Boeing Technical Report 0210105061/ October 1972Aerial Artillery Design StudyT\\lOExternallyMounted XM204Howitzersona CH-47CHelicopterPrepM'ed forAdva:'lCfJd Concepts DivisionAircraft Weapons Systems DirectorateWeapons laboratory, WECOMRockIsland, IllinoisContract DAAF03-72-C-OOt6;The Boeing Company, Vertol DivisionPhilach,lphia, Penr,sylvaniac~ - , .. -, 7''\. l ~ ItI. . - ~ . l .'. j \w,... .. i .... -.. 'Dlatrlbutlon of11'11,cIoaul'IIeftt II unllmJtecl.SecuritvCla..UlcaUonUnclassifiedDOCUMENT CONTROL DATA. R&D(S.eu.lI" elllle."o" 0' '111., t.od" 0' .b.'el ."d IndI", _"o,.rlon mu.r b "rd..."." ,,,. 0".'."I.elIII.dlAerial ArtilleryDesign Studv Two Externally-Mounted XM 204Howitzers on a CH-47CHelicopterS ... UTHORIII("'.........lddl.,"ItI.,.I..'"....) Altred HOnneLJ.-ueslgn; :s.:s. Ua.i.las-Yertormance.Robert P. Giantonio-Vibration/Oynamics; LeoGumienny-Integration; Edward H. Higgins-Stress Analysis; Norman I. Klavens-Muzzle Blast; Arthur MacArthur-Missions; A16ert B.Meyer-Aeroelasticity; HenryJ. Neeb-FlyingQualities; EnglishPiper-Fire Control;Richard R. Pruvn-Summarv: Richard O. Semole-Prooulsion; Maurice E. Snook-Wei2hts.DESCRIPTIVENOTEI ('TYpe 0' ,.po,' ."d l"du.I". d.')Twelve Part Final Report), REPORT TITLE1. ORIGINATINGACTIVITV(COlpo, u,"o.) z., REPORT.ECURITYCL.....,FIC ... TIONThe Boeing Company, Vertol Division UnclassifiedPhiladelphia, Pennsylvania 19142NoneiI .I I:!IfII, CONTRACTORGRA.. T NO. , ORIGIN... TORSRPORTNUM"ERlS!DAAF03-72-C-OOI610. PROJECTNO.0210-10506-1e.lib. OTHERREPORTNOCSI(An" 0'''.' numbo,,,., ..." h'In.d,,,,. repo.,)d. NoneIll. OISTRIBUTIONSTATEMENTDistributionof this document is unlimited.1\. SUPPLEMENT... RYNOTES 12. SPONSONINGMILIT"'RYACTIVIT'NoneUnitedStates ArmyWeapons ConunandRock Island, Ill. 6120111. AB.TR"'C TDesign arrangement and mounting approaches, weight estimates, balancecalculations, stress analyses, andhelicopter performancepredictionsof anaerial artillerysystemutiliZing two externally-mounted I05mrnXM204 soft recoilon a CH-47CChinook helicopter are pre-sented. This design provides for all the firingmodes andoperationalcapabilities required by the Weapons Command, including theabilitytooffloadone howitzer when the helicopter is hovering. The study in-cludes an analysis of the structural integrationof the weapons andaircraft includingmuzzle blast effects and airframe dynamic responses.Aminimumadequate fire control systemfor air-to-groundfiring andtypical groundartilleryfire control equipment was included. Missioncapabilities of this systeminclude deliveryof rounds of rapidair-to-groundfiringat themidpoint of a lOO-nautical-mile radiuswith 15 minutes loiter to acquire the target. Deliveryof a howitzerfor detachedfiring and a mission usingthe aerial artilleryforattachedfiring were alsoconsidered. Model testingthat demonstratedthe feasibilityof model Lng the l05rnrn howitzer for muzzle blast effectswas also included./- AUnclassifiedSecurityCI8IIsificalionUnclassified....... -'-UIlCl ...1f1ed....On.'" III I-b,.I.INKA I.'NKC llEYWORO'ItO\.. WT 1t01.. WT 1t0L.. WTAerialArtilleryXM204 HowitzerCH-47CChinookHelia.pter,IFireControl'-',.,. Blast andFlashSoft RecoilAttackHelicopterAirborne lOSmmHowitar:'lodel Blast Testing". ,,-....,. ..-...- ...Contract DAAF03-72-C-0016BoeingTechnical Report 0210-10506-1October 1972AERIALARTILLERYDESIGN STUDYTWO EXTERNALLY MOUNTED XM204 HOWITZERSON ACH-47C HELICOPTER'. ... DESIGN PAYLOAD- ,- 8 t1\5 G)('" I-

