XXI Bomber Command, Monthy Activity Report 1 May 1945

8/6/2019 XXI Bomber Command, Monthy Activity Report 1 May 1945

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C l a s si1 o a t i o n o a n o e l l e d b~aIP~ .w m :Q~m ~ ... 2 . o . o . . li..

1 MAY 1945

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TO"-YOllR/!>IIN,~AR.5e""IL !IN'E-II:;13 -IS II"R!Lcc e s TONS 15_5 'tURE 5Q JYI/Lt'S

XX I BOMBER COMMANDI-I IG HL IG HTS FO R APR IL

HOPAGA'YA CHEMICAL INDUSTRy12 APRILUJ4 r.:;/Vs 59% DAM"'NO

KORI t'AMA CHEMICAL PLANTIZ APRIl.171! ,.:;",5 73{o J OAMAGEfJ

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XXI T IOMDER CQMlIu U ID

M 0 li T T H L 'Y ;,. 0 T I V I T Y R ~ l' 0 R ~.5 M a y 1 9 45

PART 1 STREN G TH O F THE OO M lil.li.1 :IDP .A RT I I USE O F A IRC lW 'T . . u r o ORE1'lSPA RT III M AU lTENA U CE A S IT AFFECTS U SE O F A IRCRA FTP.A ttT IV EFFECTIVlll~SS O F A IRCRA FT 0 11 M ISSIO NSPilRT V RESULTSP iIRT VI CO ST O F IwIISSIONSPART VII APPENDIX

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Prepared By33rd Stati.sticaJ, Control Ul).it


4/13

PARTI - STRENGTHr THECOMl-'tillID1. Movement of units

All lL'1.its assi5!led or attached to Ma.C.quartors )0(1 DomberConunandand the 73rd, 3l3th and 3l4th l30mbardmentlTings have nowarriv-ed in the Theater, with the exception of the 680th Jomb Squadron sche-duled to reach Tinia.n in June and the 509th COQPosite Group in July,~'1.dthe 327th and 890th Chemical Companies scheduled to roach Guam in~ ~d June. All flight echelons of the 5Sth ''ling are now in thethea1;er or enr ouuo , but the movement of [:;ro~'"l.dersonnel \till not becomy:>leteduntil June. Grounq,personnel of two bomb and two servicegroups and UiI16Hoadquarters of the 315th lTi;:J.garo no", in place. withmovement of personnel scheduled for completion "u y 30 June. The 347thService Group is now at Iwo JiI:l8, ',,1th the 348th Sen-iQa Group s~duled to arrive about 18 l'f.ay. . .2. Personnel Streng!h

.li.t the end of the Llont~ the strength of the Comnandin thetheater was 6915 officers and 36407 enlisted men, or a total of 43322compared to an ultimate strength of about 65.000. ;.3 . Aircraft and C~ewStrength

. A s of 1 May, the Commandhad 616 aircraft and 770 cr-ews,compared to 482 ai:rc:C[lft and 619 czevs as of 1 .April and a projectedstrength of lOo~yery heavy aircraft and 1070 crews on 1 Novomber.It should be noted that this projected strength, which is based on ,latest availa"u',e flow date, actually indicates a smaller number ofcrewa than aircre..f't. This is considerably different frol!l the two crewsper aSSigned aircraft ratio requosted. This ratio for 1 May ';/as onl.Y1.2 to 1. Act.ual ,aircraft and crew str ongbh for 1 l~ 'Wa",about 10%less than that anticip~tGd from il~ormation received at 1 April.1 Mevcre,'T strength eJtpressed 1n terms of potential sorties(baaed on a 35 mission -:;our and 1 \ , 2 % l,ocs x'ute...-see the study ~o~_tial Sorties and Cre'l'IRotation, II dated 5 May1945) was 13,792 comy:>aredto 12,724'for the pravious l!lonth. However, this was an average of 19.5potential sorties per cr~w cOl!ll!landercompared to 21.3 for 1 April.Potential sortie il1vento:,:iOs still gave indication of droppi~ sharplyupon the beginning of rotation. '. ~e 73rd UiI16at 1 M a showed a . dis-proportionately large percentage of its crews \Tith 16-21. credit sorties.!he' 3l3th Uing sLo\lsd an even le.rger' percentage of its crews in'the10-15 credit sortie class. In part due to their short time in thetheater, the 3l4th Wi~ as yet has shown no leve1i~ out in its Bortisexperience. Leveling. of course, is necessary to prevent large out-flows in short periods with consequent inventorY decreases. Obviou81ythe present uneven flow 'of replacements tugether with crew shortagesand maximumeffort conditions make difficult the use of much discretionin select'ing which crews will fly particular missions. It is clear,however that tha present rate of operations cannot 00 maintained for~long t'erm period. unless the ratio of craus to Aircraft is raised andthe ere",,,credit sortie e:..-pe~iance.1,3VE'le4to Pf~V'9m C\{sprQp,o;'t1onate.,.

ly large outtlawC of crews for rotation.

