21st Bomber Command Tactical Mission Report 47

8/6/2019 21st Bomber Command Tactical Mission Report 47

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M I S S I O N N O . 1 " 7F t o W N . 2 7 M A R 1 9 4 5

G O P Y N O . - : J


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No feature of this reportmay be reproduced or dls-. .seminated wi thout pr1.orapproval of Head.quartersTwentieth 4fr Force,.

This report is the firl5t

m:l,ne-laying operatlonllo r the 31~th Bombardm.entW ing, X lC I Bomber OQmmand.


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Field Order No. 16 Misaion N o . 47313th Bolli~rdl!lent Wing

l I E A D Q U A R T E R SX X I B O M B sa C O M M A N D~O 234

T;;'OTICALMISSION,REPORT

Target I Shim,ono!!eki Strai,ts & : Suo Nada27 Maroh 1945

Tabla of ContentsTa,etioe.1 Narrative . . , . Page No.1Annex A ~ Operation!! 9Exhibit ~ Track Chart 0 0 10

Part I .. NIl."11gll.tion 0 0 11Part II '" Mining 0 1.2Section;" .. Mining Result!! 1.2Section B .. Chll.rts Showing MineLocation 00 0 17 .. 21Section C .. Code Designation of Yi'nesand MIne Operll,tion 28

SeotiQn b .. Minelaying Pr-ccedur e " 30Section E .. MIne Handling and I,o,ndingo 34Part III .. Flight Engineering 0 43Part IV .. Radar '. .' 44Part V .. Gunnery 0 45Part VI .. ~ar ..SeCi.Rescue Chart 46

- w e . ather ."..,.............. II Part I~enther Swnnnry Part II' .. Forecast Weather vs Observed Weather.Par t I I I .. Prognost Ie M ap Part IV .. Synoptic Mnp 0 .'

Annex C ..Communio(ltlons Part I..Radar Counter Mensures 0 'Part I I ~ Rndl0 ' ! ! I ' " . .

.Annex D - Intelltgl)noe (See Annex A. Part II, Seotions Aa.nd B. for RESULTS) Part I - EnemyAir Oppo.sition Part II - Enemy .i>ntiaiNrai't

Annex E - Consolidnted Sta.tlsticnl Sumllll\l'Y~nnex F ~ X:q Bomber Oomlllo.ndDirective and

313th B6mbardm.ent Wing Field Ordar 0

. .Annex G ~ Distribution, . . . . .Prepared byI

A-2 Secti.onXXI Bomber Comrno.nd.

4748505 152535454

. . 56575861

. . '7leli


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::I:::I::::::::::I:::III ISEORET :B y ~uth. of tho C . G . :19 Ma . y 4S J :DG:

Initialrno.te: : : : : ~: , : : : : : : : : : I : : : : : t I

HE::.DQUARTERSX X I BOlliER C C l J . ! : M . J . N D

APO 23419 M ay 1945

SUBJECTI Report of Oporo.tions, 27 March 1945'1'0: Comanding General, Twentieth Air Foroe, 'Washington 25. D.O.

1. IPEN1IFIC4TION O F M I S S I O N .0.. On 23 J~nuc.ry 1945, tho X X I Bomber Commo.ndissued 0.

general directive to the 313th Bombardment 'Ving to prepare for mln.-lo.ying operations against area.s of inmedillte strategic and to.ctioo.1importo.nce to the enemw. On 11 March 1945, Il directive was issuedto tho Commanding Gsnernl. 313th Bombardment Wing. to initiate oper-o.tions,

b. Field Order Number 16, Headquarters 313th BombardmentWing. do.ted 25 Mo..rch1945, directed the 6th. 9th, 504th and 505thBOl:lbo.rdment Groups to conduct the initl1l1 mine-lo.ying operation ofthis Commo.ndon 27 Mllrch 1945.

c. Targets Specified;(1) Primqrv Arenp:

(Il) Shimonoseki erel;: Minefield Miko (Fgrge~ - Milln shipping channel through the western ent.ranceto Slum-onoaek i Stro.i ts wi th the grea.test mine density o.t turns in channelaround hino. Mo.tSur6. and Hiko Shima. nnd the outer portion ofWoko.mntsu Hnrbor; Minefield Milee (Foroe Bnker) .. Main shipping chann-al through the western nppro~ch to Shimono&ekl Ko.ikyo with grentestmine density in nr ea bet .....en Futnoi nnd Shira. Shimo.. and a.dditione.ldi stribut10q 1n Mitushima. Suldo. C\llchora.ga north of Yi'e.k!llMtsu, e. .ndthe area bo~nded by MurotBu Saki, Mutsure Sbimo., ~nd ~oken Saki,

(b) . l . ! . o , Nndll !..re91 MiMfield L o v e (For(le COOr11.)Ma.in shipping lane through Suo i No.de.with less dense minoflelds a.erossHime Shima. S\l.ido nnd the. are". between Hime Slrimo. a.nd the 01ty of B.ofu.This field was lo.ter extended to include 0. 11.00 of min.es ncross SuoNo.da.from Hime Shima. to No.ga.Shibltl1blooldng the entrance to theNa.val Port of Tokuye.mo..

