Combat Aircraft: AH-64 Apache (Combat Aircraft Series)

50 Pages·1992·7.46 MB·English

by  Rh Value Publishing

6 OSPREY. COMBAT AIRCRAFT SERIES
AH-64Apache
BILL ~;UNSTOl\
COMBAT AIRCRMT SERIES
AH-64Apache
BILL G "ISTO"l
. "'. . -
1
OSPREY PUBLISHING LONDON
Published in 19l'l1;1)\
()sprcy Pllhlishin/-CI,ul
~Il"mh('rClI1llpany"llllc{~'(lr1-{('Philip(;nJup
]2~J.I I.Ollg".\tTl" I~lIIdon \\'(;2E91.1'
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(:lIl1!<IOIL.I\i!l Contents
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1_'\Il;11h..(lit-lin'111"1)-11i'll>l~ Chaple,- I:
l. rid\.· l)csig"nand Ik\'c1optlle1l1
(i~9,1:I:\T)~ U<;I~:\:I Chapter~:
Technical Featun:s
I.';I~N(kF,1IF,-i':!I-I Ch<lJ>ln:\: ,
ApadlcSI'll~()r,~ 17
]'ypl.',~ctiJrFbirplan I'h'!IlI-I)l'I'M'ttillg"I,Ill. Chapln'l:
I'rintl"dh~ l'rllost 11lH':l'IJa!ion;t1 Book I'rodllrtion, AI';lChc\Vcal)ll!lS
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Phllil>g'~lph~:'I'hl'Illlhli,slll'r~\\tllihIlikl'II)Ihallk
:-'IrIlOlllldllxlug-bs(llug"lws)andIhe lJS Ik-paJ1lllcllt
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,
1
Design and Development
FE\'V FLYING machinesareas menacingas the desigtKd armed helicopters were considcrcd. Thc
armed helicopter, and no armed helicoplcr is firSI 10 be built was sm;lll, a development ofthc Bdl
more menacing than the apTly named 17 Sioux called the l'vlodel ~07 Sioux Scout. \Vith
Apache. Though dull olive grey in colour, the only ~60hp, it did well to larry a crew of two-for
Apaches look black as they come thumkring ill, the first,ime in a slim tam]cm cockpit reminiscentof
making the air for miles ,lround vibrate wilh the a fighter-ami a chin turret with two machine guns.
Illighty power of their threshing blades. Like <!m: Illdeed, small wings were fiued to help unload the
some armoured insects, They dose with tbe enemy, rotor amI provide attachments for rockets or other
shrugging off The hail of nrc directed against them wcapolls. Significantly, thc gUlluer was in the nose
;llld finally picking offlhick-skiutlcd lauks as if they and the pilot I.>t:hilld and slightly higher.
were Aies. Vo,lilhin secouds [be Lllrobbing attackers
havevanished, leavingbehilldascelleofcarnageand High-perfonnance requirement
(\<.:sobtioll.
1]IH[clliably, the Allacllc is il11lJrcssivc, ,unl C;dCLl \-Vith increasinginvolvement in Vietnam,andhelafed
laled to strike fear into its CllClllics. All tile sellior recognition thal existing- armed hdio)ll\(TS were
COltllll,llH!crs of the US Army from President merely ordinary transpon11e1icoplers on to which a
Reagan down !l;lve singled it out for special praise. few weapons had been fastened, Ihe US Army spellt
NOl ltlltypical was the commellt of Brig-(;en Ellis 1964-65 devising- a specification for a specially de
D.P;lrker, Deputy Director for Requiremell1.~: "It signed armed helicopler. R{joicillg in the tille of
gives corps ;ll1d division cOlllmatH!ers Ille ()P!)()J-rLlll Advanc(.'"(1 Aerial Fire Support System (AAFSS), the
ity to capitalize on more ofthe principles ofwarthan requirement called for a machine of unprecedented
.
