 rt-s,lOr.d to Airflow In .U!th Wa1\11tn produce 1\ t'utll..~lr t'aU" rlOW\tr cur, ... 1m.Ilar \.1) fill. 9. which {" typ~c...l (or all ru\tun-w..... nlt ..fta'n dAlfly "..emb~J t.h., (uff-a.tr",do cut\-~ J ., dJacuNM

l'or l)ut-PUtofl"

poNtbie for this I;ype of operation. ttt~mir.:u~mUit be manmlJy Jeantd.

Non ....utcmatie u.:riJuretol'l an! u.ual17 ee-.lr1ctfld to the float l)'pe c:arburf'tOrs.

AI1'OMATIC CARDt:IIEn)U$

AUlom~ti,. f.J\rbure,ora hiNtpUna~. an auto..matte mixture control unit. ttn"U"e to pres-.1.1 ... and temperature. whk-h COCl'IIptn.. tH fM,.ha,.~", in both altitudp and ltmJ)enUurt. ThMe~.;\rburtto" meter ilJ.el 1ft audI a ... ,. AI to C'On~fllnn t4) tht- txuie tueHir ratioa&.r'\" tJu_It""'aU 8tth. eor.dit~ 4l"Id it ia ~lw:... rOAl \un,.",gr,. 10'''", t"'e porIiliOl1of th. mi:xt\1rt f'Otild",.:t 10mAlnt.ain the n"'.t'll'lually Itkctfd m:xlu,.,.

"IIII\'.'I'we mlu1ntdly eeteered euxture Nt!ln", ,,~

tltll.lI;r A\''\U"hloe-.~!ltom.tlC'Hi..!.- (T k"'('" untl (11,,,")

'1 " ..1... ",.11,.'-"In (Crulu)-Io pro,,:. mixhltl.:. 1i1\'lnS the .. ,..attat poe.tlble !\III:' eeee-only; IImilcd ~ "nriM pow.r and ~ n"(u"': and ~t-r.alI)' penn_able unty undert.,urab. condiUoni of J'IO'I"r IU'lti t'OO4ln

TIlt! carbUl"tlOr porromllin~ curu ,U\ tntl_o ul eeu\. ml.xtuJ"f If'!'t1l't", 1.1 tIIUMr&ttlll byF. II.

119. f - A Sett'ng C_,.... 'fH A"fom.fiC' C.,"""'.'

TIw "bow nW:tll.-rt. p(l$b0l'l cbo.t-,I.,. ....~1I lorn ~ 1ft,jIiIIIo II .t !lIn...'III.~~l t:I~ .... la.lld.vtd >7 ~"It 9tltiQeyA,.1'C:nft .'IId Ii other _lIUb.ch.fIr ,1)11 .,.. ",.ritw4 .-b .,....U'f ....ffl"'. (~d!Jn.. 0tJt,n dIwa~ _ .", ...t,Jliwr &.uUt~ildcfU$,. ~."., ~ ~ :. __ ~ton ll.aw -nch" e.I .....-- .,a...~ ~ :..:ad.......~ ridI-UI!-~~.'" illrwtlti-...,.,.,u.-- -,...,.

It. ,.. the usual prutice to litnit the uee of It: rautomatic bft MUng to POweR ~1() ... 61t:! ofNormal Rated _ ee.

ltOTe rec:enUr ~ At;ltom3tir pressure itlJtIngth C'Ompu.lhl4o to ,t'I, au~tk lean 6Clun.r of ot.h.rc.amlolI'Wwra. At hlp.,. pov.-~nthe tnl ..tu",u e rKh. 10 1[ht mlxtut'f" .tr..nrtlU C'Om.parabff to auUwMt\( rich.

2. IUC"b - Thi. pt'O\okSH minu~ 4;tron&tllltJf,rhtl)' ,Ich:r !.hun oormll1~ It JII u""d torall fCt"OUr4 OI)f11rAt:on, Ilnd when l'rJl~cllt..n"IU" w~"'jnr ffilUit'H n mlxtut"f riehor umn!ht nbt.ntn~1 whh uQrm.I, 111IIUIII)' IIIlLAuWl it.. I" the r'@fIuirt"dmintl'" eentrotpofll on for ulkc-o!f find 011.1 KJ)PU)lh'h

Autnmatir- f ...hu,...t.ol'~ mAy be of ,ith4:I' lh"ft.,.t ur HlJl-'\:lJUIJ'>pea.

On... 1>0 , ... h........ meI

PIIA'rT ~ "'H ITNE\' "IR':KAFf

r..P1FA. OL 100

1~)NTnOI.'

Thf (u1".etlonlr.a of the carbu..notor it. J"eg"Qlat.edby two 40.'08\'0":

1. )1a"uliIl ",h'.r. C'... troJ "'~H.This c:on:rol.sthe fud nowand ., r~ta the iwel-air-... Uo 01\ ron ....ut..)Cli.ouieenrbUn!lorL On ~.tOTl"lAlir 'r.WI\in order to l!.ii-I!t,in thf\ e.."lrol of induLlJon fI:)'!l.tt'rnL'ol\dition~.rod the ''fIgulftlKMt of fupl ftow. "\ose :",,:

I, f:.. ..hl&fttor Mr T..mpm-ahu'tt (;ti4l61-'l'hfotAlb"n ..wr Ail' tf'mJ~ratu~ S(Wg:\! Is U!Ulllly Ill..\ath\-c! in !....air KOOJ'Ielbow imm4!'dhl~l)' up-",,"m (nua the ('arburdor ent rance, AI the'''''I,.''lrt mNlMIn.od a, .hi .. lueation if. uiem...~ n-I .alll. rooMt" Dfdetuminina- see (0"""tVon. condJuonll It a_ pro\ Id.. the rt&dina o(,,~.tt'\ol,tl..uhb fur ~nnJninK the u.-rnpera-tu"" to!)!rJllKtl1 of tit. air for the purpcl' pC...,..U c:wkulM on. 'nl\: tIomptrloftA 1'ntAMIrt4lit po I t, ,,. the Irdtlon 116ttm t...(.\\eI!n ~....t:ft.l'tmr.{.,r ..ltd tM 1ntaLkCpo"- do noc: rtro~~de (L,""u,h''''' I":'A'.:" ofm,.uunng tem~rillurfll\nd., dn e,ot, pro\~. t,,4i,blp mlro'yn"of dflh:rminJr.1f dUllltO dtn.I1..)', By ullbrotlng tlLltlllt fltt'"rormA'U~","""ft \'IIrhI.LlOI\ h, ~h(l lcmflerAt\u"Oof thf; air ''!WAf-ured w.l the c:.rburet.or tHiLt'rUlr~Ihf eft'",.., of t1ur H'f'III1101~ ill tetnpcrtl{ur41 uLIhlti polr.l. can 1>0 "C'Cull~~I)'d~\(:rTOined.

AIl('fllpU. hl\\'. \K.~n 1rllu!u L~n'U!A!tul'Olh.e run-diliun of 1M ...-h(\l'!tfl ..ut al point.1I-betweeu thoc:ot"bunotUl ""d tho int.akfl pt,Irt bu~ til..,}' h..fHlnot JlI'O\'fCI f"""w~,IU. .tA"'~l"69dings of.ll fuel... r n-;a'llu,,' (Annot W obtained iJi t.he widely\an th6 r... of mixture ltTP-ugll .. tJlat &J"Cot!.

2. "wi n....\1"c:Tt ..Vel t\o\T" me".en. are~ pr'O'Vuled ('In I~ 3irt'n.C\ in orderto l>TM Id. a c.IoM ctAck 1111the rat1! of fuel ron-.umod

3. F......a.Ur Au..11 ... r: On f-Otne iMVllLat.ioU!.p.arbeularO- ~ IlMn" non-.u\o.rn.~tic t&rbure4tt)nI Cucl-l\.lr an.d"en. 11ft Ule onl.)' meaus otdl.....e~inil1.lfwhet'htr of not mixture $trenl[th i~\\1thin the pl'Op!!r range, This inFOtnllMllt d~tenninal tJ\. fuel'Air ralX> by ~IUl1plillg the exhfUist p.M.....

THE AIRCRAFT POWERPLAN'I' THE L,(Dl:t'TIOX SYSTEM_t. Sl:P':RCHARCINC

2. SUPERCHARGING

POWER AND MASS AIIlPLOW cinv1n.r the a.eeeuontl; while SOme of It i.. ab-_ in dririna .,.rclwvi .. .,...h i.m.What remains u-eful power .v.nablfl at theproptUe.r abaft i, lmown I:t~brake hor'f'J')Ower.(bhp). In other words: Ihp - bhJ) ! power10lltl. 1r'.ltSmur.bIlA tl'l .. nower ]O$w. lire func,tioa.t of bMh rpm. ud PO"'e.r. bhp bean no !xedl't'Ja"'Oft to J'PJn car tOo In.I._ .il1\oW. Althoughbhp I. _ 5Ui

TH& ESCI:"E AS AN AIR rUMP

n" ~"'llr d.vtlJoped In the qU.Ddtrra of an~4I t.. known a. the IndJcattd horwpower"hpl. S.I aU 0111 ill doll tAl Ihe prvpolluabaft. ....1 boI _ 0111Mhp t.lntlt 1n 0\--e.1"WI'n~1lI'lntMnal friction and In

Alr~ or ~ IItr'(\.I), 'l)UlcJng, the (lxy&,en intho .dr. i..by \'Orumo And by \\'C!leht tho mostImportant part (If tht combu.tlbl. mixture.Rou.h)\, 18 ~ of &ir, 01'2.6 puuodll nt oxy.&en. art COOiWDItd lis Lh. rombutltion of 1 peNnel01 p>Ollne at "b." powe.." mb

PRAtT lit WIll~Y AIR('RAFT PWA. 01. 100

llnEl:e lhe 1'QCkit. "'bicb to bf. KJt~l4,nmmust (:aM',.. both in~~1'\.i!joi'nt&.thf" COOYfltticma&J.h'('I'nft CUl'J':f'1IclIlly nne IClW','ectienl In it...t.anlt.!"lid tl,e .. t~rouV"hthe o~ht'f'.'l'ne Internal CIJ(nb05tlOn engino fna,.. aecord-

fngl~', bu thoughL or 1i!>)ln "Ir pump, wt:Q:ffo (If'.r-form"' .... de~nd. in laJ'!~fTM'alO'Jlrton iutapK-tty. Hl\lt o( ee.ch po1IRr('yC'iP i::t devroted to pum~hll! .lil'. At. lhC plJl\ton dt Ute jJldcm. to the c.~r,., ot the rumprt_kInand ~ur f'tro:CIo." ':"two cna-:rw ta ...... nm" out(rom pumpin, to proc.bc" .1\0000,hpotrrf't to keepItl'teJ~lIolna Ami deJiwr ... rCAJ~n.ab!ebalal'lol~ .ttM pro....:.. , .hat:.

MANII'OI.D I'nt:SS1,;Rt:

The "'flrht of aUt ('()n.NIft)l>(t by an er:a1.ne ...l.I~ndilIlrtma.tfl>'00 ,..,. tutaJ pi.ton di...,mcnt, the rpm, the tf!mlNflltul''' or the c:hkl',...and tht Jjr,,'NUfO txJ.l!tinx.t. t~ jJJt,akf' potu. Iftbll: L..", CJf tt".. 'tdon i. {ncrn..pd I'rW6l.tr4,unntity of air 1.8 ton:c:d tnte th~ cylir.dt'-n. .od.KI lone u t.be (u~l ....Ir ratlo and uLhe.r1.r:tC>rlremain cvnuant. the IftUlt i.a to (naa..M thewvight ur the ChilfP, !;mr. Uat- tnf"l1 N'1H.tedby ccmbustfcn I. in tu m PNPOrtional to theweight ot the C.Mr"IlC.it foUowa thAt mtake portJ)rel'lfiUl'U II. an jmpon~nt Indu of poww "hep..Iwer the oth~1"tatlvrtl aN' knowl~,

In J}.t&Cti('e thl. preau~ ... not :'DU.IoIlI'td atAn intake port, but at. the rim n( ~ IUper-c.harger cOllector. U is known ~. manilold pre&-.U~or .b..Qute blower rim P"'f'tU\U't" (abrp).fir even manilo!d ab::Jolutt Pn!'JI!SW't'(map), and1&e-:c:pr(!~Hedin h~ch~ nf mertur-y (i~.I[t.).