(2) J.oondQY .}reql(0.) Main .shipping Inne, t.hrllugh Suo Nl'ldo.. Thesecondo.ry oreo. specified was bounded by :

33/58N - l31/06E33/53N 13l/01E

33/S4N 131/14E33/46N - 131/10$

33/47N - 131/54E33/4lN 131/53E

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2 . S TR ..; .T EG Y.e ND LQ ,N O F Q PE Rp .T IO N :~. Strategic Importange of Tnrgets:

(1) Shimonoseki is the most important shipping oenterin the Japanese Empire. Sinoe persistent subaard ne attaok hall p ra.o-tioully elimin ted shipping through Bungo Suido and Kii Suido (south-ern entranoes to the Inland Sea) a.nd t he oonstriotion of the Japaneseec o ncmy to the Inner Zone hilS s ubstantially reduced the mnritime im-portance of Nagoya and Yokohanu.\,thCilmajority of all shipping en routeto the Japanese homeland passes though Shimonoseki Straits. It isestimated 'that 500 ship passages per month occur through this stro.-tegio water-way, tot~lling some 2,000,000 tons of shipping. Theblocka.ding of this area by mine attack can be expected ei thar to iso-late water-borne shipments from the main terminal ports in the westernportion of the Empire. 9r to forca a diversion of shipping south ofKyushu or north of Honshu. thereby adding hundreds of miles to normalShipping routes and exposing vessels to attack by our submarines.(2) The industrial centers and cities in the area pro-posed for blockade in this operation include Yawata, Kokura, MOji,Shimonoseki, Tobata. Wakamatsu, Chofu Onoda, Ube. Kanda, nakatsu,Bofu and Tokuyama, The first 6 named form one of the major industrialcen.ters in Japan proper. This center includesl the largest plantsprodUCing pig iron, ingot, and rolled steel in the Japanese Empire;important plants producing alumina. heavy industrial chemicals, andsemi-finished iron and steel products; and a large part of the Shi-koku coal fields. the most important in Japan. The area has someplants manufacturing machine tools, machinery parts, and finishedequipment of various kinds. but its primary importance lies in thefact that it furnishes a major part of the coal, iron, steel. semi-finished iron and steel, and other basic materials for further pro-ceSSing in the manufacturing districts in central Honshu. Shimono-saki is also a major transportation center. being the terminus of the2 costal rail line connecting with central Honshu and the terminusof the important rallraod tunnel under the Strait of Moji. A recentconcentration of war industry is reported at Knnada, and reportedimprovement to the harbor at Chofu may indicate war industries there.Tokuyamn is an important naval fueling port; portions of the Japanesefleet "''ereobserved there after the Carrier Task Force attacks on the

Inland Sea on 22-25 March 1945,(3) Partial blOCkade of the Horoshima and Kobe-Osakaarea will as Le be eff'ected by blockading Shimonoseki, insofar as ,allshipping to these areas from the Outer Zone will be required to passthrough waters now under interdiction by our submarines,

b, Tactical Situstion:(1) The mining of Shtmonoseki Strait waS planned as ~support operation fOT the invasion of Okinawa Gunto in the RyUkus.The immediate tactioal objectives of the mining operation were toprevent supplies and reinfor.cements being sent from the embarkationposts of Mutsure and Hiroshima in the area under attack: and to restrictthe movement of the Japanese Fleet in opposing the invasion.

c. Details of Planningl(1) Operational Planning:

(a) As indicated a general directive to preparefor mini:l-laying operations was given to the 313th Bombardment Wing


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by the XXI Bomber Command on 23 January 1945. At this time 2 (e.ndlater 8. third) naval officers were assigned to the Wing for mine-warfare liaison, In the period intervening between this date andtbe first minelaying operation, an extensive experimental programwas carried out to determine mine-laying tactics suitable for B-29alrernft. making maximum use of the radar _quipment consistent withthe previ.ous training of the orew radar operators. These tac'ticswere then taught to all crews of the Wing by radar-navigator specia.lists, and additional instruction in mine warfare was undertaken.All ordnnnce and armament personnel in the Wing were also giventraining in mine handling and loading prior to the first mining effort.

(b) The directive for Mining Mission No, I, issued11 March 1945 from the XXI Bomber Command, specified the time andarea of attack, the approximate number of sorties and density of theminefield, the preparation of the mines, and general limitations on thealtitudes of att~ck,

(c) The tact ical planoi ng for thi s operation '~C.sCarried out by the 313th Bombbardment Wing, In this planning. nneffort was made to make maximum use of experience ~ained in theCommund' s l ow .. ev el i nCe nd io .r y a tt Et Ok s o l' l.' th e~ajor -l"c .po.n ese;!U es,and at the same time employ the most suitb.bla mine.lo.ying to-ctics forthe B-29,(d) Selection of approaches and mine-laying runswaS largely influenced by enemy antiaircraft defenses, heights ofmountains surrounding the area under attack, position of a good initialpoint, and suitability of: radar aiming points for indl vidutl.laircraft.(e) All mine-laying runs were planned and briefedas radar runs, Beco.use of the advantageous position of the moon, 0.11crews were 0.1110 briefed on the possibilities of visual runs on theirtargets should they be v i s ibl e.(f) The large number of aircraft that would be overthe target area necessitated a scheduling system simila.r to that em-ployed in ,Jrevious low-level inC6ndio.ry attacks. Airoraft of ForceAble und Charlie were to take-off at one-minute intervals, while thoseof force Baker were to take off at 30-second interva.ls, All Ilircraftwere to proceed independently to the target. An appropriate time in-terval separated the major forces to reduce to a m in im um t he p os si bi li -ty of aircraft on different axes of attack over the target area. Atthe same tillie,it was planned to saturate enemy de!'euses insofar aspossible.

follows: (g) The Tact1 c ml PIQP fpr this PoerBtlon was as1. Force Able, consiting of 24 aircraft of the505th Group, was to mine the western entrance to Shimonosekl Straitsat an nIt! t ude of 5000 feet and axis of attack of 300 degrees true.from the i ni ti al p oi nt ,, Immediately following this attack, Foroe