co.... 4 I---+--If--+--+--+---+--l---+--j.- - (") ""'r:S-0:;:) 0 fP ;..4 .,. .I--+--+--+-+-I-+--+--+--+--z.,r'"o---.4.-""'--I.......r.--I..-............. .......,.o 20Figure 43. Capabilityof Aerial ArtilleryCH-47C onDetachable Howitzer Missionat 2,000 Feet,95F89-WARMUP 2 MIN ATNRPCRUISE OUT AT 99% BRSHOVER 'OGE)15 MIN AT STATIONFIRE 60 ROUNDS OF AMMO (2,220 LB)AND SAVE AMMOCASINGS (157LB)- NET 2,063 LBCRUISE BACK AT 99% BRSLAND WITH10% FUEL RES[RVE24,796 LB EMPTY WEIGHT689 LB FIXED USEFULLOAD7,004 LB FUEL TANK CAPACITY- 3,751LB - REMOVABLEHOWITZER1,600 LB- (2)CANS OFAMMO1,000 LB - (5) GUNNERS3,200 LB - PERMANENT HOWITZER2,200 LB- 60 ROUNDS OFAMMO800 LB- (4)GUNNERS12,571LB - DESIGN PAYLOADVERTICALLANDING CAPABILITY(41,750 LB)AT MISSION MID-POINTTAKE-OFF GROSS WEIGHT46,000 LB (MAXIMUM)45,060 LB (DES PAYLOAD/FULLFUEL)(41,750 LB)(VTO AT 2,000 FT, 95F)20 40 60 80 100 120 140RADIUS - NAUT MILES.-. " . . ~... _ ~"""".V~/f;......--'.., ....""""."""".~V ~' .....ro...~ .... ~....-:::"""".V...... ... ..--- :;,./ '--r-- --~---~ -,-- ::..0'"1 -e--r-- 1\ DESIGN PAYLOAD-r--4~(") c::.(;)- "P- ~V ~ "0 "'"(' 0~\~~o2::;)oCX)I-::;)o24a3..J8. 20..Figure 44. Capabilityof Aerial ArtilleryCH-47C onAir-to-GroundFiringMission at 2,000 Feet,95F90VERTICALLANDING CAPABILITY(41,750 LB)AT MISSION MID-POINTj1i1I1IjI 3,751LB- REMOVABLEHOWITZER1,600 LB- (21 CANS OFAMMOTAKE-OFFGROSS WEIGHT46,000 LB (MAXIMUM)45,060 LB (DES PAYLOAD/FUll FUEL)41,750 LB (VTO AT 2.000 FT, 9SoF)Fig1Jre 45. Capabili ty of Aerial Artillery CII-47ConGround-to-Ground Attached-Firing Missionat 2,000 Fect, 95FWARMUP 2 MIN ATNRPCRUISE OUTAT99% BRSLAND AT 5TATlON AND STOPENGI NESFIRE (2) CANS OFAMMO (36 ROUNDS)FROM PERMANENT MOUNTED GUN -1.600 LB TOTALWARMUP 2 AT NRPAT 99% BRSLAND WITHlOOkFUEL RE:SERVE_24,796 LB EMPTY WEIGHT689 LB FIXED USEFULLOAD7,004LB FUEL TANK CAPACITY9124 p----r--"---,-'I-,-rl ' i I I IIi! 1 l ---+--. -J -- i _..- - ..--t--i---,jm :: Iii; I:I...I..J--i---r--'-+::; .-:.1g :;LsI/' X NORMALPOWER.03........,;,-.-.;40000 46000.05wt.:lZC(a:u