34

It .. .aD abldu~ "".l!Ul"oe. nu,'aJUrerd from Iterop!l1 .,.11n4)\ " ..~ " 01" d~lIera:tiaJ pressure,~'AUred from ~m., reference point, such I\lI.t..rnOIfphtri~ Vn."2>MJN.

Any ftt1&uon or rt.i1trie:kt:.of airtluw atrt:dalM preaaul'\' IIi thc colleeeer tJtr1, MnulCold I)fl.lal:$.UN 'Jt. u,,:terO-re. n.''lfUbt4'd eh:efly U)' the ear-buf"rim throWf uh'f'. ~v()dar:l.), It f. COlitl'\llltd by the Ift"~.t.I,.whleh ~xillh' lit th~ ('11.1'

"",,\.or tUlrar.e@ MJthe ......ull, of altitude, rnm,Of lhe ~rarJoa ulan .uxmar), ~r comprv.. oroc ... ponha .:IIau!r.'" It oll.uld be noted, J. not

poww. but nx.rcb tGQ\tDhmt Index (or mta.unr>.@:cee nt the: H\'f!f.l facto,. afTott n.. power.It I. on;), In t'Omhlna\Jun with rpm, uud uflf,rmaki,.. r..u.iA ~) CftM'OCUon'for urlJu-rwtur a:Jr t..',mpentul'\'. that manJJoId pn.'hU1'f:ma, be u ....d in ma.lclHI! An RI;pro.xlmlite deLo ....mlD1tlfmof bhp h)' nd~n,.. \.0 Lhe aA')ropriltte.OJ'M'f'W,tul.p' turns.

CAK14URETOK AIR T&lIPERA1'UUEno )I"'" AJRI'LOWAo...vt_.-tor ? hkh c:htlllK"" the m""" (It the

lutoJ..&ir ('ha.tJe wiU a8't.. the ~"e:'5 poweroutwt. Tn.. ejfcrtJ: lit variaUo.DI 1n manltoklprusure h.....e been JlotE'd,Anothf'r Importantactor is the temP"t"&t.ureof the charp. SJnoet.h.( .-eight of a sivl v-olumo of the fdcl .. Srnux-wre at a li~ pre$$ur'ttI.inver~ly proPOr-tional to its abso)utt Wnper.Lu.rc (abll. t~m)),=F + 459 or C _.._!73). it lol.,ows that &.Ii..)' '"_Cf"fUe jn tt:.e tem'Of-rat-ure04 tbe charge at u.p\,(:oG manifold prP:MltI,lrC ~lIult.ln a decrease III

THE AIRCRAFT P()WERPLA:>"l' THE INDUCTION SYsTE)I-!. SUPEnCUAIWIXG

itA deNi')" And 'W,","ht. and hfonce In d~.&rDC)QDtof tntfICY .val"~ 'rom ita tombuttlGn.

In pnctlu Il1o \tml>ORlw'o of Il1o r... ..n-tlwp I",," 10not m_orod. l.. t.o4, the t..perat.u.,.. of th~ ch.rre air t. taken all U._. about.to ollter th. carburtlOr prior Lo the (nJdon oftho tUIJI:.nd, tn eJlt~blilh1nr ut. carbu,.,or airttmperatuJ'V Umlt ... Allowance la made for thecoolilllr .ft'oct 01 f.. 1.aporiutloa. fo. Ill. heatriMdue to comP""~ IIItM .UpeRharctl'. andfor o\.lwr l.4lmperature ~ cecumnc bea, .. eee \hI urburtt.(ll' an4 th4l1nt.akt pl~.

H i.rhurbu riltor air tempera Lu.... are u.nt.IQir ble, not only b,c.UI~e th~y reault In .. Ion ofpower, but IlloOOOCAu.&ethey may Iud to deto-natton and conll4lquent enaine ttalhU1t.Jt thusbecom_ one of the pri.nc;ipaJ furxUo,. of thelndUd50n '),It.em to debnr \.bt twt..&ir charpto the c),lindeft at the propel' ttm,ptftluft&.

th. wid. oJ)tn pualUnn. manllold prf"\lrt willbe fOUnd\0 dlcTftM altitude inc,....." o.nd\he ~prtIM1l)n or I.. ot powtr would be eon."mod br .. corqut:mwter. The l"i"uon f()r thll tato be round In L" .bUltr- or. be'lAIr. Inability- ot. the ,",Int w pump ~utncrC:J1Lair.

THE lJ~SUP.:RCIIARGED E:-'GIXE Aaaume. for H"mpto, that an OJ)fUIl df'lfvcfI600 bhp at IOIi I.vel And. to produco thl41power,toIl.I.umes in one hour 43,000 CLt tt. o! .Jr wei.rh-In. iI.'IOOIb.t_If ve1. At an aUitud. or 10.000{t.. ~OOO ttl ft ~r .,.lgh. 2..460 Ib tl.Ddat 19,000It weish. """ UIO Ib SinOW" outputhI the ~ c:ltpencl.l on ita &bllit)' t.o oonlumepo" rather than C'ubitfeet or air, it follow.that the IKJ"'"l!.r,,m dec~a.~ with altitude much Iho"'n in Fll'. 13.

'The relation between alli~ude. "'tbrhe, androIume ca:!l be illUllt.ntfd in anothf:r WIY, AtON level. the 3.300 lb .1 air ....... ,. 43.000 eu n

U the lUt!l~.lrell.rae hi (Ofted ~ntoebe tyliD-deN! admpl by the prtaW't uu'ed by the .~motphen. the t.nain.e lit c:aIled 'na tun.1lY upi-rated" Or .......... rd>araed __ (-AtpU'&~-me&na to draw by 14lt'tiorI.) Such III lndudloll.ystem sati.tAt:1 the reqQit"t'.menli of moderateperformanoe at low aJliuxle:e. Prima.., trainlnplanes are oCt"., equipped with luch tnglON,

Rowen", once thl. type 0{ en,cint hu left the.round ita UmltadOC\$ beeome aPPI-reeL If the'rpm ia MId _tIIIt "'"' the Ihn>tut axed in

35

PKATT " WHI1"NEY AlKC:RAFT PWA. 01. 100

rNCREASING THE PU1IPIXG CAPACIt'Y__ bout the abe of \l"o-Itorr buildJ:n.r. .Ai.

lMjlO ft IlIli m. w.IRht .. ill octllJlY 58...000eu 11.-",hl('h wtll recutre an ~rtr&M(Jl'yon the

~ulhllng At 10.000It I~will _.py 78.000eun_ lind thu or1a1n.. ' Lwo.~(or)' buHdinr i.nn ..three aUld(,,,ull-h~tt lII\.(Iri hlrh.

36

Tbt JW'Obttna01. deti,mng an en.ri~ ,hat. win,..rnuhl 1\.1po.;er output .t altitude thus ....5Ol'\~ illoelf intoo ooe of intTe&ai_ the engine"*-(r-flO"","",c&,*u:y. Three di1f~nt methodsmay be ~ to accompU,h l.his:

I. 1_,....,. plMon .li",llItf';mf'nL hy .ddjnr orc:nlaml'rc,bndenl. Th[" i" a eumbersome mclhad t.w. h Intl"NI'e" the ..itc of the engine wjth.out. InueI"in. tbe rRtJo of power to weight.2. I"i:1'taa.e rpnt. '11\i. fl!is(,8 the pumpinA' l"At.eof lh" ~nrh\f'. but olTcl'ltonly !I pHrtinl R(liutiurtto U\fiI problt!m .,. rflnt.r1tukoJ rmd JleciprotAtina:tOfUlll .~b' tmJM).t!tAlimitrng &peed.3. ~Vpt'rt'Ur'l"fIby incvrpontfnr In tho ~lllline JpI.'Cial .lr PU"'P .. hOl'eprimary function J. toCCln\PftI'o.. more' ..~lthl o( ,ut into tne fixed ,,0) _ of u.. handlod b, Ill. pllt... nit II ti\.n::wthod~t commonly u.ecllO raI~.n tndnv"air pl.lmJM.r.1 faJlM'it)'. 'I~ it ~ for no inC'T'aJioe JD I11fft CW' .. r POWf'r Mt'tkln .su. and addi,...t1\'''" hlU-= to tMovcraU wti ..ht or the pow.tflI"nl

TlIII SlrER{'IIARGER

TM COD\~ulion.J ,.uptrth"-"aer Ie .. c4!oLrUu..I'll air comprv",or f)IACed b\rt.woon the carburelOr and tht '1101\(0 ptptll. It J. usually houledbet.wl"ftn tb. po1IIt'lr and 8t(:CIIIIOr)' reAr IItlctJun Ita prlndl.1 (elItUft". whlth .rc shown on ,. :~7,NntJ ..t of thn'C nu,tl1 unIts:I. .",,._lIt1'. A1t..orlNWiul{ U,e co-rl)uretur, ~beafr pl. .... tbrough t.bv su,perch.rl!cl' throat toth.lmJl'l.n~r. -n.. ttrll)f'lI..r Sa driven at roughly, to 14 ~im('.Cftnkflh.tt.speM, and lM..'C"u~ofIta hlah rutAUonaIIf)ef'd impart.t.a "rae vtdod-t7 tDtI'IY to lhe Nr,2 Dill-.-, ,.. u.. r....... oIuorlre leo .... theimpellf'r it ~ into the mfl'UM'T, The vane.6f th.. diKIolaeT -....art .. 'Imootb Aow while aI-LnwinK tht (~ to !IIOW' down as it mcn'cs out-nJ'd, WlLb ttwoNM&llthat the Yclocity~urea.cquind (w.m tho Impeller 1& rransfcrmed (nto.t.a ue PN"-t..u. ....3. Collettor. Aw leAving the di.ffu.'Iet'". the(harte ilt "\.(~ momE!ublrily and equalized intht Cf)llt.oT. wbeaee Jt is drawn W the cyUndctsthrowrh the Int.ah pipe5. It is at the. colleetcrrim t-hat nutni(old pre'J.ure is '-KKen.

LCCLt:cc

THE AIRCRAFT P

PRA1T " WHIT~J;Y AIRCRAM' PWA. OL 100

rpm and manifold pn~ Ibe ...... r ._bodby thu- au..-:n:h3T1er will be kept tft m.fnimWDb)' ()~ratfl'i" in the $owut. ptltf::I.ib&e impeUtr ItafraLlu UUI\ \\jU provide the df-tired ~n. pt.rtOmla"(t.

It the......molo bOll! .turdily er:ough to absorb~ addiliCCd ul whjclJlhf imptllvr rna)' be driven.

.%1 "Tl'O .. SlrpEIlCliAHGING

'.- -~)ljl'( 1101'_

Thu II~rtorm ....n

To "&4 i::cn....sed pcrforrna.na! fr .a thetGSEuw ptVvlou.ly used as an i'umph". a h ahnn.paClt-,. MI(Xoft't:artrer iR: irurt.alkril in plau ofthe eee ",h;ch pNwidM the "ground hooAt ...1Mim()e1ler ()f !h~new 1Oupereharg(>Thail a hll~rUp .pl"Cd, .nd It!. liu,ul11-ed tn Op.l'1"At4':JU"l "ahthe dcumatlon !fmrtA inlposprt llY th .. tl'm),l(:raat.u.nt rrH. It lmllpllfl'''' t hp. ey1inrlf:l' PUnl1)it'l5f UPIit)' of '3.IIUO C'Uf~Pf"r hour with 1~i.'l'll .J t-ot 66.01'1) 1,;'" h (..1 utr per hour. At ......tIS.OUO eu I:' fit aIr .. 111 .... :gh 6,500 Ib. andOle (IOIrpr pr t,. ,tlnU,. uv .il&.bJe at the c:T&nk.hw.!t. {.... In D&".:lctinv !riction OIM'II Yo1Dbr~ from 700 :0 I~OOOhn,.....powt>r Tbeh htt (".""",It) iJupctk'f". bc",~..r ~rba !