Baker, oonsisting of 20 airero.ft of the 504th Group and 30 !I..ircraftof the 6th Oroqp. was to mine the western approach to ShimonoseklStra! ts at an a Iti tude of 5000 feet an.d a xi s of attack of 240 degree!!true from the initial point,

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Forces Ableand Buker: BaBe1st Check Point2nd Check: Point3rd Check PointIndividual I.P,

'Unlanlwo Jimo.Ooordina.teSada. Mieo.ki

and/or R.A.P. for

l5/04N 14S/38B24/S0N - l41/15E32/30N - 132/3.QE33/20N - 132/01EsoJlh sart..ie

~. The third force, Force Charlie, oon-sisting of 31 airoraft of the 9th Group. was to mine Suo Nado.. 25at un altitude of 5000 feet, nnd 6 at an altitude of 8000 feet, allat different axes of attack from the same initial point, immediatelyfollowing the attacks of Force Baker,

(2) Details of AttaCk Planl

(11) All deta.1ls of the attack plo.p. are given in313th Bombardment Wing Field Order No. 16 with amendments thereto.(3 )petGTmiMtion of Mirp~l

(a.) Complete co.lculations were mOodeby the WingFlight Engineer to deterlIline the maximummine load possible on thismission. As a result of these Computations, it was decided to loada.ircraft with 12.000 pounds of mines and no bomb bay tanks; in theCase of some aircruft, it WIlSdecided to permit the Group FlightEngineer to specify a minimum load of 10,000 pounds for individualairoraft not oapable of c~rrying the full load,

(b) Mine Locdfng for eech o.ircruft was specifiedin an annex to Field Order 16. For purposes of' security and euseof handling. all mines were identified by a code designation whiohis given o.s Po.rt II. Seotion C, of Annex A, b f this report.

(c) Details of handlin~ and loading of mines ina.i rornft VI.ere specif led in par agr-aph 4 (:3) thru 4 (9) of Field Order16 and in Taotical SOP 15-8 (Part It (E) of Annex A).

(4) Mining Insruotionsj(n) All mines were to be laid:~ 1 of 2 methods

outlined in 313th Bombardment Wing Tactical SOPNo. 100.2 (Part II(d) of Annex A). The specifi cut Lon of the method to be used in eachtun was given in an annex to Field Order 16.

(b) Jettisoning Ilreas were deSignated immediat~lyoff the runway east of Tinian and en route to the Japanese homeland.Instructions for jettisoning mines were furnished in paragraph4 (2) b thru 4 (2) d of Field Order 16.

(0) Instruotions were given to 0.11 crew navigatorsto accurately plot the positions of all m.ines rOleased, includingthose jettisonsd o.nd those relso.sed in Case of emergency. Detailsof radar scope photography to identify the position of mine releasewere gi vqn in pEll'agraph 4, (11) of FieId Order 16.

(S) Nayigationw, P~!lnning:(a) Details 9f Route:

1. Routes PIAnA0p ~ Out:

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Foreo Able I Manauver after attackl stro,ight oheo,d until clenr ofanti.airero,ft a.t Yawo.to.. then left to 32/36N - 131/45E.climbing to Ia minimum o.lti.tude of 8000 .feet c.rosBingKyushu.

ForC'e Baker; Maneuver nf'te.r ntto.ek I after cl eo.I'ing to right of anti..0.1reI' at are0. 0.tYawnta. alert tuxn to 32/36N - 131/ 45E,climbing to minimum altitude of 8000 feet crossing Kyu-shu.

Force Chn.r11e: Maneuvel' aten 0.ttaek : e11mb B tr.ai ght ahead for 1minute after mine release, then turn right continu-ing to cl fmb to minimum nIt iude of 8000 feet cross ...:!lng Shikoku. Adjust turn Ili'ter mine release to o,voiddefenses at Tokuyamo..

Force Charlie: Snse1,st Check Point2nd. Check PointI.P.Individual B.A.P.

Tinio.nlwo Jimo.Coordino.teSada Misakifor each so.rtie.

(b ) RoutegP hpned - Return I

1st Check PointLeaving LandBase

CoordinateNeo.r NobeokaTinlan

1st Oheek PointLeo.ving LandBase

CoordinnteNear Nobeoko.Tlnlan

Leo.vingBase

Notsu So.k:aTininn

15/04N - 145/38E24/50N - 141/15E32/30N - 132/30E33/aON .. 132/01E

33/37N .. 130/34E32/36N .. 131/45E15/04N .. 145/3BE

3S/37N - 130/34E32/35N .. 131/4SElS/04N .. 145/38E

33/09N .. 133/13E15/04N - 145/38E

(5) R@dar Pl O D n 1 n e : : A l1 .mins-1o.ying run.s were pLaanedand. bri.efed Q. S ra.dar runs.

(7) .Ro.d[\r Gounter Mtp.sures: Routine sear ch w~p1o.nnedfor enemy I'lldll.l;' signo.ls on frequencies be~en 38 mco..nd 3000 me by4; obse r-ve r.s ,

(8) Air-Sen. Rescue Plqnn tog I(a)~: The No.vywns furnished with details of

th1.s mise1on. and requested to furni!>havo.l1able fnci11ties for o.ir-sell rescue purposes. The following we.re lml..dao:vo.ilab1e:

~. One submo.ri.ne WaS stationed at 30/00N ..1SS/00E for the e.ntire miss'ion.

ll. One destroye.r was 5tationed Il..t 28/0vN ..137/00E from 262.200Z to 27.2200Z.