. .
with allV other system thev han'." But ;llllhis is only. performanceand<:apability, with theabilitytoHyand
one side of" the coin. fight extremdy dose to the ground even at night or
The other side is Ihat, whereas the Apache was ill bad. weathcr. III .\larch 19GG Lockheed was picked
planned to cost $1.4 million, each oftoday's helicop ovC!" II othcr coutcstants for what promised to be a
ters sets back the US taxpayer almost len times that giant programme.
amonnt. And \Varsaw Pact armics are more COIll The first of ten prolOtypes of the AH-56A
pletdydefend(.'"(1 againstairattack than anyothers in Chcycnlle hegan its Hight test programIllc Oil 21
hislory, with vast numbers of highly mobile SAMs Septcmber 1967. Powered by a 3,925shp General
Glpahle with one shot of blowillg an Apache into Electric TG4 engine, it was in some ways almost au
slllall fraglllellK (:0I1troversy over the viability of autogyro or even an aeroplane, because in cruising
or
hattlefield helimpters will cominue, but the point Hight much lhe lilt was provided by a wing. The
must he notcd Ihat 110 nation makes g-reater use of main rotor was almost leathered, and "almost the
tbem than the Soviet Union. Moreover, in Ihe new entire engine output" was supplied to lhe tail gear
Havo<:, helicved to be the rVli-28, that country h:ls box where there was not only the usual ami-torque
paid the Apache the most sincere form of compli rotor but also a propeller giving forward thrust.
mellt possible, in the form of an apparently direct Cruising speed W;lS ~421llph (389km/h). Avionics
copy. weresaid10 he "morecomplicated th;-lI1 a F.-52", with
Early helicopters were incapable ofcarrying lUany inerti;ll and doppler navigation, terrain-following
weapons, and it was not until the I960sthat purpost:- radar and amazingly cOlllplex systems for aiming a
noseturret with a Minigun orgrenade launcher and
a belly LUrret with a 30mm cannon. Missiles and
rockeLS \"ere fired from under the winh'S. So great
were the problems and cost.s that this bold and
impn:ssi\'e machine nevcr went into production.
ThcArmy'surgent needs in Vietnam \,'crc met by
thesimpler AH-I HueyCobrd., produced \'cryquick
ly by Bell as a private vcnture. In a brilliantly
successful programme, thc Cobra has beCII con
tinuously upb'Taded and dcveloped to such all ext.cnt
that LOday's AH-IW l'or the Marine Corps has an
installed horsepower of 3,392, compared with the
original AH-l's 1,0001 To a rough approximation,
lifting ability i... proportional to installed power, bm
me Cobras find it difficult to opcrd.te except by day
and in clear visibility.
rore
Abo,·C',19"mock-upoftheHughesYAH-64Apache,
Warsaw Pact tankthreat runnuortht:winningdt:sign,whichwastochangeconsiderably.
Accordingly, in 1972 the US Army at last got iLS aet FouryearsintotheAAH progrd.mme, in 1976,the
togcther and, picking up where the AAFSS had left Hall Edward A. \fillcr, Assistant Secretary of the
off, launched a programmc for an Advanct.'<1 Attack Arm)' (R&D), said: "The AAH's night vision and
Helicoptcr (AAH). It was vinually forced into doing adverse weather capability, in concert with its agility,
so by thc awesome and increasing power of t.he speed and vertical acceleralion, will deprive any
Warsaw Pact armoured forces facing Western advancing armored force ofilS security. The AAH's
Europe. Il wa!'>recognised that thecapabilities prom
ised by the cancelled Cheyenne were not merely Iklo...:Thetwop~ofBell'srivalYAH-63losingde$ign
which,amoOlgodIerthin,l;S,putthepilotinfrontofthe~nner
desirAblebut absolutcl}'essential. andalsoreaturedatriC}"cle-typebndinggear.
Above:TwoLockh(:edAH-56ACheyennesflyin.e;,werthetest
facilityatO"nard,California,1968.TheAH-56A:wa$cancelled. was iJ different story. Bids were all in by 1 .\Iarch
1973, and on 22June of that year the Army picked
maneuverability will enable it to dt:srroy tanks in Bell and Ilughes to receivecompetilivedevelopment
rocky01' heavily wooded arC<l~where previously they COlltr.lCts, Each wastobuild two Ilightprototypesand
would havebeen relmivcly s.afc from air<luCiek. one GTV (ground test vehide). In addition, Hughes
"Soviet and Warsaw l~lCt units are .....ell equipped received an 'l\\'ard to develop a special gun for the
for air defense, and the AAH is designed to survive AAH, BellelectingtousetheX\'IIR8b'l.ln byGener<ll
111 the hostile environment th<..'SC anti-aircraft Electlic. This partly explained the sUtrtling differ·
weapons ",;11 create. Its abilit), will m'lke it a \'ery ence in the two development cOntnlcts. Bell's being
dusi\'e target, and it is Glpable of sustaining (sic. he lor $44,7 million and Hughes' being pricc..-d at $70.3
mc:.1II1 tosay 'surviving') hits from 12.7mm machine million.