:2 PVllltrA~tbed by lb. SQ,..rt",,..r;.AI1>"""1ou,ty .!I! ...-d. lhr J.lO".rrr~ul"'" todt.-hvu _ (II''''' wtl.Jht of Alt .._tift .PPN"U"fNll"'1 .. tn.e w\Ure 01 the ImptlWr"', t1P..p:..-d... C4.>ftC!elvab1:r, In ~ml"'lIf'r ~ cvullSbe J"'Nth4.~ &W'-t ",h.th .It .",uld no Irm.. ,I,.. 1"11t("l.nt to dri'if! the il1\.-kr lIrcau_ ofthl t.rJU,'c~..,h"c Itartion of tM ,n"JWI fI(I"'.:r. hl'lllrh"llJy Ltl(l..u~rdlarJNr, Uu vee, theIImlhlLJollt' ImlKJ'll4!dtw t.,mPf'MtU~ n'4J wil!110ftrvon1 th" J)OWe,'thero pou.nliw.tly aVllIJltbl@.

I'RAT!' & WIIITN&Y AIRCRA}'T

rI'WA. 01. 100

SUPERClIAIlGIXC: LIMIT ATIOXI\

A muxtmum ot !l()CIbhll iii only pot~nliaU,.Iwallllblc, however, at the pl'IJp(!Uer.hun. Howmuch of !hilJ l)Otclltial power een &elually be\nled may b4' dc~armin1. it thoetnri1~ i" t~lkonto nlUhHlft, {l.nd 1\ vety arnduul d('m:ctlt tKtkunfrum 26.U~JO (t fit: 1ull throttle Md m.'tXSmumpermfillAilJI(! rpm. 'rhv dO$oOOnl II ("'UIIUl"'A!J~tlSJU.l{87 ()ttlHt~ (u\ll-I.@o., n fUf!JQf re!l.\thely tow:'IIHI.knoel< VOluo. A.!:Ic.ltltufJe j~,k:c:n:ulh...d thtl)fl)"I"lll"e lU'Id tftmperatUre of the chArae "rr in.I,:rl.!~.!I(:.until tiL IU.U()(1 re they rv.ll.th the criticalvl)luO& fot' this Otll'ti

cr:

LC

Tit!: AlRCRM'T POWERPLA.''T THE I~Ul (TI().\" Sl'S'TEM-2. SCPERCUARCIM;

bh,) of iSS, the .-~ and :em('oeC"a"'''' nt' thecharaf bl":enmE"C'ritital tor Ute IOU u.n. rue~.t,d I.k;lll.tLaLlonaptn bFa-:~. With HUll t;X'1 tbe-I)()Wftr 1')1lt)'J'Jt must be .inuted to 6.l!i hhp, ,nd isuvwJtlollJJeJI.t p:lrt th~Ue. trom ..:a .v\--:) to10.000 It, the erlrica. aJUtud ..Th6 selector vnlve is new IWikhtd tu third

cunk t'(mtllinitl$( to mUKJC. Clund~ton.l.nr fuel,And thtt fI!''MInt raeor:Hnu-.-d ~rOft.With thbit.fl, df'tcnunion i:l no I()n~ .. Ihv limit ..... r.c:(..uT.~1:\lcrlh~k:.::I""II': .1.000!t tM,. ,. an uat)" nnl.kand tt:~tr.alnf! (a.il~1IS .1 sa drr"'~'op'n, N "hp.fncbt.aU,.. m.t th~ )iOUl Clot ,u .trutlura1.' ... nQ"th h", ~n J'H,('hM. '1l:Lt. t~JttI.~ tal:m~'mum a\,.n..ble bbp ftprdLna et fUN qual.)~y, IHul 11,0011ft i4 the currt'llpomllr, "uIl1hmt~tltt. or rritlfal. altitude. "'''hilt. tbu on.r.uilC...Ndlit 700 bhr. 61'\ adtliri

...._"nux-nET'if, " - ,.tt.,,"alt'. C.mpoli .... - Un.",.fcho.t,.d, 0,...,,,4 ...... ct

."d .."huM $f#petd.al~ '".,,, ..

PRATt' 4 WHITNEY AlRCRAFT

'I~httr..IIt...ll dOli plueed I,)J) maxlmutn PO'tlltt wi-f1ut. by .trurtur~t hmiunionJr. .hould not bt'intnprrlMd .. ~ r~Ik'

ahead at, ur "up-stream" Jrcm, the cnrbumwj. lIIounllyfurnl.lt~..t1I) th~ .Ireran nmnutac;-turee (II dblinct from tM eJ:l.flJ.~ e "nura('-turer). WbUt' not "pan oi the f"",lOf' hill .f ma-teria", thlt d\l('"Ur" is ali. imuo.a.t.. J)C.If1.IOO lhe indUC'Uon .>.ltm IU'Ii fl-Xf'1'U rorutdt:nbJ.tinftu.~ un '"KiM perlonn..,.". altd t)w nun't.tn4n('. Or pro,,*" i.lPCfttin. ~ndiuon ...

'I"h :n:r...t:l dudi".- alfKts euloe opil!'MtW'lf1lUI l(,)lIow#I:!lAM

BfI("nul'Cor the IUCWHC"d motton of tJw. aircrtlll.cunKidCl1ll..1lu\'~ll.lcity flnel'gy is U\"U.. lJk lr' 'he1dr ontf.rI'g the t:a.rbu.rc\{lr air tntalu~ PrOpdformltlicJU v!' thfLa'1' entrance alJd the t*t"'A,"and f'!lhowl' or Ull' ilU' ducl. ca~. resujt in lbe "...OO\el') of .. Large po.r:io:l oJ thi" tMf1'1. Orram. and a;.r will bt fu.mi3bed "to the ea.~Otat " PN-NVrt f'Nter than that ot the attuude

42

[

PWA. OL 100

MefMNty ur ... Ie t.u U~ at or nt':1r ~ Itlvtsl hi()rotr to mMiI ,he ,,"'.~~r VUn\plnl" ~Qull'e.ment.at U.e bfJrtt4," Mh.,ludH. SlnM tht dan,..r r.e..that ,h ral.u.l mM) lnad~tr .end)" IT u..of ~hlJiu:~u JNWIW ., Je,,,, .t,:t.udtf. r.y .xuedI",. ..... te limit'". manl~oId p~.ll b ..... n-tiaJ ttu.L h xt'n:'.1Mf btllh eaee and :ud.rmenl. t4PR~t the t'11K!c ",,!nIt fh. I'\!I!I:.IJuur ur.lt\....ftUided ('IperatiMl,

DUC'T1SG_I "\l,'hlth lb" lun'n.cl h lJyiuN.. 'l'h{& tillS, thOdfecl 0' hW;ON".a,"lrrU,. ,:.aptreutgJng tllp.cit)'MIld. If: t!:xln.'n"'1II!huu.uooa,. hi"b \!0I"DH!d., Ute llIJ.cl.lCUl to the carbu~tor i~al'Tf.Da;ed eo thAt.th~ r-.m .air can be eloaed ott.and heated, or mo.lduA--ftt. v ak drawn in [!'\1m 1\ilel"(::tll &O:JJ't.'O. The deogree of heat requireddiffer& hftt\'t'E'n fI:"(fine MOIJ.-I!' because uf diJTuJ'...~ i!: U:.. rr.tthud ot jn.it.'t'tiLljl the fueL.

The tnat~ ..t. preholt C8PAdty mUlIt be {U,....!"l.iahP.dfor iM...,aI Ht~...()f englrw. in which lhtrut: :. utitr..rd 1tn..-u.'Cti.&td_" d01lo"Mtn-.:-m fromtoe' (;lrh":;rrtUor. In ~h.,.,. cues the l..d evapora_tion OttW"S i:tt a rtpCIID lo ~itit.h DO heat is re-

nTH I: \IRCRAFT I'OWRPU:o. T

-- -- ....,.._, ..........", ..........-.t ,~--_,.-.........

HWtt.t (romoth~r IOUR('lt und lht &fm~,.tu,.or HII' eh.rae ls lo"~f'f'd a. murh &0 F(2" l') wltl'\ th~ retllJlt thAt lh. rnol'tun: eee-la'n~1 in the C.hl\r'tCfOwill trvt2u on flU)' con.wenlt'IIt, .utrate And l)OMlbI,. blod, thfJ Jrf'f th.. rarbumor .Ir te.mperalure i, bet nIII F .. OF (0 C.2~C)."",.n thf" tut.J tl tn;.tted ImmltUatdr .d-

;a...t to the reee of the Smpellor_ In. IIW'trature drop put thl t~U e,All uJ,K:rJ\1.tU:1oI accumulated to dMt.: CIOC;du:ai\~lydItntonatratel that ample flrfh8t capattt)' ,~u.. emir IU,.. method of pTO\idln. tb.t tIm.-pent"fW .-- Deeded W feftkr\;. k. alre$4.rfOl"lMd 'I'k ~Ued "a1t.rnat.. ....r ,,.t._"lAklrta &If from oyer \be CylDdt,.. or trom tM~ compartTn@nt doN no( prod. ,uf.6d.nt tempe... ture d. to C'n tbis ~Ualprotection.

tann4)'afk"e. II. 1, .uiUUJ aOUfCCor trouble toan c-n"r.t, Dun rond""t of IIMAII J'l8rtlelfll n(haM "bru!\lf; mllt.f'l"l"l,T.kl'n In by the wlr,It tan cutloc," un the rncterfne Illeme.nt8 of !hI'!C'arburfotor.up~Un" th. prop~r rei. Utili ur(~J00.' tu vu",,\.r. It. nO)l\. Ae'1J~rh h"~lfIn ~h#lt1hndtl' w..n. by I"fndlnr down th .."... u. tllW(1tand tbt ,"""ton rlnx Jt then e(l('It.mllu,tJo~ tl1"oil .1M til t'fI!rrk!td .h~.h the "'I'ln. ('au.ln,y.,. ~"na:'ahd cu.n to 6.pcrit~:~d... ~'I'!I.C''nft"'nt' e.... 111M wtum\liadon may do. anOil ...... ,. and fAUM Dil atuvalaou.

WbuN. tlUIl Jot mu&l evident dote to ,h~around. fn C'f'rtAinparu of the wortd It (':tn h~c::a.m@d u, allttud., .." hbrh " lI5,()UO fe.t. e'en-tlnu\.'

PR,\T'I' & WHITXEY ,\lReMIT PWA. 01. lOll

The Mtldo""y .r u,~AI"" deJWndo .panproper m.lnt4!n.a.Dc'e and lUVic:oS'. Pt:r;cwhe re-moval fin,l denning or lher"It~ e~mer..u it&:c.s;ientiill to lI.:l.tistactory f!ngiJl(" prot'ldiun.

1.fOlil prndll('tioJl Ai'rtl'.rl tor e:viUw.n UM donot inthlCl. filren .., .t.ndard eq'lll~mcnt.WhPre tt:-. Up".r;uinm: are cor.d:..adtd trvcxa .....11-...!!tabli$h~1'hl~trn'e bit .., the O'!'fti~i(Jn of theflltcrh1a "'>'''tcm ts jUJlitlrl4.ldin order to f!Um~uatethe nllvr(oell\hl~ w(.'jAM lind corupl!('atlon ot lhl.'in_slnllot!on.

In l~ taJk.'S wt. .... tbe aift'nltt. if tiu-Id8hf'tl whh .. dlw:el'and 1\ " pM!:IbI~ to _ltd:p,lth~r nun or ti~tcrcd "Ir, tho ram P'*IUon fapl'ofun'fld rflr ull du~t.trfl" condition, 4)( n~m-tlcn "'''' the m\(~ring.)'.lam UWe.! rr.awra~u )QU M 1'l'Im f"r.A.'I'X). in tM air au ""1 ":0th~cn"!",,.