A. One plon.e tender wa.s s.tatlonad at 18/00N-144/30E from 262QOOZuntil the end o.fthemis.sion .!. On~ Dumbo o.ircro.ft WillI stnti.oned o.t 20/00N_142/00.E from 271900 to 272100Z.

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(b) XXI Bomber Command assigned 2 Super Dumboaircraft to orbit the submarine position at 30/00N - l35/00E from27l500Z to 271800Z.3. EXECUTION OF MISSION:

a. Take-orf I Aircraft of Force Able were SCheduled totake off at 270600Z. Force Baker at 270630Z. and Force Charlie at270700Z. Actual take-ofr was acoomplished as follows:~ A IR CR AF T A IE BO RN E F IR ST T AK E::9 FF LAST TAKE-OFFAble 22 27055BZ 270622ZBaker 49 270627Z 270657ZCharlie ...,ll_ 27Q5BZ 2 1 Q : Z 3 Q ZTotal 102 270558Z 270730Z

b. Route Outl The course flown was generally as briefed.W o substantial deviation was made en route to various initial points.Deviations in mining runs may be seen on charts of mining runs.(Annex A. Part II)o. Over Target:

(1) Primary Areas:(a) o r the 102 aircraft airborne, 92 mined primaryareas. A total of 549 Mark 26-1 or 36-1 and 276 Mark 25 mines wasdropped in primary minefield~. A detailed breakdown of the types ofmines and their locations is given in Annex A, Part II.(b) Times of release of mines by Force Ablevaried from 27l337Z to 271435Z. by Force Baker from 271408Z to2 71 50 6Z . a nd by Force Charlie from 27l410Z to 27l542Z. Altitudesover-all ranged from 4900 feet to 8000 feet. Headings varied inaccordance with mining instructions, Length of mine runs variedfrom 1 to 16 minutes. Indicated Air Speeds ranged from 185 to 230miles per hour,

(2) Secondary Areasl(a.) Two aircraft of Force Baker placed 12 Mark25 mines in the alternate area, minefield Love.

(3~ J et ti sp ne d:(a) The following mines were dropped in the jet-tisoning areas spe cUied in theFte ld Ord!'!rl

Mark 25AbleBakerCharlie

o6o

371121 3 . , Ro ut e B ac k I Briefed route was followed substantiallyby al1 aircraft, although a someWhat wider turn than antiCipatedwas necessary to avpid a.ntiaircraft and searchlightll in the Yawata.

are a,


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e, Lqndinr: Airoraft of the main force lQnded at baseunder good weather conditions as follow!1~ F ir st L g.n di nr Lg.st Lg.ndin,l\.ble 272033Z 260055ZBilker 272034.Z 260235ZCharl1e 272024.Z 2723Q6ZTotal 272024.Z 272306Zt,~I Three B ..29' s were lost, presumably to anti-aircro.ft over the target area.g. Operations SummGry!

(1) Nqvigntion: (See Annex At Part I for details).Routes, initinl paints. o.nd radar aiming points were verysatisfaotory. Of 50 runs plotted by analysis of radar scope photo-g i- ap ll B, 52 p or , oe nt we r e ", ith in o ne .. a.lf mi ie o f' b rief ed lo eat ion .

(2) ~I (See Annex A, Part II for details).Mining results are oonsidered exoellent. In Field Mike minefield,d ens i t y i n t ho mo ..insh ipp 1ng Ch ann el woo s a ppr oxi ma .te ly all p1a&ned,and the anohorage north of Waknmatsu was effeotively blooked. InField Love, a high attrition of shipping is to be expected if thee ne ll lYa tt em pt s t o u se e st a.bl is he d c ha nn el s,

(3) Flight Endneeringl (See Annex A, Part III fordetails). This miuion waS the longest flown to dllte by the 3l3thBombardment Wing. D1stanoe WQS 26'78 nautical miles. Cru.lse outwus made at 5000 teet o.nd oruise back WetS between 10,000 and 20,000feet.(4 ) ~I (See Annex A, Part IV for detailS).Radar equipment operated well on this mission, with 95 per oent ofaircraft over the target having operative AN/APQ-l3, A total of86 mines releases was made by r ad a. r o ff se t m et ho d.(5) Gunnery; (Se~ .Annex A. Pa.rt V for details),EqUipment operated very flatisfo.otorily with only 3 ma.lfunctiono forthe entire Wing.( 6 ) A i .r ..Ss ll ..Re s t) u QR e po r t WQS reoeived that a. B . ..gcrew was bailing out at 31/S5N - 133/15E. Tw o B-29's were imm-ediately dispatohed to searoh the areo.. The submarine abo madea search. Results were negutive.

h. W e A.thelI (See Annex a for detailB). Weather did notint'erfere with the exeoution of the mission.i . C om mu ni ca t:l on s:

( 1) Rg .dg ,ra oun ter Me as ure I (See Annex C. Pllrt Ifor details). A routine search wus oonduoted and 2'7 differents ig na ls V le re i nt er ce pt ed .

(2 ) ~I (See Annex C, Pllrt II for detll.llo).A totlll of 13 HF/DF bearings was requested and obtained. Netdis oi pli ne w ao gOOd.