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5/13

r~r{:_II. USE OF B-29 A IRCRA F'T A ND CHEWS1. Hours 7lo:;n Per B-29 Aircraft and Crews

Hours flown per aircraft and crew decreased llligh'tly inApril from the .March r'ecorde , As shown in the tablf; at the botrtomof the page, 1 0"i. 0 hours -wereflown per assigned. aircl'l',ft\luring the month compar-ed t.o114.9 hOUl'S (1.uring March. Theplanned figure Vlas no. Ex-cluding aircraft andt.ime ofthe 5 8 t . h BombW i r J g , which wasn o t scheduled for operationsbut flew :i,t~ own aircraft thelast few days of' the month,the April f.igure was iD8. 51 0% of .il.pril flying time wasutilized I'oi: training purposescompared to 9% in ~~arch, 21%in February l : . . n c l 1 7 % in Jan-uary.

A ccmparison of20 wings shows tho 314th Wingw-ith 115.2 hours pel' afr er-af't.,

the 73rd lUng with U,.l andthe 313th' with 100.1. Theo Im;rc.;r utiliz&.tion rate of the_;n::th hing is confirmed by alower sorti~ rate (see below).Thi" .faS caused in part b~ thefaot that the 313th Wing had an average of 64% of it.s a.ircrdt out of .comarssaon during the month compared t.o 40% for t.he '73rct ~vi:r'i5 and 38%for the 314th Wing. Thi~ was largely l'efler:ted in greater time outfor engine change & mai.ntcnance and for Lnspec td.on, 'l'he 313th pulled

248 engines during the month compared t.o a~for the 73r:dWi!;lgand9.3 1 0 ' " the ,,14th fling. Ths disproportlo.natf> n1.Illl:bcrof pul.Ls forthe .3~th -;'lirilfwus ;Ut:r.gelydue to su st Je c :t 'o .: ltblow--by!;f).

! J ; ; ; , G hours per .:a;jblgned crew were flown by the CommandinApril compared to 86.1+ hours in March. Even the lower april 'figure washighc,:c than the 60 hour planning f'Lgure prescribed for long term util-ization of creW6. It is c10~r t~at the only way to reduce these ex-cessive hours is to increase: inuneC:iately the rs,tio of crews to air--craft. The seriOU5l1SS of t.hc cr-ew pr-ob.Lom is clearly shown by thetact that tho JUth \7ing flew r.n aver-age of


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2. Sorties Per Aircraft and CrewS O R T I E S S O R T I E S P E R C R E W6~----------~~------~

543

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utilization of aircraft and cr8WS expressed in terms of so:rtiesalso showed a slight decr-ease , Th e Command avera..ed 6.8 sorties per as-signed aircraft in April compared to '7.0 in March, am 5.;3 sorties perassigned crew both months. The 73rd Wing achieved a record high of 7.9sort ies p er aircraft and 5~7 sort ies p er crew compared to the March highsof 7.4 am 5.5.

3 . Other Uses of Aircraft90 B-29 aircraft were airborne on weather strike missions dl.U'-

i11g April compared to 89 i n March ard a to::'aJ. of 405 to dat,e , 91% wereeffective compared t o 94% for the previous month. Mechanical failurewas t he sole reason for fai).l.U'eo complet e these missions.

78 B-29 and F-13 aircraft were airborne during the month Oftp hot o req onna. issance and I ':adarscop e missions com pared t o loo sort ies forMarch. This decrease was caused by less radar scope missions. 7 6 % oft he r ec on na is sa nc e f li gh ts ani 100% of the radar scope flighojs were ef..fective as compared to 73% and 92% in March. With the arrival of the1st Photo Reconnaissance Sq at the end of April, it was expected that thenunber of photo sorties would be increased for the next few months.