!\Cm:~:NrrtlH & Whltntw AI"'natt. furn'.bOA. with

tilth \"1'1,,1"1\,It l..'OI.r. mul- ~ III be I'_'

44

.~led twt .... ~n the t"Jtt'bur.1or M.Dd tM Itdja..-('tnt port~ of the a;Jl'fTAft ~afr dud.T'h.U ~I't'fn t~lor tbe ef'N))Llru J)O~ of pre-''tnting ~onl"" nota, bolt fl3.per$, rAIlJiI.tonl$0' any other k>Me objOC\from furt;hflr pone-tratlu,t lJ'It !ndlK'tiOd lQ.. wm And eamliJ,::nA' thE'i.m.pelIet'. It&.Q,Jo" opf'.I"2t.on. hit\",. ftJDO'Io'f4 thel"OM!'I'OCfIIt in ordw to displ)'llf' nf a IIB..~ ,\lrfbOCtor see (ormlA-tlOin. W'hfle they WE:re "~(;1,:1:'5futfrom this JWtint of vj~ their experienc.fI hltMbeen an unh,pp), one In that. the tno\'1to.bleatone pltkod up by a pt"(IIpi!l)U. or tho nut thatY"U 1..)1f"1'kIOM 1l"hrn th. air JOeOOP ""u' re-_ h.,.ed up tl>. lrr.f'OUcrand n4 0\... which thewhM.. IHUc, If IU'~)',eontf'nl. Pratt & 'VhhneyA irc.m1l. tot rotUrty 1"t'('()nunen d {\ th. L 1hnt,1lac.reen .. bt \1.1,." Int.!dcd,

rue .~IRCRAFT POWRPI.AYr 'I'li ICNITIOX SYSTE~ITHE IGNITION SYSTEM

I

III

r.\RTS Al\O f'l:NCTlONSThe chi.f IlaThl of I t),pal 'pat Ion I,at.-m

anel thtlr CunctJOJ'lll.re:I I'in,Jnetol~n~:rAtf!"A('umn' ut hhtb \'cd~

"fIt which i.!l dJ.1d....r.td "' the pro~rttme.

2 DI!'tlrlbulc~r:di..tributH lh. curnnt to~prwer ....... plO$.

3. H.mH!l! U'~lI1tmft. the (U""'t from thed"tribl,ltor to the p'q;t.

... Clpa_ .... PI..-: igm~ the tUfku (harp 1:1\thf' ('ylioden.

6. Shieictinc! PftWldl'a ~ndtd metallic:CUcl05Ul'f! for the tnlltt ignition .y.tem toprolOCL radio againl'lt jnL"'rttn:'ll~ fromthe ignition

PRA'I"I' ;, WI!I'rSEY A1RCRA}'T PWA, 01. 100

By operatin the enaine fit reduced power forn tew seconds. fir~t on one m.ag-neio.and then ontho ether, and notiug ib rpm \1rith the ignitionswitch in Lhc BOTH, LEFT, RIGHT nnd OFfpru:citions, it may bf. po~"ible'to lel"ft.lrnlttonand tead to )fad fouling: on thl\ ()th4.1t,th~y1TIOlrun 00 cold .. to b. fouled out by tho.COImutation q( unburned Cl\.rbon. Sparkplug troub~ 511Uke1y to b@ loc:.UlcJ ut cueor \'+1'&1 pIUKl. but. I.b, t\'ldenc@fJ 01 sJ)arkplug trouble are much the 8:une &14thOM ofotb ... Ir .... o! .. nlLiort lm!gul ... ltlo.,The ooU,io.r out. oI ollo--hrut ot the iR'nition'Yftem. Ot' the failure of I) "pl)rk plug' in j)Mor more C'yiinder", wiJI f'e!;ult in R)OWQt c()m~bution in thoOt'!o'linder$ .ect.ed. The etf~c1is tolDt>Arab:e to th~t of delaying the timingof the spark diKhllrge, and tho C(lJlSUQ.UOtlcC'i.a 11 1O:tfof power. aJU\olli'h rpm llnd m~ni,Mfold pre..,_~ure will, Ill!. a rule, remain un~hanged. If both plugs rau iJl OUl: or mOl'e(,yUock:".~ lobe resuJt i.!.. e6f)entially~ an en~gine. of few-ef' cylinders. In WI}' eu&C, t.heattempt to recover Ute Jost power by in~creasing manifold pressure is unwisE'..,aincl!it lWly lead to detonation, e:!pcclally wbenoperating in the high power rAnge.

c

""';':Q~ ~~\.It f) ..."r..,... ~ \-0 ..o-.z..,.. ,_. ~,..... _ n.,.,..k ... !J;-J.kl

ft( erv.&> ')( l." )I.. to;. I.I~

f'"JtR. M NU

;X~~"'k"""

liP W~ ""'!!- ~ ~ I .lkcO ~5

-

POWER BMEP & RATINGS

"O'-ER, 8Jtll' A.W BATJ:\C!> ronR .~'D ITS MEASI.RF.\lF."iT

PART IIPOWER, B~IEP, A:\-n RATINGS

Since engine design and operntkm both haven. UUlir ultimAte objedi\c UUt ctflkltnl and!'tll"hle )'IfOdllCclon ot pewer, it mAl not. tAh~!lcther inappropri:ue at ,hl.J point to In.jt adonnltlon of .'po....... ~tho< with brit'd.... riptl~or the methodA by whkh It .. "......ul'td .... proc!u

PRA1T & WUITXEY AIRt.ttu'T PW'\.OJ.IIIO

POWER (WORK + 1'lUE)

Power may be "juice" or "lIOUp" to the la,)"-man. bUl to the ir.itiated. it. i.t thtl rate of dninl'work - in other "4)rds. tho QDWUllt.ot ""'''rkdoue in II certain lenl'\h of tim

Thut: Power - Work/Time

J{ the .-4., f'!f",_ 4 "~wM at" clot --'t .....- iA.. tbIt !'fOII~,.f tit. -..l~t b1 c.a.. ..-.J '-vM.tetA '1&.1n - wU1 toe t.bt ~ .f ,~ ret.~t..te.r.....Oa U. .t." if ..,... .. tn'Qu"ur. aIM.t,. .p die

F'QI'f'f"=20.000 IbD,.tnnc:v/Min ~ 2:t X radhy X "'"'

=2:()c. 3/l2 n X ~'OOO=8142it/minA I ( ) HP- t'!.lbp!rmln.III 1 - 88.000

~O.OOOIb X 3142 tl 190= ~.ooo"" t

Th, h.l,tJn" tOJ'c:eu.iltin ttl tMIbah as \herNult or "l)J)bttna the :W.()(I(I Ib load at the endo( t.M a in It-\ is kAO"'D U WI"qQt. rhc.who have hand-c nked autQmobU. Of' outboard mown u\". applied torquo by ntrtlDl"pul'h or pull at right an.lt!t. to. "".r atl.cUdt(J rotnUnr .halt And

Torque = Foree )( DllIItanr. - lboft.wht~ Ihu dlluUlce [, me.. ured in l pls~.. hlch It At n 1'lght analf to th" center nee ofth.. ,hkIL ~UJd_ th\! IVI~ i. tll .. rlat'" .n.~ tothf' dl,.tllnee.

ha the f.LU!l.P" C"tel aboT'r tlIe ton{ .... ~aaI I.1U.000 ,b >< .n 1\ .,. MOt .~ It ..,., "- fICIIkIIIt"', &010 IJt..t\ cl 1.o.nI" .w. .. otu,..... t! 1COO ib f_ _.. app.Md ... ~ t~.,. ...40.0t0 f~ ..,.....Ftti-i WItt. ... ..,.. N 1"...... n.. ~, tOlr'C.'ll .. tIw tM4 I. ___,~ u. pntodtlcl.r ... t~ c.... ~ ......,..,.,.,...,1" ..... --..'na.,dOff. l~ torque preltnt 1ftIhe .......n. ill

irllll.!QC11dentOf its dio\meter. It i, ~IISU'" of1f1*tJMud i.'t pJ'(Jpcrly. tt,ourh nt)l r:nJ'JIILrtantl,..f'x~rtjllJ!f'f1in lb-It, It is not to bo coofu-ed withwork whlch l$ eXPl'e!..~d in felb. IllII pos._-ibi@to hnvp torque (1h-it) withoot mOllon in wbkht~1.! JJ() wurk (ftlb) tR perlonntd.

Plunging beadlong inlo the mai.htTN.tiQ: nf bOl"k})Ower.~tion (1) ~ be ""orkedjill) that the usclul cnaine OUtput can be u-prtMoed 10 terntS of rpm and torque.

LI K rr rO"Q"CI' .r TOIfOUC. WOIfIf IN ONe AEVO(urtONnr I ~uc y ..Pili WOIII(III ONI ftllNt/"C

ttlb 1(I) Ill' -;, X !Ill.OOOXCiW torqUO r. dclln~ AS Ibtl And MI ('(HI

lain .. _ (OM nlue and also A dlltMCC valuf\,To oll... ln f't.lb/mln. Il hi nece ... ry 10 IRcludoI., bocA,*, of 'llttr P.l"eMDt In _"Iy rotatina.bat\. rtnrdI .. of the kind of power prcdue-in,r unh that iI C:."'.JD the MaIL torol.Le.TomN.aure .. "d c01ILrol Ute j)()W('.r d..livered hy th@thatt. it it on)y nec:e5!\.8ry to have mealnl (orrMQuri", IUtd eut.rolUnll rpm and torquf. 1'hftmon! dirtly WCI" two factors 8J,. m..a"ur~the Jlret.ter \h8 accuracy of the power dtkrminf'd.

The tachometer mea.~res rpm dirwuy. tn.tx.homcUr C'fCIIlftW is. geared to tht ('tank Abaft "," r traJ I) and the on11 i.naurades art'thOlllf 01 iD.ll.na.meDl calibration.

PRArr It WHITNEY AIRCRAFT l'WA.Ol.1oo

TorQ.ue hl\S been less accommodating and foryearN, there hM been no tamtible "handle bywhich to grasp lh[s qu.antity. It a din!cl torquemeal)uring instrument is not Pt'O,,Kii!d. mere is-then no direct eockph evidence oC Ute Jrituationand it ifl nec:e.~R:\ry to resert to indirect meansof meaauremcnt.

....1.... ,

9~";.'.,I

I .JI i',

t ",' ':t.~')~ , ,_.~

In tho In.bortltory, t.ol'(lliO ls ~\lrc:d by thedevlce "loUd~uublorb thtl enltln~'. power outpulTh ,II... t method employed wns lb. P....,ybr,,)ce which rQtul~L~ Lh+lt'Pm Md torque loadby m~anlln( J~ hrake or t'rlctjon doYico. Tho

50

fo~ ~ired to re!train the brake from turn-ing tould be me:a.s.ured and the power output cal-~Jlated. The Pron), brake has been renlaced byhydraulic: or electrical devices hut the pril1cirlh~1"tQU;in'the ume and the term, brake norse-pewee, refers to that part ot the engine's output1ha1 eanbe ~.asurcd by a brake.

A b....ke (-Amiotbe used for power measure-tnCnt. in flight sa the device abf.OrLI'Iall of tileuseful 4!naine ootput. Actually, the })l"(lpeller i$tilt bhlko ..nd tOt'quo could be calculated (l'OI11~idtration of blade Ch3l'ltcterlsticl providedthal blAdo an ..01e, air delUdt.y and ait'spood W(!NaCC'urately fV

POlIEII. BMEP "-'in RATINGS PO. Ell ",-0 ITS JlE..\Sl:RElINTtorque. The (act that. at CODllt.ant rpm. torQ'Oe .... -tlnuoua ada whi

PW 0\. 01. 100

lif_ 10- CVII,."., ,,. ....,., o.",Htt 'owe' Crt'.tut'\'e than with tho ab.tfAct nC)tjnnor ludi-uk

1b. nlaUvD,thlp bttWf'f'n hnf'p ..lid the ActualthA~ of lhfl p .......u.ro curve hAlt M+l' foet"l).liabcd bl e~~rlln~nt Af'CtII-dluly. it the Im rectenetc. ARtlJ, 1.iI\,,&Ui\t tolit", 'I\ll Ql'OOI'cprel'lf!ntlng' the jhP. thlM:

A"M AHCO Shooed Are (P ... I)l:ll!hllllcJ. Arta (C + E) - Ihp.'l'hf' mf-An, er a\~ra.Ke. pJ'easu.n (AD or 81)

,,1T~lh't during- the po'Jlrc.r s"TOke- i.~ n uthf' tndlCllted mtan eF.eclin p..... \olR (imtp).