b'l.lIl n>llndsand,in somevital areas,23mmweapons. Bell'sdesibYfl was the \-fooel 409. given the official
It is also l."lluipped with an effecti\'c illfr-I-red sup designation VAH..63. It was the smallest helicopler
pres,sion s)':'>tcm 10 protect it from heat-seeking mis Bell could dl.:sibYfl while still meeting lhe se\'ere
siles. The AAH, with its night and advcl"SC-wcather mission rC<luirements. The 1700 enbolnc..'S were
Glpabilities, will greatly reduce the qualitative armor placed quite low down behind the rolorgearbox, the
ildvillItagc !lOW el~oyedby the East:' cowls being blended into the fuselage, Ahead ofthe
rotortheentirefonvard fuselage wasoccupied bythe
Five-company competition tandem cockpits, Ihe pilot bein~ in the nose and tl
CPG(copilot/gunner)hehindand slightlyabove. The
The AAH promised to be a m~jor programme, and XM188gun, a three·IXlrrcl 30ml11 weapon related to
live comp..1.l\ies fought to win it: Bell Hdimpter, the M61 fighter gUll, ,'{as mounled under the ex
Boeing Venol, Hughes Hel.icopters, Lockheed and treme nose, the visionics and sight system being
Sikorsky. The one firm that could nOl lose was funhcr 1l<ICk underneath. Lmding gear was of the
General [Iearie, whose speciallydesigned '1'700 tur fixed trit:yde type, with twin steerable nose\vheels.
boshaft engine had aJready been picked nOtonly for The slender tailboom was indinc..--d up....'ards 10 gi\'e
the AAH but also for the even more numerous dearancc ror the sweptback underfill at the tail,
UTTAS (Utility Tactical Tr<lnspol1. Aircraft S}'slem) which wasalmostas bigas the upperfin carryingthe
whkh waswonbythe Sikorsky$-70(VH·60A) Black smallhOtizolllilllailonlOp,theUtil rotorbeingonthe
Hawk. As both helicopters \\'ere required to be end or the wilboom. The main rOlur had just two
twin-engined, G[ was fairly safe in planningtobuild largeblades, Ihediameterbeing51fl lOin (15.54m).
5,000 oftheir new engine. But for the AAH itselfit Rearingin mind thalthe missions and theengines
5
were the same. the Ilug-hes Model 77. designated award. 011 ~~.Illile 1975.<11\(1 hy 19SqHenllx:rit had
YAH-64. could hardly have beel1 lllore different in completed the 50 homs ofrunnillg necess.ary Ix:fore
design. The engines Werc plan::d in separate boxes first flight ofeither flring prototype. The lauer was
sfanding away fmm the rather lumpy humph..·Kked designated AV02 and AV03, meaning Air Vehicle
fuselage. driving via diagonal shafts frolll sep..'lrate 02 and 03; AV02 made its lirst Hight at the Hughes
gearboxes looking like slllalljet inlets on the front or Hightcentreat Palomar, Calilol'1lia,on 30September
each cllh.-inc. The transparencies o\'er the cockpits 1975, one day inside the deadline. The first Bell
were hugc. and the crew were seated the other war YAH-63 lIew next day. right on the deadline. at
round COIll!l<II·e.::d witlt the Bell: fhe CPG being Arlington.Texas. Ilughes' AV0311e\\'on 22 No\'em
markL-dly lowcrdown and in from. bel' 1975, while the second Bellllew 011 21 Decem
Likewise, the positionsofthesight s)'stem and gun ber.
were re\·cl~'<.1. the.:: sight being in the llOse and the By this time the IllIghesdesign had gone through
gun 1Il1dcmcatlt. Lauding gear was 01" the tailwheel a metamorphosis. Mostsirikingofthe changes were
type. the main units hiwing ungainly long legs slop al the tail. where the attachments for the tililplane,1I
ing diagonally bach/ard and supported br shock the bottom of the taillxJom remained unused. In
struts attached between their mid-points amI the stead the fin "'as extended upwilrds. with a SIl'lIlgC
longeron at thebaseoftheC3noptC's. kinked shape and a G.tInhert.'(l (sideways lifung)
aerofoil profilc, and the lailplane was placL'C1 right al
Prototypetail details the top, pn~('-,(:ling far ahead of Ihe top of the fin.