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j. I nt el li, eD oB S um ma ry I(1) Enemy Air Opposition: (See Annex D, Part I fotdetail B ). ~emy Il.itoppo s iti o n was 11ght, only 13 a t to .o ks be i n gexperienced. It Willi ina.ccurate o.nd uno.ggressive exoept in onecase o f Cl tt o.o kby rooket-firing fighter which pressed to 200 yards,

In o.ddition, o.pproximo.tely 60 aircraft were reported sighted butn ot a tt o.c ki ng .

details).(2) Enemy Antinircrottl (Sse Annex D, Po.rt II for

(a.) O ve r m in ef iel d M ike , e ne my n nt lo .i ro ra .i' tfi rewas rated as heavy and medium, intense o.nd m ore accurate tha.n onprevious n.ight missions. Fire wall ooordinated with effeotivesearohlights . V essels in the Wakamo.tsu areo. contributed to th eintensity Qf the barrage.(b) Over minefield Love on east side of thestro.its. opposition wo.s meager to moderate and inaccurate. Theo.ircraft closest to the Straits rated the intensity 0.8 modero.te.

(3) Mining Results: Detailed analyses o~ theresults o r the mission are shown in Annex A, Po..rtII. Sectiol1llAand B.

ikLr.t/nv~CURTIS E. LeMAy7Major Generill. US ACommanding.


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\

A N N E XA

QPFlBb,1 'IONS

Bxhibltt Track ChartPart I - NavigationPart IIMining

Soction A - M l n i . n g R os i l l tsSection B Charts S h o w 1 n g Mi n a L oo a t i onSection 0 Code Designo.tion. of lIines and

Mine Operation.S!,!ction D- Yinelo.ying ProcedureSectio.n E Mine Ho.ndling and Loading

Pa.rt III Flight EngineeringPart IV - RadarPart V - GunneryPart VI - Air-Sen Rescue Ohn.rt

Misdon No , 4127 March 1945


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APRIL 1945 "TRACK CHART"

o

SECRE

OKINaWA

15

a

IIJ-...--r-IJII

TRACK CHART XXI SOMBER COMMAND130 135.

MISSION NO ~7DATE 27 Morch 45XXI BOMCOM.313th. WIn

KEYForce- - . " A "----- "S '

iiLii"".;"i! iiiir " C . ",;;;. ,,'_ "0 1IJII

, 'CHICfJl JIt.1A

_--+---25"JIMA I

IIII

-_. --_

140'

1 < >.d'f;UAM

v IIJ145SECRET RE:PROOllGED 35t~ PT U


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P A R T I - N A V I g A T I O N1. Routes seleoted were very satisfactory.2. A shortage of large Loran map!! CD-used some d.if fic ul ty bu t t hesituntion is being remedied.3. ~:

0.. ~ti9ns Over Tpn:et I Visibility over the target WD.Sgood. Moonlight melds the I.P. and la.nd check points visible. A l Awas meager to heavy so that evasive IJ.ctionw a s neoessary.b. I P Qu d A, P,: The I.P. and A. p. were well selectedand could be picked up easily in the radar soope. They could beseen visually as wall.c. Use of Rn.Q!U' and Efficiency: Tw o m et ho ds l ft Ir eu se d. inlaying the mines. Ons method was a time run out from a Ro.dfU' .AimingPoint and the other used !lforward slant r~e to Radar Aiming Point.In general, the radar equipment was reported to function prop0rly.d. Jimin, Point pnd Desoription: Each aircraft was ass1gned~ indiVidual aiming point us described in the field order.e. Mal1functions:

(1) 6th B om b Gr ou p:(a ) Ale 836: R ac k m o. lf un ct io n C au se d 0. 4 seconddelay in the rele(lse of the lust 6 mines in the bomb bay.(b) A le 881: One mine dropped ut the correot timebut when the others did not relea~e. 5 we re sa lvo ed 45 s eco nd s l at er .(0) A l e 889: Sulvo ot the last 2 m in es o cc ur re d

30 minutes after trai.n:rem out. One parachute to.i.1ureW!l.S noted.(d) Ale 901: Jettisoned all 5 mines i n j et ti so n-ing area just o1'ter take-off dUG to engine fai lure.(e) A l e 889: Six mines had to be so.lvoed npproxwimately 15 0 ,seeonds o1't(3r n or ma l r el eo .s 9 of other 6. Broken wire in.aft bomb bay is believed to have caused hanging o f bombs.(f) A l e 783: One mine had,paraohute failure.

(2) 9th Bomb Group I(n) A l e 791: Sixth mine had paraohate failure.(b ) A l e 57*: Sev$nth mine had p~rQchute failure.(C) A I r ; 8 35: Fi fth - n ll ne h ad pa .r aoh ut e f ail ur e.

(3 ) 505th B o m p Group:(n) A l a 813: One mine wns jettisoned out of targetarea on the way back to base due to ro.ck ma.lfunction.(b ) A l e 334: This A le returned to base with 1 mine.Station tripped but the shaCkle would not release the mine.

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15/89

(4) 504th Bomb Group I(a) A l e 349: The eleventh mine wa.s released 30 seC-onds late and the twelfth mine was salvoed beoause of ,tation malfunc-tion.(b ) A l e 853 a Eleven mines in rea.r bomb bay were re-lea.sed a minute late due to malfunction of bomb bay door.(c) A l e 8521 Rack malfunotion ca.used eleven mine, tobe ,alvoed 15 seconds after first mine was released.(d) A l e 834: Three mines in forward bomb bay weresalvoed due to ma.lfunotion.