The orwrato,. i:l. naturally mono C\locemKwith &dual shape and pa.k ptn$Uft of t!.e

~.-

---';g. 21_ c'(JiatN, .-,.... ," HOImcJ Olt~--lot

C\I.("\'LATlO:\OF DIEP

J( the- Indieated horsepn,.,."l' of a" tn.-ir~ il.knm\ n, it. imep can be com.P'tttd lrom !..lw!ft\nnuIA:( I)

792.U(j() X _Ihplmep (p.ii) - Uispltl(:f!mcnt f1)m

"11'"dcrhnttou of thh~rormula I. hri'~ ut U(JWJI:

Ttwt ''''", 11'1 ~ A U) oU.,..... .. \lw pNtNt 1 I Ln ,.i) by lle atU (1ft ......... !U. ,,,, kad u wh4d. t: aoru .,.

,. ,., ~ J:ow:.., 'r-IJ X 4 '-C- *" )n.. "'_. I'" 11fl tb~ _t..tch t.t. '.,'('w ......... "..t" .........~ drub as the JIr"", .1 U. ~n., \UI> i.Ud !lr I!" ...,.

U HI !Ii (In-In!

Tt. 1\, In t~lh.e,o:le curill,ll' .."-' ~ ..... , ..htll;.. it,hili.

WillI. (h.ll).) .. p y 0 blM'&J)( A )(' 3/12

It th. "~It\tl. h.1IJ.~ uU....k"-. ,'" ... ,to; ,..r

f.Y ,ikffl nl ,,.. .~ t.,""Itt\. .,.. A ')( a 'I( ~..'....,._-1:)(1

!It "- ,,1.. ..w ~ : antot ~ .., .......... at ........ "..u.r ......,,"*"t ThIs" "~t'''1. ,..~,$ra.. ,,' .....rt- II ,...I'f'(ooJt~''''''.", rt U. ,.lu .\t, ... , ... 1U'tI_ f~1u..... ,I'll' .l"~ .#..,-''''''''!'\,I, Aranll~l,.

W k hUll ). f'>l ..&;l'~I!VI' )14'1' rl'Y. -- :u

'1''' 1'11.>'" nnllu" (\1", ... , arid t~ (........" t"Cf'itl'""

'1'hi. would be- a ",-lWU".ol')' 'IUJ' of tClr':'iputin)t imc:p. a::d !i:&aapr~(htt:nj( .dual :!.l'oOmf'of t" t

In nH'rmmfne fnrf'rnal fri,.tion. some ,. dJ\"l'rtfICIto drh'Irl( \.hon~Ii ..)t"h"I>,such as the m",",lInia~d fuet pump . anmA i$ abROrbed in rlrhlnirthf. tuJ)e1"'Ch'tw,JnllL mcchaeism.

Tbt totlll J'W'I"'~"1hu, In"t b known M fn UI':O..... po\Hr' (fhp) Whal rerenlue in the (ormof UM;(ul pul'otr dtll\ered o:..tllkl. thf''' Iti eolb. (n"nPf'lI,., ~(t and oc:ht.. .batl. .. calledbn.\

=

P'i'A. 01.100

Thi~ ffl:\tiond\ip makes pos.sible a ~uft"j(~nUya,,:turalt lind nolalht:y 6imple (Of'RQUt.~101': ~fitip, tuld "UJli,~t~a aJ-..ort~ut to the tkltnnina.Hun or c),lindlolr pressUre$. Bhp ('.an ht ..._dU)(:n1c:ulll.t4ld"1 mt""11.'1 or ft Prurty braki." d.Ynamomele", (II' torquemeter. In (net. wh.nt'uthu t'I,IIII.IOIl between bhp, rpm, Rnd mnnf(oIdm'6MHI~ hM 1)('C'1lct\llh rr,\:ed for .. .:h'ftn t1~_'nt.the lilt", flUI.V lie Icund Irum a lJU"",'r,un". {(the III"t t\~O qu:trtitieJII I\t'f; knnwn and ltl..:prul)Cr ('o)"fL-'lllOf't. malic for en-btlW''"''r airt.f!'ltlJ'fl''''J'''' ,uxl other ite:ns.."'rich"n h~J)U\\ ('I' Utlp) t ... ()( a eorutant Ilulntity. bu,_it'l('rtJaM'a ""Ith the rpm .~ Ur.",JJtt .~ or"Iaa.: at 1'UP"n"Mrx\-s. It can .. d.ot.mun~few .:~y~vvn qm\ knd .$uptrtha.,..r.n ~hina--tion h~ m'.!..~III..nr. on;l modiMd dyutnlWnwI'(lII..-lIer "ntl ottu:!" 'lmn_ (Lhl'l. TtwHl'&t 1H ('AI11 rrlctiM mCM fltferti" .. pr~urf!(rmllp); 1110~(!c()ltd hi k:~()",,"n1.Iy the mo~ ftl-mlllnr, hut r.o 11":1111fonnfd:lble. nArn(l of hrllktmenu \.1(rcctl\e tm:uut'C (bmI'P).

srn('~ Ilflllhcr bhp or bmep uk e "ny .C'C"Ountof (ritHon. the cwJdm: can be tJlou.-lu 0'. Inths. f'flnnfllt"don. lUI a {rk.bon~ po .. er ph UlIn"hl,~till Ih._.r ru""Joc>od ~ u.. hln",withl" th. c:yli&dt:ra is deIJ"\""e.n-d .. ithou~ t4.aAlii bhp to lh.. pmpelk-r. SubN:!tutinl" hhp forhp, lJrn-t>pUllbt wmpulC!d b:r on eQUA(ioe. Idtn-UrAl In Corm And derivatil')l1 with th .. OM p.....\loU1Iy uloCd \0 (ompute imop. namtly'

)lm > (p.l) _ ;92.000 X blip0i5J)Jacement rpl1'\

and. If lldl'l btnE!JI formula he dh'idl'd b). lhe('(ll'tc&pondil1ll imtp fomu!a. it "'"iJl be Nlenthlll:

4JUIHP

Bmt-p.. lhI'N(UI"C. pro"",. to be ..omclhinK (Itan abIItrlllrUon - a &-tJlKluI prcUUJ'(!- \\'hJc11tau nu teal n.i..t4.'C~ rn U.. t"yli"'ck>t"R, Jm..,., IIIdNrt, If'''Mt#r than bm$. .int' it tumpri1k"bodt bmtp and tl'tW"p. (1""JW'ochng '''rxfty on1M rpm. Inrwp I1U\) be !rom 10 10 50 poi ....than iJncop. and fftIlr r"p~nl .u h~k .,. M'ot th~l&t~r.) F",rlM 1T'ore,th~ ..ctul fl"kP~"""'. &II> .... oYon nn tYhlldt'r pl'cs.su.t'e ('U.t\.Ct, an! in tu.rn ~n"\::ulc.:r I"An tho lm~p. N"e\erthE>IE'JlR.t.hUi abstratdor pro,.. to 1Jc II. u&efuJ (IN' in~Ij'"at;"j( tltt\ IId.lilt! ~/1'1!"!'ure!lar.d ;11c!tab-Jb:hjn~o~r~dn~thnits,

BlIEPA.'l) 1~1JF;~O~c;n.'J).:KPK5~lilL'i

To bevin .,!""hm~ mJU' be readily c.a.~:.rlated at any .!ou."\< of OpH'8titln ir. :e.nna ofthree quat'!ht.:._ th.t. ani' caW.O' found: bh"

rOWER. um;!' ANDUTlNGS

(from P'>"er eueve, tonauar..eter. Pronybr.h. or dyn:unOmtler) l"pDl tfrom .. tachom-eeer). acd _ f;OIYt.an\ (792.(1f""D:sp~eer':)tDt).l(ortOH!r bmff) bea-., & dcl'in.i\e rd&ti.o!::!hip tofmtp (bmep/inM!p btlp/ir.p) ... hj,eh it. f'Ctab-lIt.hedthroo~:. th. e.rIlVl'It'.i ()~':Jf4!' nlI,st'by rhe t..hbmthm of the !hp (ihp - ~,ptho), Sine. th au:tI C'Yli ..~t" pl'tUa..r-es ..,Jdother C'nmbu.~tlon (ht.l"1I.('tcrhLles ean be decfutoedIrurn ilU41P, tOO ,ir.ce tht TtbtioYl of lamel' \0imlilp I,. known, it rollo. 6 Uu,l these pt'eMU'"And other (;undltlun. un M d~ermined ftI"imp('lIn~ r.-:a" maR tha.. rn-ir.aJ ehaJ'J!t' l....:nJ)f'n ..tUnt a ... bf.inx rppr'OaIdu:.>d.

Propf'r ftJ)frahon de&rb' tics- .!IWJl(! .. "ht'n" bf..t .. -r. the two nu'e .."nf!A. 1..o"'K e~pct'iclK~uft JtlJ and Vf"'\ice operation pro\'" that 1hpf'''I f' an be 6Il(cb' operated with Kood d'Jnt,lMky J.tand.rdf- in the erujsinJ! range. ua.inJl'"fu'" at t-he J)fOt)Cr urlldc. for pro)ongE"d ppriorl ..,,5th UUJ cylinder pres.sUre!l anri t~mllerAtun.'dIn.-pruentf'd h31 th ...maximum et"Ulsebmcp jjnnt

PRil'''' & WHITNEY AJUCR,u,. PW..\. 01.100

where D = drag - IbC"= constant wbose

value dependsupon -air/oi) $~C-tfon and angle

p _ air dEm~ity

.'!peeUled b}' the engine manufacturer lor thepnrticulal" engilte TMdeJ in Question.

It must be emphaaized that cruise bmep limit.are merelr convenient numbers that describeoperutlng limltadons in terma t.h.a.t. can be ap-plied in \Jl~oockpit by means of availablie-to-tormmion. They do net define a kui!t!-edge lineon one Billeof which is ~afe operation whlle ontho other elde lmmedlete desrructlen will 00encountered. The tt\;lximnm limitin9.' (ruisehmep is cArofu!!y selected on the ba:t.Ls ct ex-perlence and teat tL'J the operatinR conditioncombininjt destrod pcrrormence whtle obl4inib@'long service lite. C()ntinu()u~ uae nf exees.,h'epower. rpm, or temperAtu~ will mere probablycause lmmedlutc dimcullJ;' than h1irh bmep.

USE OF I'ROI'Eu.ER FOR IXCIN Cm:CKOS "I""t: GK(lI:.\'11

In the ait, tho propollcr con\orb cnJrlIlCtOUtput, ln ~hoJerm o! rpm and to"lWe, into thru.t.Oil tht) ground, with no rorwnld moOdon, (bepropeller hna Iloth.inr 1.(1do b\lt..e.n~ M b.-die1,(1t'll~orb Whll.t#''''fl'" J'lt)Wf'1'"!.I'll! tmel"" bt I'rodl1r.lnR.whue the cmelcncy or pcrronnln .. Ihlofuuctlon I, (It 01) (outern, th. propeller eh......J\(:lflot'l"ti($ IlTe of vnluc bocnu,e LbCltorque ro-aulrcd to ubtaln ti gl\'.:n rSlm II pNKllet.bll ...IOtlr tI" the bltt(h!! anKle r" flxod.

On the ground, with Lhe propeller adjuattdtt) rull inrt'el\fted rpm, the blnd(llJ ott poelttonedAt {I deRnilc minimum anxl.." ThL8 .n,gle willlit! lhe same enrh t.ime thet.ttht prop.ellu controli~In thu. J)06ition. when the blades Atv in fh::edlew pitch. Lh~ engine ioll driving a Axed-pitchJllvpeller and the f(!laUonal'lip between entdneporfol'mance and propeller rpm gh'u Ngniftcent infm"l't'latiOll rtg:tr(linS( the c:onditiOD of theenglne. Thls cbara.etoruUc l.! uaod du.rlng theground cheek of the powerplant,

'l'he lo.ad pfQ\idcd bY' the propc)ler i, thel"e.illn of th~n!~i~Ut.il~or the air to the motionof the blttdes. If it i~ imrurlned th"t the toc.31air force a Mtlng fit OttC point On the bltde,the air force per blade multiplied br the-distancebetween the point of application and the pro-peller center Une times the number of bl:tdeseQut\15the tot'Que n.~orbcd by the propeller andequals the tot'que oUlput of the engine pmpeUer.h.ft.'rhe drag force ot any airtoll can be t:rpNS$Cd

by the following equation:

{;6

.~= AreaV

POWF.II. l'nIEP AII'D RATINCS POWEll ,\"1) ITS )IEASlIRE~fE:-''T

or the power obsorbed b)" A propeller wbcseblades arlo!111fixed low pitch vertes 1:3 the tubeof the rpm - J\ relation wbich hokls true unl]the tip speed. of the pr'Opt'~)erapprw.c.hes thespeed of sound and C."i~altered. Ie leu tech-nic:'ll terms, this means Ihnt the power mw;.~beciidlt tlmes 8.'1 gt'el'.t to douhle tfl.e rp~ andtwenty-seven time! as srrcat to triple it. a?:d$(1011, Fer example, on a Wasp }fajor (R ...I:!6().the Icllowlng rela.tiontlhip.."1of l"(Im. ;OI'QIl~ andpower weulrt be N1COUnlCh>d.