uw55! -t100 120 140 160 180TRU[ AIRSPEED KNOTS103CH-47CHelicopter Specific RangeAirspeed.02 L..-_......__"""'-__ ....I80Figure 53.r,---!i,;"1i1j1J14828 32 36 40GROSS WEIGHT 1000 LB24. I .CH-47C Helicopter Specific Range andCruiseSpeed VersusWeight.0220SEA I.EVEL/STO ATMOS. TWO T65.L.11ENGINESNOTE: 235 RPM (BELOW 40000 La) &245 RPM (ABOVE 40000 LB). -1'-..... ()(MSN -,--:'l ' '. ! . .r' . ... L,,,,,,.,.,. I .: .. -1' , . . I ' ,,, :140 . ... ;..+....1.. ';..... _-L--;-.otf--1...,..-; (XMS Vi i:n-..

_...,.1 . 2:!...-. I t I. a::100 'H-- - -- .STRUCTURALENVELOPE t.1':..--. -.-I NORMAL POWER ...: - - --- 99% BEST RANGE -.-(80 I I ! . I 20 24 28 32 36 40 44 48.07 i ; I 1 J ,.__.. '''1 . . '+--+--+--1.. i;, '" Ii!: A RD I I I.06H-t--iI ST NDA I+-' I.... ;....;. I .'. : I I ." I --": :. ; ZOS. ._- +.. _ :1"':-0 __I I ,,, .! -.....J '-'" '"'1 . +1:'..... CiS,-. "-t-";;t ::::r' .-;.--:- ....; " I I wI........ I.. :..Q.04 i ! .... .. I..1.--ARTA'IEl.REIRAVL'''; I. : !"', 4.. . . \ . .; ,a:.03 ...... _-. , CONFIG ',. : I, 1 , W.. ' '.' 1"11'-II ! t-o --.- __ 1 ..I'! i II II C!i

CwwIsa:1)U1t. Designcondition #15, Table XIVPz=ex 3570x .5 =14300tbs fbz=M =14300 x50 ; 124000 PsiZxx ~ . 8FwdBeamAnalysisUlt. Designcm dition #8, Table XIVPx- =1.. 5 x 36500 x .4 =22000 Lbs.fb=M =22000 x 50 = 22000 Psix -Zzz 50M.S. =166 -1 =:22M.S. - +6.55Aft BeamAnalylli l z(Fwd)x_ ... -,Hx \!-tyPy'y (Side)E:Fz+ 0Pz1+ Pz2 =16,800 lb = 049 Pz2 -Pzl = 0P== 105 pz2 49 zlPz2:::2.15Pzl11>z2+Pz2:::16,800'2.15Pz;t::::16,800L 465Pz2::::11,500 1bPzl:::5,300 Ib163-"..::";.-.;- .., .... - ..-.. ". --'",;.,-..-...._... -. 102"40" _ 30"i-Ao;B .----B'---'---:.. ';'--- . ' 300; i __'\ I1 t ,1'z2= 11500 Lbs. ofShiFRaz - RBZ-64" .-,... ..J.. _... _.... --- ---_....__. _.-,.iI'!

Dr-121",--RDz-:FZ::aRDZ;;11, SOD 1bcMox;;0-30 x U500- 21 x 11500 - 40 RBZ+ 104 Raz= 064 Raz=51 x 1150064RBZ= 9,200 1bCheck- 51 x 11500 + 64 x 9200 :: 0\:MZX:: 0- 51 y 11500Ii.II.Jo =0 :. OK70 x 9200 + 134 x 9200=0164...... ... """ ... i;,,& ........ _ .. _,.__... c ....,.,., """"' ......... ___ , .....-.... A-ARequired Sectionpage)Hoist StructureMaterialPlasticBcndinqat sectionA-Athe X Axiszb = 6"--t-,,-B =6"ti t=.064"--Hx-.L--B r--7075-T6 Al. (CLAD)Propert i.esFtu=73 K5ir ty== 63 K5iFsu= 44 KsiE = 10.5 x 106Psi= 115000 ps i;: 1.5165;::;; 30 x 11500ZRP.cqu iredfor KZR;: j' Pz2= 115 K5i );: 84 KsiFb".l- -ZR = 30 x usoe'---rTs CJ 003 O 3ZR -- Ln.'AssutT,ed Sect ionFbu = rlcIXwhereh. IbH8IxZxAreaAABH3 - bhi= = 1.5 1ZRr-1S = Zx - 1!-1S = 0.0Vertical Support Member, Section B-B Allowable Stress Pc;-={L ' /. FColumn End FixltyCoefficientC =4Asume Section same as Section A-AL' =L =90 in..064".-hI