The nose W;L~ rc(k'signL'l1 with different sensors,
TIle tail comprised a "crr low-mmllll,ed tailplane large cOlllpartlJleJlL~wcrc addL't1 on eac!l side ofthlC"
(horil.Ont'llstabilizer)andaslightI)'swepl fin GITI'ring nose for avionics, and the ax:kpit and Gmopy wcre
the tail rOlOr half-\"ay up. This rOI,or was unusual in tmallyR'Clcsih'lled witll giant flal tr.lllsparelllpancsill
Ihat, 10reducenoisc. the fourbladeswcrenOi spact.-d strongframcs, tile light-haml windowsscn'ing;L<;lhe
al 90". The main n,tnralso had four h];l(k's, and was access doors. Finally. in tht.'SC init.......1modificauol1s.
remarkably small. though. like the Bell nnnr. it was the main-rotor mast W;L'i extcmk·d upwani<; by 9.5il1
full}",miculated with pitch-changebearinhTS. Rapping (~'I0111Ill), lx-c..'llIse ill cxtrcme Righi 1ll,\lI<kLlvres the
hiubresand drag hingcs,
The Hughes CTV. Gtlled AVOI. r:<ln iL~ nnors for Below:1neHughesAirVehiclesAVQ2and03onICSIin 1976.
ThoughclearlyApaches,lheydifferedinalmQSIeo'errrespecl
the firsl time cxactly IWO ),ears afler the.: contract fromtoda}"shelioopler.notablyin!henoseandtail.
bladescould rub across the top ofthe canopy. explained later. this emerged as AGJ\.I-I14 Hellfire,
During Phase I testing- availability of the two AVs and in am<~jorspecification change in February IY76
had been consistently above 86 per cent, considered this missile replaced TO\V as the primary weapon.
all exceptional achievement. Atotalof850 hours had Bell and Hughes worked furiously to bring their
been flown withoutaccident, ,Itspeeds lipto225mph prototypes to the stage at which, in mid-June 1976.
(362km/h) forw,lrds and 32mph (83.7km/h) to the theycould be delivered to Edwards AFB, California.
side and rear, at weig-Im 4,OOOlb (I,814kg-) hig-her for Army competitive evaluation. At the last minute
than the desig-n mission weight and with lateral and one YAI1-6:~ h;ldan accident,on 4June,and the ReI[
vertical accelerations never before reached by a (~TV had to be frantically brought up to Hight status
helicopter. A sustained rate of climb of 3,500ft/min as the replacement.
(17.8m/s) had been delll(ll\strated, and prol()Jlged This did not help Rell's chances, and another
testswith thecompany'sown XI\'1230Chain Gunand factor in Hughes' favour was the company's decision
2.75in rockeL~ had shown the YAH-6'1 to be a very al the st~lrt of the programme that it would necd a
s1<lb[e firing platform. bigindustrial team toensurethatthe highestpossible
level ofspc{:ialistexpertise would Ix: applied toevny
Missilearmament major part. Apan from GEfor theengines, thisteam
comprised: Bendix, dcnric power system, and main
III theAAH specification the primary armameIll was transmission shafL'; and couplings; Bntea, hydraulic
to be eightTO\V allti-tank missiles in twoquadruple flight controls; Garrett, engine IR suppressed ex
launchers, though theprototypesdemonstratedtheir hausts and integrated pressurized' air systems; Hi
ability to carry double this number. TOW requires a Shear, canopy and crew escape system: Litton (Preci
hutIlan opnatar to guide it along the lineofsight all sion Gear Division), engine-nose and main transmis
the way to the tal-get, and this obviously tends to sion gearboxes; Menasco, landing gears; Solar. gas
fOl-ce the helicopter to expose itself throughout this 1UrbineAPU (auxiliary power unit); Sperry, autosta
time to enemy lire. In 1973 the US Army began bilization; Teledyne Ryan, airframe struClure; Tele
development of a new-generation ami-tank mi~sile dyne Systems, !-ire-control computer; Tool Research
which would not need this form of guidance. As and Engineering:, main and tail rotor blades; and
\Vestern Gear, intermediateand tai[ rotorgearboxes.
Below:FiringsomeofthefirstFFARs(folding-finaircraft At theendof [976 it all came rightfor the JIughes
rockets)from AV02.,incffedtheveryfirstApacheprototype.