I'OW!:RCIt.\~K. rROp All-

rno. :t:lIAfT SHAFT SORBEDt-:Nca:-;r. TtJ:I.{.F:R TORQl.'t TOKQn: BYI'lto-

RP'r RPM LB-t'T LB-YT rr.l.I.F.R10(10 ~7G S~O 2'.M:? 161)l~OI) .'U2 IA90 fiO-li) 5.1021l0() '750 3360 ~~ 12811~OO 9:11 .'2f1,2 11000 2.iOO:lOOU 112:; 7>60 20178 4a20

Th~t\rurt..'ilupt,fy, or ('()ur~. to or-ty O~ Pf,r-lit',dM' blAde 6ctthtK o{ a pil.tt.kuhtr propefler.t ..(1I'~\HlJ*vpeliets at the ~:\mft bladt onale "illn:-tJulre more hortlf'pol\'ta' ror any Mi\'('n rpm butfOoIIU,,1hor6CPOwor Rl ao:n4: lowtr blade "nalt.~ml\lItr proptller. \,W ~ulrt blah bUd.Inilt" ()I' Ir.s tlowtl". l"le\crtl:.~k.~~ the ,..lAUnnbetween rpm nnd bhr> tor An,. J)ro~fer Arid A

!rl\'tU blade ~Hin" ~"'JI In nil ("1\8('$ bt.i Kivollby (0"",1. (7).

TW. l,.btion " known ;'l~J>l'OI)CII('rJoad 4I.udin atllphical form Ii known 1.1$ pr('I.lt".II~I l()1\dcurve.

~ED FOR OPEIlATL,G LI~II1'S

An cJlgitk: mil." be made to Inst tore\'cr, By"pic:kting" it in (l auitubht preservatrve, encMinlit. in proper ccntatner, and storing it JII a eon-trol)cd atmo5.pbere, it .!Ihould lie in tUt gnod con-ditionafter ~\cn.1yean 8.R at the bCR'innlng 01!t.oragc. However, to servo a useful purpose theClUlmc must be run. and i!l bclng run it 151)ubjectto wear which will inevit.al)ly limit. rt...s lifi! span.The previous discussion haa deAlt with the

variow foree set up in the engine. in the prcceaeof producing power. As the throtUe controllever is advanced cylinder Pn.'SlOurea: increase,

RATl'CS

PR.\ 1"1' " \\'H ITXY AIRCJLU'T

and t: e ~tl'\"""~tbn. from thea prew:ur"e!'bome I"'M\tpr. Obviowly lhe~ i!a timtt to theprvuurw at... " that (an be tafely lmpoMd onthe tyhl! h.'N. pi.ton&. link rocts. bt:arinD. andoth('r 1I.,lfhlfl pt\rb. Similat'l.lo'. Lbe contl'Ol of en..air .. "r~1thu)ugh the J)t'l'aWrn01 mtinJr! but a ,"-,Ill mAn)' individuals b,.'lRetheir concept.. of pow ... output in term" otp".reta.tUt of ~ormal P..atod power. A ~ret'tportion of this book ..."" wriLtt:.n brfore thiJ.change &.::d. U rwult.. power 6election dis-c:o.s.9on! #U'~ bued ()D peroentagm o! Nonna!P.a:ed po'Ilet".

POWER. D)IEP AND R~TJ~CS

the policy or establishing tru{$ing nonnillrli..,i~ually appttes onl)' eo the Twin Wasp 'D'and tarcr mode) engines. For pre\'ioU$ a:odcls.manufactured by Pra~t& WhitTlf)' Aire ....n.Ill.. crulee rndng~ appecxlmeted the ge.."Ie_raJlimit! of 0.30 bh.p per eu. in. for me s.iftj(Je rou'serlea and O.lJ76 hhp pet' ell in. 10r the doub~row i!~ri('s. Ra(il\ft~. b.~ on these nUosproved 10 be Po ~~i5fACtO)'Y limit for all normal.lean mixture cruising and haw )(1\"00un ae-ceplJtble (.ombin"'tion of dUn'lbility Md pe....rormance. In Heu oC a posltlve delinition or liteMnxlmum Crut,ir.tt rotln~. tnt usc or limilabn.'1e

PIIA'M' & WIIITXEY AIRCH.~~'T I'IVA. 01. 100

ADDITIONAl, RATINGS

1. Temptnture and ~Ute RatiDp. In addltion to th power .nd &'1'Irnratinn whkhJt'(I\'em CJl)(lno fM"rlorrnQtlc~, lim!Llnsr ccmdhloTlACI( It:npt''Tl\ture and f!'N'jI.un! "rP. spodt\tld b,.thf" E!lgin. manufut urer nd the obNn~of tbese hmila is Mnndal"". Tbeow ,.U"puro:

n. (;ylI!II.lVI' Trlmd 'r(jmf.l(\rt\t\lr\!-ma~lmum1>. OH (l?'ll,t-) Tcmpernturflt-msx:imum. andtr.lnhnumc. 0-:1 "r~o1I.Jrt' maximum and minImumd. "'IH~!Pa'lJfo"url"!--rrUlximum and minimumEIl(:h ur lh~,IIf1 fU!itu:S I" Itt..en lOT ",.r:ou. f'IPofOrlllinK ('(')f1t1I1JiJJl'.Th. tilIJMq~ (It 1Allureto ~\' d'CI .. ,hrJt.t h.~ .1n:ad.1 bfi-n d.tUlI.fd.

~. COI'l1I\1U,n~tlll.'" 'n,\! \:oo\'40ntio"",1 I'\nrmnlnnt~d, 'l'III..o-O'T uud MlHtnry VQ\lrCl' ,,,tin,,,. ""'1u.IlIo:don J'lt"nrl,,:Jtllu Ct')nf.pla ut tnrfr.oi rdiAhU.;h' and duuulhY In .. ...n..,. thoH Ot ~ CCh........ ts.Y

Uf. 26 - Effect 0' Corrf'ltrtuo."'ow., on DurobilltyThe \o-aluea Mowtt in }'''il'. 26 ,_,.e onJy IHlJ'lt'OX-

lmate .and VW)' t\'t!O at. the -amo })er'"ntllJ.f': ofpo~ outpot becau..,_~ of web other f~ as

I

II

POWER. B)IEP A_>IDRATI:'i(,S RATll'iCS

'It U - '.iff W 1:.,1.,.t..mlW"I'MUl'IJsud lyP't' or ;nl't-AllnUoli. ",-: pointtv 1,. und~i'lIt('lO') W InoMYI&.-h'l mlf1f), tw the,; (.(X~lhhIOU. du~p~l UMd.

fuC't, T'I~ T ....,I_ \\',.,." S2C I G hn- fI thud, I"'bun:to,' HHlnK. which f)ttrmit.l lh" tllW tit ~7octane lUi" \\' 111 IOWfr f:l.tiHl-!i. TtUt unl)' ttlr.tt ......'t"t'~ In the! 1.Ii1~'of M:UfOriA1. tif th,"w Ih"I'!\t4HIIU,"" A"fI 1hl\ C;:~Hwr..:lor (IArb ....hi. h ....'\Vdole ~'tjll.~ u, ....HoNl 'u tud 1111,)'4

In tMt,.",. "e WIlInD pr'O\,ded '1IHlh e..,'bur ....tor Itt'tnat t Ir-h I'tm1lllh\: u.. or ~fr Kn.d-=(~I. I'hI' ~r -.dt !..fol mAy be ua'

!'!lATI /( WIll1"NJ:\ AlReRAn- PW~.01.100

r&;t"'* 412 thl\tU,h ~.heve brtn am:t.ud 11)' tho- N'\ I~

GROUNDOPERATJON

I(

-- -..~ ~

GENERAL OPERATJ~C INSTRUCTIO:>iS CROU:>iD OPEllATION-STARTlNG

PART mGENERAl. OPERAT~G INSTRUCTIOl'\S

STAIITIl'iG

GEXIlRAL

'l'hE'N! are a number of rr.ethods for obtainingcousiewnt 8tnr;'r; whh an,)' engtne modl!l )t~orthose tTc!holi$ urc ~r\lAU)' )Cood e\'1.u lbol,lJlhlhl\}' UUI,yvnry conJlidl!l'ahly in delail. Some l\'ilIxivc burc rcwh.$ tor 011\1illdh'idual but fail ;0glve "n.ti~laclinn for ()th~r~; whit. Mme ml"t.h.od4.> 01 the mixture control co duml' Iiuuid fuelinto the intluction pa!lMgf!R may cause the en-I{iue to "hydraulic" (see }.Ia~c73), and theI'OCONof enJriJles damasced by the misuse 0.1 tilemixture control t.eatif1e" to Ole soundneae of thisreeemmeudarlcn, It is recommended thal themixture ccntrol -rernain in idle cut-off at. alltimes that the engine is not. firing except in thoinstances .bat are $peei~JJy mentioned in theinstructions that full()\\',

6.

YKATI' 4 ... HIl",EY .URCR.UT PWA. 01. 100

In VCh:.c.raJ.thn!e ditterent ~brtiAl' p~dUn.:t wtu OOYU .U Pratt \\,hil!:.4!, A\~ratttn)l'infl.; 004: lor ellgi1lfoJ'. usin_' ~t ~pe c.arbu.f'etorliind the oth~rtwo tor ertllinM Ulin~ p"'_'_:Hit" Inlnctfnn carbul'etors. These l,,'tfw l.wnnrn';.

I), 1r itu:rLln type IJta.rt.c.a i.! luted, btrIn tntf'gh:ll\g IItur~rwhile p.dmirS{,

A. 'PdOl\!:0.. It ('t\rburctor bas integral pnrMt':

(1) :)[ove mixtu.re oontrnJ to tull ......n.(2) Pump thro,tle throu~h ,,''''plot.

lra\"cl far number of !Iilrol.el ~I.a.r)' to gin required 1)rim~

f3) Ret-um u..ir.l.U't' control to lui rkh.

66

(;~NI:R \L OPF.ItATtlI(; rxsraocnoxs CI!()ll~D ()PEIUTION-.;;T4RTlNC

;\""1 It ~~Iy ~N ,. f'f* .-art ~drarbc.u -.::.~ _ ..~ 0_*~t.rc.:.! b>:ady Ie rdJIll It- -a..dy'11-1 ._-~ u..e cOtln (KlIcJ t. : nO

b. Wilt: inertia or c"l'tridlrc JLamr:

(1) Tum of]' the ignition.

(2) F"uIU'Open throttle,

(3) Pull propelfel' HtrouJrh about ~ "evolt;;Horu in dinoclinn 0' Dormal ro-'alin., to t*r t!'~tM:.

(.I) Retard throttle and npe.at startincp-"",-

2. r. _..ne 11 u!5dt,...,nm.ed.'n th. (Me: ltp.pt;\t priminA' ptuu1CJunr LO rh....

ume eddulonel primf

h. Itopenl itatlillV pr(l(fdure.

I( It IJ' "dU nnl 1'I000fbJ.c'0 .to". tl': nth~.rh," II l)t 'ilt feu ijr curbu rll:or tor MIlltul'l("lSoniDg.