Other uses of aircraft for April showed 39 B-29 aircraft es-cort ins t ight er p lanes for nav igat ional nnd rescu e aid, and five seaaearch aissions.

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7/13

PART III. tM IlITEN I\NCE AS IT AFFEr.TS USI: OF A IRCRA fl'The continuation of the high utilization of aircraft during

AprU, previously discussed, is i tsclf evidence of maintenance effici-eocy. In addition, the aircraft abort rate did not increase but remain-e d substantially unchanged (See part I V ) . Still another factor was thatthis utilization was maintained despite an increase in the aircraftd a m a g e rate to 17.1% of aircra.ft bombing compared to 8.9% for March.And further, the percent of airborne ail'crE..ft which abortt:d for mechan-ienl reasons continued its stet'.dy decline. As shown in the chart belowtthis perl!cntage w a s nt>wonly 4.6%, a decraase of 14.4% since the 'begin-ning of major operations to the Japanese main] am.

The percent of aes Igned aircraft non-operational awaiting partsreached a record low ,of 1 .3% in Apr.n compared to 4 .2% in March and 4.5%% O F A I R B O R N E A l c ABORTING in February Despite this how-FO R 'MECHANICAL REASONS . ,20 0 ever, an-anlyafs of stock levels (see "Six Months Projection ofCombat Effort and Logistical R e -quiz-ement s , dated 15 April) re-. 15 veals that operations may be

12.3 seriously hfrder-ed in the nearfuture unless required stock10 levels are immediately establish-0d to take care of the increasedcombat effort.

5 The supply of engines,however , ,/ill be sufficient toraeet our increased operationaltempo at least through the monthof Septomber, 1945. The engine

'-'=':~--=';;;":_-L~':":':"..1-'::"=':;_L.....;=~_.:.;AP;:..R~ requirements have been followedmonthly and this projection ofeng.Lne limlls is based upon thepast exper-Lencc of this Command . The shipments O f these engines are

set up to pr ovfde a maximum Leve I of 60 days spares on halXi and a mini-mumof approximately 45 days spares on hand. As of' 30 April the averagehours on pulled engines .was 256, compar-ee t-, an E:.i}'t:ctbdLd.f'e of ;300-J20 hr s ,

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R-3350 SPARB ENGINE REQUIR.Em;NTS AI~D S H I P M J . i ] N T SGHEDULESIitA,! IUUE JU LY A U G SEn OCT JQYSpare Engineson Ham* 1508 1247 1555 1662 1937Estimated ~nginePulls 917 992 1093 1225 1452Engines Scheduled

for Del1verY'** 65 6 ~O O 1200 1500 1300Engine Shipment1376equirements*** 750 1169 1452 1408

Plus or Minus -94 T l . 3 1 -252 1"92 -76

1785l408 1376 8463

59561431 1404 8990: -199* Estimated Spare Servic6able ~ngincJ on Hand as of 1st of each month.** Actual Shipments committed to this command.*** Requirements based on I:) flying hour's per average assigned aircraft

on hand per month.Another factor which gives every evidence of critically hinde~-

ing the combat effort of the Commandwas tho gr-owfng maintenance backlogat tbe GuamAir Depot. Dur-Lng the month this backlog grew from .11 B-:?9aircraft to 18 B-29 ai::-craft. ~}..ncethe c.:ommarribegan ope:rations Lasr tOctober, th~ output of the depot has only been 18 B-29 aircraft, I1Ld 3of th~se were returned to the Unit;3d states am 3 were salvaged. Atthe em of the month, the average, B-29 aircraft on hard at the D2f.-otha,'. been there for l-~ days.

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8/13

PARTIV. EFFECTIVENESSOF AIRCRAFI'ONMISSlOR)1.

100 100 I80 8060 604 0 40 -20 20

0 0

The percent of airborne aircraft bombingprimary and anytarcets was approximately the same for the Commani for April as March.8 4 . 6 % bombedthe primary in April compared to 84.5% in March, am93.1% bombed an;v target in both months. The 73rd Wing had the highestpercentages and the 313th Wing the lowest, as shownin the abovegraphs.