AtthistimenooperationalsensorswerecalTlcd. tealll. The AII-64 was announced the winner, and
7
the company also won the gun competition with its pre-produClion prolotypes, AV04, flew on 31 Octo
unique Chain Gun. Ilughes immediately H.'ceived a ber 1979.
$317.7 million COntT<lct for FSD (full-SGllc develop- Here was yCt another new arrangement. with an
ment)oftheproposL--d productionhelicopter,indud all-moving "stabilator" mounted low down right at
ing the construction uf three more prototypes the backofthe helicopterextending fromjustabo"e
AV(}il. 05 and 06---the I:lSI IWO with airfr.IIllc..'S sub tJle vel)' tip of the tailhoom. 111is enlargl.."t! surf"ICe
contral..1ed to Teledyne Rpm at San Diego. wasdl;ven bya hydr.llllic1>O\\'er unit linkc...d into the
'11lf()IlgholU 1977 HlIght.'S Aew theIWO prototnx..'S Aighl-<:omrol and autosu.h system to till the machine
at Palomar, testing and evaluating a "Mod I" pack when necessary but in normal flight 10 prcSCI'\'e a
age ofch;ll1g-cs which earlier flying had shawl! LO be horizontal auitude 110mailerwhat thecin:umstances.
desirahle. These chauges induded a funher Gin Thl: new tail also had a vertical fill 3in (7Gllll1l) taller
(152mm) increase in main rowr mast height. SWCpl c.'lTying a modified tail rowr a lull 30ill (0.76m)
hack lips 10 the main-rotor blades to reduce com higher up. ["en this was Ilot quite the answer, and
pressibilit),. il redesign of the I<lilplane to have a 011 1'1 March 1980 AVO"! Acw with a smaller slahila
re,-ersed planfo~m (slraiglll 1c;lding edge and ta lor, followed two days later by the first flight ofthc
pered trailing edge). a 3in (76mm) increase in dia AVOG whkh also imroducl..,<1 a tail 1'0101' of lOin
meter of the tail rotor, and inslallation of Ihe first (254mm) b'Teaterdiameter.
p"iItel'll of IR suppressed cxhalL..t using not the Backin f\larch 1979AV02 hadGtrriedOlllthefifSl
engine·dri,·cn fans originally spL't-ified btl( the (ground) firing ofa Ilelllire mis."iilc, followed laterby
Hughes Hlack Hole Iype()fp"lssi\'ecoolingbox using airborneshoL..ag<linsldesignaLCd ldrgets. In Oclober
self-illduc("d airflow to mix with the hotgas. 1979 02 Glrricd 01lt the first autonomous firing,
desi~n;lling Lhe larget itself with its own Martin
Phase II testing \farieua TADS. Butits sister.ship 03. was fitted with
rival sensors by Northrop ;..Jortronics, and it was not
These changes had all beell Aown by May 1978. By lIntil f\'!al'ch 19RO that the Martin installation was
this lime AV02and 03,aftera mmbined lotal of720 :.mnouncedasthewinner. This naturallyaffected not
hours. were grounded in order 10 be broughl up to only the shape of the nose bUI also the brian! side
full produoion SL.indal'd for Ph<c>c II testing. This avionics panniers. Yet another visible ch;.mge was
56-month pro(~rramme,coslcdat$390million includ that the flat gL"lSS cockpit panels ....·ere replact.'d by
ingthethn.'ceX{T<!PT"Otot)pC_'S, \\~d.~ thefinal longhaul .~ingle"cul'\'<l.lure bulged windows gi,'ing a "K:W
thai had 10 be completed prior 10 Ihe SL.i11. of almost directly downwards or to the rcaI', though
pnKluaion. ModifiG.ltions kept lx:ing introduced. downwards view is slightly limited by the long
When protOlypcs 02 and 03 resumed flying, respec ;wionics bays.
tively in Novcmber and December 1978, the)' in Theonly m<tiorsetback in theprogrammecamcin
corporated thc Mod 2 package which indudl..>d all Novemher 1980 when 04 wasdestroyed in a mid·air
wiring for the mission avionics (though tbe vital collision in no way due to allY fault in the helicopter.
scnsors had still not been selected). Completely new This machine had just completed a programmc of
3viollic;bayswcrcconstructed,startingIleal'Ihe nose weapon ltials using all planllcd types of armament,
and extending back under the wing. enclos.illg lhe and 02 alld 06 cominued the work using Ihe Pilot's
upperp:.lrt 01"each main gearon the wa)'. Night Vision S)"Stem (P:'\lVS) in an important selics
Even more obvious W.IS continuing uncel1ainty of night filings.