"T \Rll'C PROU!I)l, tu;, R.-f!.....:fnci withP""_Uff 1,.;""Utln (,".. ,,1"'""0" U.. OM... (" ......r 1,... Ii(l l't~ .'rC""a ....

,.-- 1M 1\.1 c.l'hll'~'" \f , , c lUI"..", I '&If I" h...... 10'1 ,U .... ".'" ,."r I,'" 01.. ,; II lucll 'PIil......"ltdi)!I;II.r.~"."..jr;~., .... ~~ CM _:..1TItl"'_ ..Coli

-ld ..~t ...aI)-'aJ ..-C'_'11&11... ~W'f!L If InfOrtia or e3:nricln 11.&rtt:r .. LUed. puB

t-ruJl(:Uer through in the dlT'fC:Uon o( nonnllrntatioll fOorat 1eHt n,. l'V\'oIUt!OM of thecrankshaft. If dlrec:t eranlnn taru.r it:"ANI tum t.'Ua'ine o't'er lor ei.bt crankahaJtre~oluUoru,

2. Turn on t'u-cl.supply rn)Cn lUitab~ l.ank.NGI~I Keep MIXTURE CO~TROI. IX IOLg

Ct:TorF.~.u dJDd ."t.. ,~ l.~t\!nlr:,. ~.

3 It inerti.a starter i$ u-5ed tart eDe~riArUJ' W"bile prim.i.ng.

.c rrlme:L It luutd priming pump Ia _:

(1) Operate webble pump to m~nt&ln3 pal fofol Jl-ressure or tum on d PC-lne BU.xiJUU")' tuel pump.

(2) Prime.$ 1'ElQuired,b. It Clect.rillllly operated primillK valve 1a

u.....(1) Opuralu ""obbl~ )lump to mall1tain

roquirrd fucl preaauee or turn onI,.)ectrle auxiliary (upl pump.

(2) Prime u recutred.:h J t btrt.& O(C'.rtridKe turn.,. ia ued.. tllf'D

iK'"ltlM '0 "80th On....

6. Operal ... obbI~ JI'lmp to mAinl&m n:qulred(u.' pr-.-urt or Wrn on t!'let'trie .U1t &a1TrUt,! .,.._mp

7. ";nKal" .UUOWr UI' fire ellrtrldn.

K. If dh'N't ('rnnldn~ lllu'I,.cr I. ulW'>li. \liM! to)'4.lt!M,ll1lJ to tum two l"fI\'olullons. WUldt (01'Indlt'Mlon, ot "hvdNtulleklna'." If nnnt'.turn Ia'nllinn to "Both On."

O. Wh(n cnJeint 11tH, reeve mixture font rcl,mmffilAt.ly to .'.ltomAtiC' ejeh posUlon,

II). Ma.nl&ln tOld pl'tlNur. wU.hwobb'", ploimpor fW1nr aU1tlhIUT (Ut) pamP \lntl' .n.h,...,.."..~1... ld. up ap.dliod , .. I p'_"",.

J I. Adju\l;t rotHe \0 malnt.ln a.\)ou; f,()l1rpmu",,1I1 .. d IU'''II.1IU,"" Abo"'IJ,,_" Ie" '&1 pruuu'CI &Iln':. H ,.1111"_"'1' ". ,'I

_ 'f'P'IM ~hlh u: "\UI'II". ~'I\JJ "r.,tlr.. illlJ

12. If Ifqulm:wd wl1h Hnmiltou S~ulldlll'r1~'()unttN:l,.h,hl ty,IM! (not Hydl't)mJl.lh.') IlfV",l.l.}f.r. mfl\fOI ('()rIirol to hiJ,:h rpm (10.... p1lth)

13. When (N. preNIure ~ho....s, AdJUlt lhnlulto \' 04H1 rpm.

It .(_U:~doe.! not ree "~l nuuedUlt~%L W.lh oiP"flt't f'l'a ...._k.i X 1l&rter (ext .....' mod.

eh~GI,.... upelrd! catbu~o ...).. If t:n~nt i. l.mdct-primed:

(I' Continue crII_nking.(2) Mn.lntnin fuel Prcl!JlUff.(3) lfo\oo mixlure control to uutYltlMLIc

rkb tor Jlot mure than :" ~Ql\d3j,(ill J4tum mixcure fontrol Lv idJt ("ut

011' for 5 i>L"Cunds (unle~ ("tlKlII~ "rei.nlunwhile).

IG) It.tcts.!aly repeat .u,.. (3) .IId(of) or.-e :0 three tiJDe:I.

67

1'11'.\. OL tOO

ins:. e.od aU Uat! (!'linden reeeive , combu!tibl~i'~J air ml~"ft rnthe:r than ju.sL a IimiWdnumber 01 pruned t)hndel'~. Con~1UellllY. theu.ndc.Ilrable p~~ of re&OrtJngie U'6 use utw miXUlTe eentrel to .upphorncnt m.. pri.rnin.fuel ~ ia eliminatod.

)M:ead Of priming bet()rf eng-Raing tho$"".~t. Ult prilnint' ,'.utdt ia dosed "lmtJJtafM'-~r with the F>tlll'\~;renglliling awitch. A.i nC()mh~iblo fudilUr mJxtUI"f. raJlJ,oURE, C. - Enlln .. "",bP"I!NUI'e fnjrdlon ( .....buntu... and .au.tSfo,",('r Rlm. 81... u 'Chr-' M Carbu:rflo ..l'rilnll1l:.

Starth,. Pt'OCi(!lllur~

L I"Ild "pili, "On".

Man.\ 01 tM la.l

t, Tp", tl'"iUon "On",

fI, Aft~r engine 'l"ftI.llowly tA"f mlr.u~ eon-trol out or Idle CUl-OO' lu AUlumaUc: Richuliing prime t'L-~ l'eQuired unUI cntrinc i&.Cl.;urd)' 511t.t'ted.

7. Maintain fucl pn."5.Sure triLb .",1111&., fuelpump until enaine pump buikM up t.perifttdtUft ptalUte.

8. AclJ... t ueetue to m.aj.uuun .bc>u.t &00 rpmunlll 011prNlUn .ho ....

/'1(04#, .... lAnn,. .....1t,.,. ...... ltfll,'...,.-.,...ctNt1'01'rttUttr .hAIA 101"""", 11rUI" ,A.rI.-....~cl l:wetU.. tll

6 It .~ulp ... d with lI.mll"'" Slandard co t"""'lIh. t1pe (not I-Ird",maUc) propol"'1' movt control to b.hth rpm (lu" pilCh)

10 Wh.., on P........ "' ..... a4J .. t throttle '"lOW rpm.

MQ\IJmixture c:on~roI t.~("k.,. Idl,. ('ut~Immf'dlatply.

.! tunnnue ~rankin nnd primhuc.

If. abu1-Is not obcah~ within n rea.uDllt.l mo. ." IOH":.,iJ;:.Uon abould tw madt' I" derer.m De th.. (,AU!le.

~un:()' :'!'ARTF.RSStark hi art! ('Q(llmonJy of aM ot four ~:

iDotrtlA. cilrt'Ct (;r.t.u~mlC. ,-vuibuLahun inert i.d rocl er

!'RATT & WHITN&V AIRCRAFT-=---IlIf;CUSSJON

1. Cont.ro1 POI=ilLloft('heckH~'chcekln .. 01Tl:hfip""lt.!()(~ IJl each tns'lneMil .f.oC('e8~l'Ycontrol "hI,: operator m.Ue.certain that an powfl"1)I.ant un)". AI\! iRreadin~ rbr optradun., lUll! .tllt\f-.411 blm~H1f thaT no it4rm ~ In a fIOIIoItlM to taUMda.map.

fl, 111\1l10"Durin .. the ,t;t..,.tlna: pt't.ll.:l.:dUl'OMcerw..intha .. AJIIII de ...r of t.he J)l'opeller befcrutUl'nhtw: 011tho frnltion swtteh.

b. Mix. ure

To. i.,u.lon .wit0 OIA)' be .. nlcinc 1M aircn!1.

IA the eeee of ~ iDj\.oc.1.iOD c:ar-ba.t'etCJr'!, it if ~tiaI that ibe mixturel'OAtrol re.roain 1D idle eut~ at aU

70

CtNt:lIAL OPDlAn'iG lNSTlIUCTIO:'S cnousn OPERAnON-,"AlITI'iC

limes when the ~ .. a.o\ fir'ift ee-eept in the i.nst.A!:.Ce5 'lJC'C'll'!caUr mee-tinna! (see page 67). If the tutl b .,.,.,.pressure. it. is discllAf"IItd j.DlO the indue-no" ~y.!t6n (rom the c...rbu~tor when themixture control is out or the Idlt ('1)~PQslt[ou. Some of the ditthnJVild rue>lrttj,)' tClUeet in th lewer Intake pipes and(aUII(~ the pnl.'in(" to ".u-d,.ulk'" whtnIIll\rtina l~ atWmpled_ f)tti di~harpdthrou:.h the rutl drain" .. pot.nda: ,~hAJ.'\rd:.

d. ~........ horsu Cottbol (~.._..ppU..t.Io)

Thu .UIMUthK'",.,. ('on1rol 1I)\'or fortIoina1o.t"'$Ce. lVrO-lIpc~d l.m"ln,,, "hMItIbu V1ac:td In t.he low 1>o"ltiol); (llid furtw.o.. t.ae tnllhlO$ in ure maiu IltllW'tII(nfulrAI) JXIrI'trlon. 1'h1. CIlU_ the 1111111l'nllM IOId Lo be Impot.ed on thlt imp(ll1('rdn", f'll.Irtnr ,"-rUn&,.EllW'...... " I"" tutbotwptrth.U'ltrt .hooldt.a\t the turl.lOl.UpetThlU)t,.. tofltml I".ho -or ... ,11....

(.. rltUf'riur "~.1and Carbuf'tior AJrFIlter

With ecnt ... II.I>I. (, ...I.bl.) pitch pro-fMlIIPrI. th. rpm C()ntrol will tuw. beenplaced In the hbrh rpm pot.lHon at Lb.tim,. or ~h\!Vf9\'iou. ah~t,..dU~D. The conlrul ~hnuld Iv(t In mi, pclIIilioa toord"t to reduce the l...ad on thf' tnl\nedunna d'le start.ul and "'Ar'll'Hlp prnod.The UC'epllOn~ to lhia nal4 .... th Ham-ton St.a.Dd.t.rd countf""-fillht propel"'"ft.~jtion or\&ri&bll! pltfh-bu.t DOC.the Jll'dromatic). Wllb t..... pf'OPf'lle1'lthe #nginc !oould be "hut eo .."t\ .. ILh thepropeller rpm control in low rpm (hiJ:hpitt-h) pos.id(l!l. TM, II to mmtl thftpropc1Jer-operathlK cylindtlt to ProltdIt front dU&l.and to ~",pt1 tlu: oil fromthe- cylinder tbat. o1h,,-rwiM mlaht roo-Ital in cold \\ruther. Tho propelr coo..tml "'ould nol be ahllt.d '0 bleh rpmun.bl alter stal'ting th~~n" and ob-tainmjl oil p~

Carburetor Air heat. must. be in the (old..,.1

PRATT & \VHI1'I\EY AIRCRAFT------- PWA. 0[.100---t. Cowl Flaps h. rut! Supply

-

I)lIrl", aU ...... net """~"" of .IM."fino I. I, _01.01 u-.. .h .-1""po (........ .,.~".,.bl.).,., (II", "'*'nprcUt. of OUllldf. air l.emptratuNor lh~ cemptra,u .. 01 1M (:,hndr:rh\\Ad... Tht: ',nlticK. ham~ "'0.1 ..oth-er pow.rplunt ttfoma. r.qu.in aUpo;!lIlbl. Circulation or air to pN.,c.nl."erlou8 damuMu. ChlltiP.l ot 0-. (OWln"f'" to lM;(;4:1(lr&WI thl ....art-up wU1' d tc tiUmlnr n( the hwulaUon on UUtIf.IUonI.,,",,

~ nfH)' tac-w Ule P.Jd .u~ly.hou!" b.- turned olr v.htn tM '"ain.u. N:.ul down, Q.l\d not turned or. usullprtJ)l.raUon for .tall1u~11 made.