H''-li., = 2.45 in.Pi a:::determine:::5.23 :::16,470:::240:::11 x 10" (1. 58X101\ psf):::59,000= 39,000:::143,60U:::143,600 psi-.'4.. A.. .&.staticyield strength, psistaticultimate strength, psiC thickMSS (doubler)l - densityC-speed of sound, flsVc- cri tical velocity, flsE elastic mOQu1us, psi:: +S.8S90=2:T5371672024-T3 AluminumAlloy (CLAD)dynamic yield strength, at'.Ie' psiCV= 5.23 x 16470 x 240I e -- 144Material1'15Fc= 52.5 ksif cRDZ 115007,670 psieA:::--r:"5'=Fc -1 52500-1 =(c:::7670FromSDMFigure 4.1.2.1-6 (Reference 15)L'/.,The zone 8 charge is based on an inflight malfunction as showninTable XII. The aft fuselagewill be protectedduring groundf iring by limi bng the azir.1Uth tnvel. Prt!sent CH-47C forwardfuselage skin thicknesses are sbown on the following page.FUSELAGE SKIN DOUBLERSIZE DUE TO GUN BLAST PRESSURE WAVEThe purpose of this analysls is to determine the forward laqe skindoubler sizes requireddue to a gUll blast at zonE' 8charge.JII....Iolo_

,..__.,.-_,_oIl>.-l

"..'-.._1.Y>..lIoo..t.....rr-wherep12.0 psib =iO in.a = 5 in.169--- b ---,[J-_L-i-Po =ambierit pressure=14.7 psiThe critical time (te) is the durationthe yield pressure mustact toottainsufficient impulse toyield the structure. Thecritical structure Of.CII-47Cis a panel normal to thehowitzer pressure blast.Pr = 2P"JPo + P(7 x14.7+ :. 4.04Pfi (Max. Allo'."ab12 free-space overpres-____ -- sure for present skin)RcquiradDun azimuth position toprevent anof thoafCsturb' d fusdag0 skin 1S; :: 1500Max. aft fuselagesupportr- '" \oo... -_ .. ".'--' .-; . - 180(\ Fwd _.,1--'" ._ -.- 1. _PIJl..TFORH; . -------------,--......:.....:---..------.-- ce:-J;_.....--.....,