4. Radar Soope Photo Resultsl0.. Force Abl e (24.A/C,) - Plotting do-to.were not avo.llable tor4 ~irornft. either beca.use there were no soope photos or because thephotos obta.ined were not plottable. Five aircrnft dropped o .S briefed(within 1 0 mile), fl.nd6 within t mile. Of the remainder, one droppedwithin 2 miles. one within 3, a.nd Il. t hir d w ith in 10 miles of the brief-ed position. The rema.inIng a.ircra.ft returned eur1y or did not get offth e g ro und .b. Force Baker (50 A /e) - P lo tti ng do .to .we re n ot o .v o.l lo .bl afo r 19 o .i rc ro .f t. N in e o .i ro ro .f t dr op pe d as briefed or within t milesand 2 within 3 miles of briefed position. Three aircraft were miss-ing, a.nd the remainder returned early or did not tQke off.c. Force Oharlie (31 A/C) - P lo tt ing d a.t a.w ere n ot av ail abl eon 19 aircraft, including aircraft not complotipg the mission. Six air-craft dropped as briefed or within 1mile, and the remainder droppedwith o . n error of 1 mile or leSB.d, The results of the I:Ina.lysisre shown on the cho.rts. (SaeSQotion Bf Part II. this AnnG%.) In general, errors were not ~stem-utic, but were of a compensating nature, thus produoing a good mine-

field pattern. For FJ . detailed a.nalysis of the minefj,elds. see An.nexD. Part III.e. A tabulation of the (lI,Ocura.ols o bt a' 1n ed i .6 as !'ollows I

a . I i 0 , 1 1 : g,!; i; !iumb!i!rf B ! ! . 1 l 1 i fer!i!!ilalii!Hr;eimile 25 52Imile 14 282 miles 6 123 miles :5 610 m1le8 ...l --L50 100%PART 11 - SWC'UON A - MINING RESULTS

1. The followiqg report is submitted 1n accordanoe with WarDepartment letter. AG 476.1 (20 Ootober 1943).


16/89

a. The charts following this section show the position of nIlmines planted in this operation. A legend on these charts indica.tes tbemethod of plotting so as to differentinte between positions establishedby rudor scope photographs, by the na.vigator, or by the assumption thatthe crew p1a.nted their mines as briefed for o.frora.f't hat did not returnto bllse. Pos! tions estnbl1shod by rador photography a.rebel1eved accur-ate to 1mile, and those by the navigo.tor between iand 1 m1ler there isno way of estimating the accuracy o r the other positions.b. The number of B-29 aircro.ft schedulsd for this operationwus 105. Of these, 3 failed to tQke off; 5 did not plnnt their mines inprimo.ry or secondary areasj and 3 fo.iled to return to base.c, The marks and modifica.tions of all mines planted in thisoperation are listed in Table I (for code. Bee Section B) and are plot-ted on the oharts following this seotion. A total of 837 mines of alltypes was planted in fields MIKE and LOVE, of which ~ were Mnrk 25~d 549 were Mark 26-1 or 36-1. Because of the number of differentmechanism preparations. and the fact that these were distributed between26-1 and 36-1 cases, no attempt was made to specify type case in the1000 Ib size. o r the Mark 25 mines, approximately 80% were equippedwith acoustic meChanisms A-3 Mod 1 MMl without ship counts or dela.yedarming. and 20% were equipped with magnetiC mechanisms M-ll with de-layed ~rming evenly distributed between 1 and 30 da.ys and ship count,evenly distributed between 1 and 9. Of the Mark 26-1 or 36-1 mines.approximately 80% were equipped with aooustic meChanisms A-3 Mod 1 00without ship oounts or delayed arming. and 20% were equipped with mag-netio mechanisms M9 Mod 1. half with 8-second dead period and half withlO.S-seoond dead period. About 63% of the M9 Mod 1 mechanism with 10.5-seoond interlook dend period were fitted with 20 ohm shunts across thesensttrol operating coil to coarsen the sensitivity, and had no delayedarming but had ship counts in the ratio of 67% on 1 and 33% on 2. Theremaining M9 Mod 1 mechanisms had 68% set on I-ship counts and 32,( on2-ship oounts (l-a hip count is the eq ui valent of no PDM' s ). With tbea pp ro va l o f Co mm o.n de r- in -Ch ie f f U. S. Fleet, no sterili zers were used onany of the minss. The locations of all jettisoned mines are given inTable II, Section A.d. All mines used in this operation ware obtained from MineA ss em bl y D ep ot N o . F ou r. T in io .n .e. All mines dropped in this operation were fitted with 6 ftparachutes. Six parachutes were observed by crew members to fail, o.nd5 short static cords were returned. This is ~ negl1gible peroentageof the total mins6 dropped. Parachute installation Was ~s speOifiedin To.eticll.l OP 15...;8See Seotion E). A.n undetermined number of jet-tisoned mines ware observed to explode on impact with the water whensto.tio lines were out or paraohutes failed. One aircraft jettisoningmines frem 7000 feet with severed static lines reported toot 7 of 12mines Mark 26.1 or 35-1 exploded on water impo.ct.t. The basio taotios used in this opera.tiol'lare given in 'ro.o-tical SOP 100-2 (Section C) and in paragraph 2 (c) of basio report. In

general, an effort wClsmade to hnvo as lIlanya.1rornft Il.S poss1ble dropon forward slant range from n radar aiming point. In some Oases, however.it was necessary to drop on timed run or baOkward slant range from aradar aiming point. All IF's and radar o..imingpoints are speoified in.i.nnex3 of Field Order 16. Th.e g eneral method of planning and briefingwo.s lU I follows I


17/89

(1) Upon receipt of the mining directive f~om the BomberCommand, n planning meeting was held by the Wing Pl~nn1ng Seotion. A tthis meeting. no IP nnd lUis of attack suitable for laying each DI.ine-f iald were deCided upon. mo.king the best compromise between o.voido.noeof flak arens and high mountainous terrain. seleotion of good radara.1ming points, and se lection of most favorable nogle between the axesof the lines of mines nod the normnl shipping routes,

(2) After deoiding the foregoing, tbe minefields were de~signed by the Mining Section. taking into account depths of water, shipping routes, and grid densities specified by the Bomber Command, Mixedplane loadIngs for each a.ircraft were then specified by the Minto Section in order to aSsure proper distribution of mine types through thofields, (Only 1 size mine was used in any I airoraft to simplify load-ing.) These mineficlds were laid out on standard target oharts printedby the Bomber Comllltlnd.