I. Th",UIhtnc pres!ure rtta.rdleu o! the thnrt...U. pos:tiun. 11I)WPVef, (ue...d.o.. isclOR!y l'P':aud to d~poGtioCl (It thethrotlil" but in a manner which dl6~rs.tMtc:"'-eenthe two basIc types of carboNtOI'JJ.

u) Fl4l.'l' Carbl,It,,'o"1ft d:e miin, ,..ru:.e or Gp("ntiun thi5type of ClU'but'fttlr tw::.Ub ... fotlur.!y ...bf"l'" dcfuLtc Pftllure we.tercmal nf~u; bthreen the kUecli~('ha.r~ .u~d lhe rue: in th. boWl.I( th.e throUJo II t~ fA' ady.t.ftld.'hi' diff ... n,iGl bttacua I_III-rifnt to proch,... lht: requ.rwd ftOW,.,;th the rUllh.-. ""at tze anJinttann.ot prope,i, fl,.. al'Xl. lD allere h;!lt1. bac~r1rtt.l.. ,"11 uccur,

(2) I', uee ('.rhnretOfUuring Ih. alAnI.. aed lellln,p:rkMI the PR..u,.. cal'burewr Ill'."h~ (uel Ifill"':,. U IM......wt 01th. J)O'itJton ot tht idle vah tHehI, d'rl!ttly '."lod to lilt u,rvu/t.Alrftow h"" no VIlM upon thlqUAntity ut (utll dhcbat,", tr thethrottle I. lUG tar adva,M*I. th.f....J _harte ..10 be _ ...... forthe a.moun! of &lrft.u ... that it beJllSdrawn tDt.Od~. ('ylindtn wHh l.btR4Iult thA~ Uhl 1'r.llne wffi be O\.. r-I.. ded,

In " ..tUnA' lb. thn>eUe 0.-01,.... bdore..larll.nJ". the PUtPl*t it to -="'" ~pn.p.:r fuel .. i, ratto tor comL*1j~ aRIdlht th.roltiA: c)])tlil' It ". atrectec1 \I) the1) va of earl.lut"Lor and .t.4rtfr em.pJoyed .. 1'"or@X'amplu, ul'tridMe .lMmn.wh(ch surn th~ en,h,u ever at hbctwrrpm than olb"r tIP" ou.d COIUIIIIQuent!tprod1.M:e mare Ai.... throaab tAt car-...._""I..,.. .iJJIbtiy .,oIor Lh.... t..openinl".

2 (1fArln,lC"the En&'JneAttt.r tho prevloua .but.do\1.on~ t.bit 'If"IU'Dlrwldulll oil tliDtPn, to the power RCtlonsurl.tes ttowi downward totr1ld the Iow'e.rqlln".n. Some of thisail _ .... tiltpl.ton and piston 1'1l\J'i. ~ma1at.ulr f1'the combustion chAlmbw. U sul5rie.nt. Uquidil'l Prtaer\t. the true CQmp-reaaioo RUO wID

(;R(lU!'II)OI'F.R'\TlO:,\~~T.\HnSG

be ralM'Cland txtl'f'mcly h!Jh )11"f'''IUnl willtwo prod~ \\h.n th~ piawn of tho crHn.tltr h~movf'd duwnwartf on lhu cnmpt'C,,"won. ,1.tOk~. Thf'1IoCI)nlSl!U~ (All l;(l rail'it'dto '11th "0 txt.ent thllt dw.ma&.rfl ttl the cyUn .der. PJ.Jton.or I;nk rad .. ill NUJt. In es-

I

t.reme instan('" ~ -pisu,n m..y al"tual1y~bot.tomuain.t. thp Jjquid. ThJs ill knc ....nall "hydrau~ickjnlll'" the engine.

73

PRATT & WIIITN};Y A1RCR,U"l' -- PWA. OJ. 100

To prococc thft fnr(Ml 'lIlah . t lhll J)OIIl!hll.Ity, nuv esee liquid tlhould t.dr.n.od uutIt the ('n~'nfl hut' aluod Idlu tor ."0 houn01'mon~,'thl, I. d

CROUXD OrERATJO~-STAltTING

WJrH eNGINE NOT RUNNIN&AN AUXI(APY PuMP, CiTHERWOBBl.E 011 eLECTRIC BOOST,UU5T BE USeD TO RAISEFUel.A8Cv~

'Vet TA,;Jt7

While pulliOV tho propene. Ih ...... b by baDdor with che .ta~r. tho operator mUlt be.I.rt for lillY.tm of ,h. pi.... beillJl (0""",AraJnAt unuaunlly biJrh c:omprlMlon. This,..m be e\'ld\lucedby A ",ddtn ~~an~~ I.uddtn .Io-ing down or c:omplere.toppaco.Thla 1.1aull1dent. Ind.iuUon that all uceuquantity 01 Jilluid J. prese.nt in tbe ~crcyllnderw, And any tUIther" ..t.tempt to turnthe cnsdJ\e O\'eJ' will rt6uJt in d4lDl\g e,

If the nresenee 01 liquId La ,u'pected. no-mo\'@ l\ "park plug from eu.b of cbe boltom('ylindeN. belu~ turning. the engine ever.Thil'i 1$ etlpe(!ially imporUnt wb

PlrA. 01. 100

In the (.Me of pftS.wre jnjed.i.QD c:pbure-tors, th. minimum pI'tMUre Nqui..m .... ll\'}try with the partieular CTlgine r.nodeI~andlht PTf'.ll'l.Uru(an be spplied .cd matnWned,.,;thoot da.nPt. p!'OVid*, \he mlalure COntrol i.ll kept in IdlE'eut~olt until the enl'neftres.

If tho mixtu,. "",tmI ia moved ""lof tdl.cutnfl'. fuel will be dilorhRrled Into the In.duetlcn .y&tem. Ai the 'u~JCint \I not tum-in,. o'"er. 9ft1)' the air COGtained l" ttt~s.uptr ..el\Ql'Q'fIr w ilI ahlorb vaporlud fuel on..drRin \l11\'11'will corry aWAY only a pontonof lhtllquid that the-c.arburet4rdi~The bal.n"" or lhe liquid full poun to.o

uee of the prime aad enpging the starter.Thu is doIlrahle lA order to minlmile t~f')I)Ir.&ibJt ~eci of raw fuel lying IMide the..nrine.

A. the C..rbuM:()I' CAnncM. ~u.,,')1)'th! cyLnct.n 'l4lrh. cornbll.t:ble mltt.1.r"eof a:r.ndI~J "d~h(MJl ~ln(,k:nt .Idluw. 1twttHI!UnI~rllltr churt mu...1 be 11I'tl>n~t by otherr.~a""Jht air ~lItaint in the

"a/IN~tfIItt ~

'It 21 ((ftc'!" r.napetOf.,. ..... remH "f"'.,." ..tf'm. I " atOmll,4!d by nuulw to .... ~tht vaporiD"Jo~ ot U. tva r..nd ill d ..Nf1tf'd into tM I...dwtlon .,.atem Of" th~IlIb",. potU ot :.be ~4Pc,1I Jera of thf'~flK"1ie dependm. on thl typtt at pnmlft$'"ytottm on 1M enar""'l'h. Id\:,d prim!;) .houkl (ontAin eoou$fb(omplctely '''(lJ'lOrillld 1,,..1to tlU th. Indue.

\"l SM" tx. ..t, comuUlubl. rUtl."r,I."tu ......A. ""A~au i. inlJ.vd\lctd by tumlUi( Ih" niX' '-' &.ht fuel ...', much". '" ,lI t".n"'ln'~ I"W'rCI h,. tht priml'::)C tvol rio"" u,..til !l.arlL l.culll.' it. ar.d A lI1art i. aeeum-phtJl,,-d.

If 1M nublldl!: lur ll.:mpcrn\\U'C til Ahovt!73 ... t~ C)I,)t' It the tnginfIJ I" \\,111111 f'ruml)rt'I\'lou. o~rMioll, )l I..IJouil>lu 1hnt 1'\11'tit!.nl tll\:'lo(h&'l")I.I ai, l'(':m:dnJl In Ihu III..du,,dc, t)'tttm lUI a reKu.il ur l'C.!Iidunl fll~'1to obi ...", MAr\. Under Ult"te ('ir'CumM~l1j"".:-.0 pnme I. rt'

PilAT!' &c ~1l11'NF.\ AIRCRAFT I'WA, OL lO'1

drawn intn the etl~lno during ('rank.i";e nr.d atl~t .d.art.n.. It aids inf'S,tun,aCD~-te fo\'aponLlm.-upotb.ll-tiftr of the cvkl a:r ~rft.rr..._

(2) C'_rehu'tlor Air r#mp.tnllu.re: T~ 1:1t11

(;E.\"l:R.\I. OPF;RATTNGl:-;STRl:cn016

(:. Suur('(,1! (.1 PrimiXl! Fuelfuel to!' tbe pnming aY$:e.tn i$ com-menly provided by:(1) Priming pump inte@"1'31with e.~""

buretor (float wpc eal"bunltor)(~) Hand plunge? primir.g pump(3) Blectrle aclezcld primmg valve(I) 'fhl~ {Iriming I"'I'QI~whid. 16 tate-

gl'at ",ltb tI..o. jarl ....no1nr (the .,..".Ailed ~eltpriminK ta.rburdor) isactually the al"u-.If!fI'lung pump ofthe carburorer, PlirniD.I is eeeeee-ptiahed alii foliowl:

(") Place mixture ron.rot in tuurt(lh. Ihi& aIJo~.. the al"bvre-lor bowl to be vented,

(b) Raise tud pl'0!3Ure to 3 psj.'I1ti" hilI!>the carburetor bowlwuh {,,(oJ. Cn'atcr pre::s.su..remay cause the C'3rburetor toov~anow.

(c} .Hove mixture control to runlean, 'Thi! o;,ICnolf Lbc ~'\'from the aeeeleraring pump tothe primer dilsb-ibutor.

(d) l\>lovethrottle b3c:kw~rds andforwards through Its (ull:1'~vel, This J)\irnJ)! me fuelfrum the carburetor throughthe primer lines to furnish the

prime. The number of -atrokfd:of the throttle 13dependent onthe amount of prime de-Sfn!d.

(e) Maintain Iucl pressure:~ P!il ~orelil! the carburetor bowl" librue) after two or three strokeosQf :he ,hl"OttiC.

CO Iteturn mixture oonlral to (unric-h.

(2) The hand priminJ: pump iA ulW'dtneoniuncrlcn with (lIlgine U~t:I;lla~tion" f'(fuippE'd with (lithE''' flClAt orpn>~RUrt' injf(:ti()n t:RrburAlQr.l. Th..

lH"imtnsc pump Is A plU))JNt' typ

I'M TT & WHJ'fNEY AllleR.4FT PWA. 01. 100

(b) 141ae3 psi !lid p......are willi...obbl. pu.m-p Of" tum on fife..Ll'lCnuxil iary fuel pump. Pres.-su rfl La ftt:U

';':N(.R.\L OI'IlIA'II'C INSTlIt:C.7JOSS -GROt:NDOrERATIOX-STAlln,,;

{c) Close pri~r lSwitch (or re-qui red time which is depend-cut on temperature 2.00 theparticul.ar method of Imrcdue-ing ,Ute priming fuel into tMena-ine.

The actu.a! amount of prime is "tlT d.iflieullto dflt\(' C;XMtlj.. As pl't!\'iou.dy pointed (lUt~tempenuure ia {L I;:u'~'i:f:Lc~ol'.With the electricnriming valve, fuut p!"e!surewill affeet theamount of actuat prime disdu\f1:(-d. by the prim-ing n..mdc;.i. \VUh the IIIP,j{pl'lminK C'Arburet4rand hand pumps, the manner or operating themwill dfm the teeet amount or prime delinred.In addilion, the i~dh'idual t~hnkr~ of the operator will Ml'eet the nn~ount or primiu," de-ail'ubJe. O'le inrlh'idunl m.'\Y JlO through theton~f('llth'e seep, or tttartinlC with \'ery eXActlimi u", 1\ minimum or 100t molion Qnd with \ery small ever-all dmt. fM the compf.ett oPtratlrm. Another Indl\'ldunl rt1il,y not IWtrOrm lh. 1m