O\'erthe horizomaltail. The fixed T-tail wassatisfac President Rcag<m signed the FY82 (Fiscal Year
tory in most conditions, btU at extremely 10\\' level 1982) Defense Bill on 19 December 1981 in which
so-Gllk,,1 NOE (nap of the E.al1h) flying-it let the was an item for $537.5 million for the first II
tail sink d()\\'n and the llOSC point skywards, deman production Apachc..'S. Hughes announn.·d plans to
ding major forward stick movements at times when build an assembly plalll on a virgin sitc at MeS<I,
cockpit workload was high in any case. AV03 Aew Alil.ona, and this openl.."tl in Februa'1' 1983. On ~-SO
with a low lailplane. but something close to the September 1983 PVOI, the first production.vehicle,
or
definitive tail was not seen Ullliithe first the new was rolled out.
2
Technical Features
T HE HEART of any helicopter is its rotor actua!ors between the pilot's scal ;:lIId the main
system, and (hatofthe Apacheisa C<'1refully gearbox. Following major h}'draulic failure the sys
considered blend oftradilional practiceand lem auton.latioll)'switches toSpcn)'secondal)'back
new technology. Though it has passed through im lip FBW (lly-by-wire) electrical signalling.
IXln:i11ll stages of modificltion, the main rotor h;:l'\ An unusual fealUre is that all major stresses are
always been full)" artl(."ulaled .mel had fnur bladt's of transmitted \'iaa fixed rotormast from thebottomof
relatively small diameter resulting in unusually high which the helicopter is hung ,'ia four (ubular \'ee
di5C loading (as in the small Hughes Cayusd struUi. Themaingearbox ishungunderthecentreof
Defender family). Eadl uf the four inlcrdlangeable the fixed mast and drives via a tubular shaft passing
bladl..'S h,l.." a bmad dl0n:1 and a highly Cl.mbered up the centre to the rotor hub spinning on roller
aerofoil st.'l.Uon. As nOlc:.'t1 pre"iously. the tips are bcarinb'S at the top of the fixed mast. This prO\ides
rak(.,,(] backwards to rtxlucc compressibilil)' problems dual redundant load paths. and allows the lr.msmis
011 the ad\·ancing blades. For transport by Glrgo sion to Ix:: rcmovl.-xi while kl..."Cping the rotorin place.
aira-afLcadl bladeam readilybe folded through 90<> No bearing lubrication is Ill."t.."(k-xi in the main rotor.
or remo\'c:."t.I aud stowed. and the intenlll.."diatc..: and tail-rotor gearboxes arc
Rotorbladestructure 80:10"·:Thanks10i~sheeTPOWeTtheApKhcis~k.Puttingon
Fullpo".""andslammingthecyclic,,"tid:ForwardFormaximum
ForwardsaccelerationputstheApacheinfOthisanirude.
Each blade has live parallel sp.1;r.s of high-strength
stainlesssteel,separated and linedbystmourallUhes
of glassfibre. Laminated skins of I,hin Sl;links.~ steel
are wrapped I1Hmd from the fronl., Ihe number of
laminations vel)' rapidly increasing ;1I the root to
form a solid stack ofretcmion straps through-bolted
together. The trailing portion of cach blade is of
compositehoneycornbstruUurebondedon separate
ly. TRE AclvilnCI...>d StruC!urcs Division were required
to demonst.rate sustained operatioll under the most
severe cOllditions with olle steel skin cracked across
and any aile spar ShOI through.
At the root the multiple laminates are allowed to
pivot upwards by <tn offscl flapping hinge, and to
nxk to fronl and rear in lhe plane of the disc by
c1astollll::li, Ica&1ag dampers. Anti-"ibration masses
are attached al from and rcar of eadl rOOI on the
leadllag tic rods. !)ildlchangesare introduced in lhe
usual way by n::nicaltie rods from the lIppe,- (rotat
ing) swashplmc, the non-rotating !o\,'er swashplate
being tilted according to lIight-eontrol input de
mands by three po\\'erful Parker Rertea hydraulic
9