(3) Overlays were than plotted on standa.rd target chart 1 for ea.ch string of mines, for use by the navigator of eaoh alrornft.

(4) The V/ing Radar Nc.viga.tor then solect.ed radar a.imingpoints for each run. Sio.nt ranges, distance of run, laying track, a n ddropping interval were speoified on no.vig-,torl s and bombardier's fl1mBiesnnd on ea.ch chart. The charts were then distributed to the individualnavigators through the Group Operations Offioers,

(5) ~neral and Specio.l briefings were heid in eae h of theGroups. At the special briefing for the navigators. radar no.vigo.torewere o,va.ila.ble to ass ist in explaining the individual charts and to mo.lcechunges as necessary.

(6) Upon complet10n of the mission, naVigators turned Intheir individuo.l charts. on which were plotted the positions in whioh themines ha.d been dropped. VIing radar personnel then plotted the run de-termined from rado.r scope pictu.res. A comPosite overlay of these chart.Vlo.S used to determine the positions of all mine:; 0.8 plotted on the np-pon.dad Chart.

g .. Co.sunltio6 sustained in this o_pera.tion inolude 3 nircraftlost, :3 o.ircroft with ma.jor flak dCllnage.5 aircraft with minor flakdo.m.a.ge,2 men wounded o.n4 32 missing. All cQlualti"l5 were sustained inth G Y J. :If t, rA T J.er e a,

h. Critique of Minefie1ds;(1) ~lald MIKE(western approaoh to Shimonoseki); The

appended ohart of the minefield shows the final lOCations of all minesplanted. 1 .. sma.ll percenta.ge of the mines fell on la.nd or shallow water;their lOCations nre such, however, tna it must be assumed that 0.11 themine types used 1n this operation were oompromised to the enemy, Theminai'ield dell.B1y in the main ohannel is a.pproximately o.s planned, butls centered slightly south of the main shipping lane. T h e Q.hcborngenorth of WakOJna.tsuis effectively bLecked , oonsidering the large shQalaxeas loco.te d the rEI The weakest portion of the e.pproach ill througbM'izu6hima.Sufdo, whl.ch is not known to be used as a. shipping 1MB,

(2) Field LOVE (Suo Nada.)I Final post tions of 0.11 minesplanted are shown in the nppended ohart. A heavy oonoentra.tion of mineswOoSe.1d in the main shipping lane north of Rime Shima, bLLt the fields

r--.r-~-----------'----~~~~~~ED-----r------------------~---7f56a>,_n_ ~! !l ! '2Zr / '. #


18/89

are aUght!y wenkto either side of the main channel, particulllZ'ly inthe dl)8perportion. of .HimeShimo.Suido. because ot o.ireratt returnlnsearly or c.irorot that did not get off the ground. The string at mineaspec1tied in Amen.dment 5 to Field Order 16 wa . s lo.id well consideringtM short time available for briefingl 0: rack fo.ilure. in. 1 o.ircro.ft.howe'ver, Caused 11 3..mile gate to be left in the field. Mine strings65 and 70 are minea that were plo..nted in the s13oondo.ry area by Fo.reellJ..KER. Stl" ing No 70 is partiGular:ly well situated. It should besta.ted that Field LOVEa.s lo.l.d in this operation 'lfnS not iaten.dod foroomplete blooko.de. but that high o.ttrltion to Shipping should resultif the enemy attempts to ueeestablisbed Channels.

Tp.ble I to Seet~op ASW! lma, ry o r Mines Planted

(SHlMONOSEKIo nd SUO N ADA. areas)Pie14 MIKE; Forc&!BiB (SHIM9NOSEKI)Mine Mo.rl-;36~1or Mo.rk 26 ..1(1000# she)

Q21-B'* CU ..1l9 C12",,89. Dll ..B9 -D12-89 D21..89 D22..B9M,O 13 9 0 0 15 9

TOTAL STotal Mines Foroe ABLE ~FisH. Mlkej FgreEi M K E R (Sm;MONOSEKI)Min.G Mo..rk 36-1 Q21-B!1 Cll ..B9 C12-B9 D11-B9D12-59 D21..119 D22 ..B9or Nark 26~1 182 14 9 9 5 6 2(1000# slz:e)Mine Mnrk2S(2000#sl;!;6 )

221

TOTAL 156.TatOolMlnes Force BAKER oW

Fie ld LOVE I Force CHARLIE (suo : NAD,A )Mine Mo.rk 36 ..1 Q.21..B9 On ...B9 a l.2..B9 nll ..B9 D12..!9 021-89 D22-B9or Mark . a s . . 1 77 8 is 4 . 1 0 0(looqi! /lite) TOTAL 96Mine Mork 25(2000 '# she)

TOTALTotal. MIn.osPO.I'OIl! OHARLIE 132228-Tota.! Minas Plo.nte.d.c o For oode deaignc.tion see Section C o r tbis Annex.