2. Causes tor NotrEttectivenessCauses for aborts were al. .s,~ 's'ul,)!Stantially the s8ll\e 1n AprU

as in March. 7.~ of airborne aircraft were non-effective comparedto 6.~ for March and 12.5% for febl'\lB.fY,. a.rch ani April a~8break downas follows:

M!rh AprilMechanical Failures - Engine . 3 . 0 % 3.1%Mechanical Failures - Other 1 .6% 1 . 6 %Fault;r or lnadeqWlte Maintenance 1.2% l.~Inspection b .r Ground CrewsPersonnel Failure of Air Crews O.~ 0 . 6 %Ualmownam other Qd4 ~

Total 6 . 9 % 7 . 0 %

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9/13

1. Destruction e X _ Tn.T...T:.f.During the mon+h the t' .v \J o"wa :1 " P "'daylight c.ttn.cks against j.ndl' . _ - c t - - ~ - ~ ' _ , p:~ormed four n.i.gl:.t.am sevenk va uaJ ",'I Jl'l",' t tattac s ngal.nst urban Elre"'s and f' :1- -:". . ..... nrge 5, three n~.ght h" C '-'


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.tt h LiS &withinl OOO f?let of an A .p. L s not__~ f h ~ 0 apnlicablo Cwas we.ue 0 eac .I. orl"lationl G 1:>omhpl~tt + onsequently, an annlysisactual IIPI from the assirmri ;.!PI. It ~o ~5certa1n the deYia.tion of thethe menn range error was "/00 "'('f>" "1 S oun:l that for 38 f'~;Cin'".I. ". ong" w ' U ~ , < : 0 . . . . "average d1stEtnce "snor-t or '" - n~I' fr 11 . e the ubsolute :':'(l{:"''o 0;1'1'')1' (the ' ,-c ve, o m th'" n . ~'the absolute defloc:t:ton e:r:'G'c h~' ' . : J t:G::.t.

At the present ,time, t:lO uv . .liable cOIIIp.:.risonof bombing ,j,('CilrUc a~Llble datI;!.. does not p~rmit any 1'e-that tbe recently adopt(ld stamnrd b;m:~~ ~~u w~ngs. It is hoped, however,comparisons in the n8",1' future. I ott.lng procedure will allow such

.3. Bombe.nd Fuel DntnDue h..rgely to hrgher bombing clti tudetancelS, th e average bomb load for the C r mm xi . s am slightly longer dis-poUDds from thu Murch record of 1') 295 ) m~ r ?~nd A~Z:il decrl3used to 11,5.22the 31Jth W'ing 12,088 pounds, l l .nJ. . . .the 3~14th~,.;rl'ng1' (i{~tnghv.v(;rdn~ed 12,880 pounds ,r di .II W~ un a J ustment of J O O Opounds or stance differenticl) aver",yed 12 0 7 . '1 . . I f'1 057 12 906 nd 11 66 .. . ""b I '+ aarc 1 .agures had beenJ, , , a J 5, resl,8cb vdy. Hence the. 31' th Winghad be bleW increas.: its avera&e 10r:.


11/13

( I I I. fAR, VI. CQST OF }IUSSIQi i1. A,1rcraft aM e rewLOise! ' ",Aircraft and ...crewloss r a t e s il'lC~eased in A p r i l am. for thefirst tialo, more crews were lost during a .month than aircraft. 'fhe a1r-craf't 108s Tate was 17 . 3% of U.E. C o m p a r e d to 14 . 3% last month ani an a . planning factor of 16%. The br~w loss rate W"'S 19 3"" f U EAIU" ref 1 t h ... /0 0 " COIII-pared to ll."i./O as mont am an AAF planning factor of 15%. The eub-stantial increas~ in crew l~sses was dUe in large p81~ to reclassifica-tion a . o o reorgall1zation of l.rxliv1duel crew members, hospitalization,an:l transfers to staff positions. 'E;_xpressedon a SO~t.i6 basie J '1 .6% of airborne aircraft we~e~Q!lt

compared t .~ l"?%' imJ~rCh, 3.~% ~l? Febr~.an::l 5.S%tn;.ja~:"


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t + > . . . . + > II! .p~ kc IJ 0 l!'I 00 8.-4 l!'I . . . . . l!'I 0.....0 .g C \J 0'1 . : : : t 1..0 Il\H 00 t- '-0 l!'I'!j t


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R~ G)~ ~ f ~ ~ ~(t ~ ~ ~ ~~~0 tor 4od~I~"

Documents

XXI Bomber Command, Monthy Activity Report 1 May 1945