LAA'vJS-CH-47C171tl.....-..-- ____.'._ ......,ESCAPE BATCH::'T,EXTGLAS DOUBLER AN;"LYS ISDrawinq Ko. 1148-2721Material Properties fromLockheed Stress Memo No. 124.Sa :: 3,160 psi (test sUbstantiat0d under static loading)PUol l::scape hatch d00r strength al; Getermincdfromtests atDrawing1145-1713. Pane was loaded withoutfailure to 1.2psi,172II1ij1IJ;1jjIj1,1ension ist ::: .187 in.246 (Reference ?l)E..J.i:. = 1. 219 'I "Et4.5 x 10 x .18719.- _-----: L--- I.I .: . 12:itL.Ftu:::10.3 ksiFeu= 17.0ksiFLu:;:16 ksiFsu= 9.0 ksi- .0:':; Ib/in.:FUA= 2/3 x 10300 - 6,900 psiCoef. =l< :;:Plexiglas :1 SolidE - 4.5 xpsir ". (Poi.3son' S ratiu)k ::: 284Sub.'- ::: 72.5EtEt'Sa=72.S--b:The ultimate allowable designstressFromRoark, Pg.r..CIIIIlAIIII .'.tIlll4Ql'IliIlll4...1III ..!!!Z.....I!Q;;;;a_# ...... ,.W\i4""Slll'. .,,17J\'/1= 20.9 psi"'ave= 17.0psiw2=15.3 psix 25.5 x 10.54 x 2 x 6900- 21.0 india= /3x 2S.S x 10.S4 x 2 x 31fiO= I 3x Pu x r'4x l'u(all) dyn.tt - .39 in.tr =10.S in.PI. - 17 psi (limit)t ::: .58 in.Fu (a 11) ::: 6, o,IFigure 79. Comparison of Predicted and Model OverpressureMeasurements at 20 Calibers Off Boresight UsingProjectiles With Reduced2021iI1l,17 14203CHARGEWEIGHT GRAINSIIIi61----+-__ ---lI -----j\ .I8t---+LEGEND-EXPECTED TEST DATA USING SWRI"PANCAKE" TRANSDUCER NO. 14910DOUBLER PLOT POINT 12--......-----,------,..-----;r------..,------,(/)c.!wa:::>(/)(/)wa:c.a:w>oFigure 80. comparisonof Predicted and Model OverpressureMeasurements at 10 Calibers Off Poresightrf ':".1. ". _ ..;. . ..;,. :- . _ .."-_..... "'-"':..-:-....-:.-.LEGEND----+----18r------r----------------,

%ClViu.Iex: 6 ...---.---.+-+-------oco

oenc:u.ICI) 4-'

FWD ROTORG.. ---yThe net increase inhover downloadof the aerial artilleryconfigurationover the standardconfigurationCH-47Cissummarized below:Ref.AV.'..1wCI>v

;; A.Area (sq. in. ) (in. ) (ft. ) %R K (%)Al1170 65 1.5 .80 14.0()45 .0732.5 45A28496 204 3.5 1. 20 32.5 45 410 2.2889.0 455Total (DL; for Removable Howitzer 2.311T .(3) Reference: "FluidDynamic Drag", SighardF. Hoerner,1965Removable HowitzerNOTES:(2).43 added toref. area, Al to account for extendedplatform, A2, influence on vertical drag of adjacentfuselage(1) Reference: "Technology InstructionManual", W.B. PeckandC.B. Fay, Boeing-Vertol DivisionPe rmanent Howitzer Ins tallation:--let I ncreasc Over Cit - 47CRernO'lab 1e Howi tze r InstallationHover "DOW!: load(Percent of Total Hotor Thrust)

2 .355.25.,"2212.90}!l;FCD Ie--Projected Based On Equi valentFrc.ntal Projected Flat PlateComponent Quan t.i ty .h.rea Frontal Interference Drag Area(ft." Factor (ft-'Gun proper. 1 14.58.8(1)1.25 14.6Platformand Loader'.1 8.121.2(2)---- 9.7supportBeamTotal',fefor Permanent Howitzer 24 , '3Permanent HowitzerAn estimate of the increase in equivalent drag area (fe) of theaerial artillery aircraft overstandard CH-47Chellcopteris presentedDRAG AREA_-- ..J _'"",,---,---,--,,- '".. ", ','" ", ,._',,,.Removable HowitzerComponent QuantityFProJecteFrontalArea(ft2)D .Based On IProjectedFrontal IArea E i 1 .--1qUlva ent ;Flat Plate :IDrag Anila(ft2)!I.816.1.8(1).4 (2)1.2(2)B. 431.9020.10211I 20.2 II II I\'iinch Support 2 6.16 1.2(2) i 14.8 JBeams (Fwd & IAft) I ITotalfor Removable Howltzer 51.9jGun proper,IIRetractedGunh'Jhee 1 &Axle I. !\!>lain SupportBeams (Fwd &!Aft)NOTES:( 1) Reference: NACAMerna No. 1-3159L, "Parasi teDragMeasure-ments of Helicopter Rotor Hubs", G.E. Churcilill & R.D.Harrington, Feb 1959(2) Reference "FluidDynamic Drag", Si