FlED7fS6C15


19/89

Tilble IIo Seg~iop AS l ! ! !! ! ! !2 . t J l : 2 ! : M~D2a~2~~i!2P2~

ll2. kk ~ Lgtitude Longitude5 25 Q21-B9* 15/03 N 145/53 E1 25 Mll-P9 15/03 N 145/53 E6 26 or 36 Q21-B9 15/05 N 145/55 E2 M or 36 011-B9 15/05 N l405/55 E1 26 or 36 D12.B9 15/05 N 145/55 E1 26 or 36 Q21-B9 15/05 N 146/00 E1 26 or 3e q21-B9 31/59 N 132/42 E1 26 or 36 Q21-B9 29/50 N 135/29 E10 26 or 36 Q,21-B9 24/51 N 138/38 E1 26 or 36 012-89 24/51 N 138/38 E1 26 or 36 D22-B9 24/51 N 138/38 E10 26 or 36 Q21-89 27/35 N 136/16 E1 26 or 36 011-B9 27/35 N 136/16 E1 26 or 36 D22-B9 27/35 N 136/16 E6 26 or 36 Q21_B9 14/56/30 N 146/10/1.5 E:3 26 or 36 Q21-B9 15/01/15 N HIS/seilS E1 26 or 36 012-B9 15/01/15 N 146/32/15- E1 26 or 36 D21-B9 15/01/15 N 146/32/15 E1 26 or 36 OU-B9 15/01/15 N 146/3~15 E For code' des igno.tlon. se e Secti on C of thi s Annex

Table III to Section ASUbl!D! l . rv of Mines Planted .i.nPrimID Arens

Supplement to Table II In knne; L of Starvation ITotal mines sOheduled 960Mines in A la fuiling to tnke off . . . . . . 36M in es j et ti so ne d (See Tv.ble II to Section A) 56Mines planted in Field L (Runs 65 & 70) 18Mines planted outside Field M (Run 28)Mines r etu rn ed ( Fi el d. hiI: Run 9)

12 -..1 .,123

T o t a l mines p lo . n t B d i n p r1 m o. r .Ytarget 8:57

-16-


20/89

TARGE. A-OUTER

SE Ji lE.''$.O.! ..E II 5 7,5 8 ~

t I ~AUtU; ;l ld !J M1L i: 10'MIl.ES eNI '~~~~:~L.~~~~~or

MINES PLANTED BY FORCE A8LEMl'NEF1ELD MIKE

(5!l.IMONOSE'KI STRA IT S AR.EA)"LEGEND

o-----e n. A 1000 I . e . . MrtE$. . . . . ._ A PPROX . POSITION VeRIFleo BY SCOPE PHOTCl3. .. .. .. .. .. .. , .. 0 S CO P E P H O TO S . . I'I AV lC ;A T O Ii S' I! ST IM P IT ED F p os nl aNNUMERAI . S IM liltA TE QRO E It 01'" M I"'IN"'lI:llr'1' A N O "It!!Ttl! !. K II! .Y TQ SCOP! ! 'P~OTO.$ 11"1 MI'I~"'II'I.s.


21/89

SECRET I

SC::A'L.E I,!7.i5Q6! ! i, l! iO T 1C ,o ,L ,1 M I L. .E 1 00 M I L. E: S O ~

I '500,0'0 0 ~ CAL-E OFW E 'E ,M 5- PL OT TE ,A : l

TARGE, A- OUTER

" '~s

M INES PLANTED 8'( FORCE S A K E RMJNEFIEL.D MII


22/89

SI~CRET

. ...~

..I:I~.

TA,RGET A- OUTERSC4I..,E I !7.~b~

I I NAI JTLIJ Ad M!L. .E re MII.. ,EB ON~,~O'O~Oi!,)O SCAk. OF'WIE:E :;~S P ,-OTT! " l

I- I

A LL M IN E S PlANTED BV FO RC ES A f)LE ' A ND 8A f(E RMINeFIELD MIKE (SHIMONOSEKI STRIiJTS AREAl

.LEGEND


23/89

TARGE A-OUTERSOAL .E I I!.".!!IIIII~

I. Nl\tJTI(;ALI ~ "E. 1 0 Iot IL .i iS ONr '!:~~:~,~~~~,~:,O~

DESIO" OF" MN~FIe:L.O MI


24/89

MIN!!. PL.AMTEO BV FORCE ~LIEMINEFISLD L.OVE (SHIMONOSEKI STIIAms AREAl

LEGEnDla. 1000L.e. MNI!S,. ..aOOOL.B. M'N~$APPROX. pO.ITIOn V.RIFIEO ..,.KQPa ~o .NO acOPI!PHO'TO$. n"'IGiA'T-OIlS ".'TIMofiio'T1! 01= POSl'TfON

NUMERAL-to IMDICA"TE OQOI!Q OF R.un AND AlaEIC~"( 'TO SC9~_ PHOTO'S. 1M MAI=2GU", So

o Qoo oo TARGET L - TseAL E I I,U!t7a

(I "A~nc:.t ,l .. MIL. !: i ao MJLEs ON1.11000 ;000 SC;;ALE II Q'F

WEEMS, j II t. .QTTE'~1~,


25/89

----~~


26/89

DE;SIQN OF MINEFIELD LOVE( ~I-I'M or",0 &EK.I 51'I


27/89


28/89

SEGRETo I

;y- -'T4flI~~i,.:U'AII,~..... ; , .... II' I


29/89

...~/./ ,-/


30/89


31/89

. l . Q . B . ! I c. TH IRD snmOL - NUM BER - SlITP COUNT SETTING (NOT PIlI SETTING )

R O D E NO123456789a

ACTUATIONS TO FIRE , N Q W ! E li ON TB)1234.5576910

d. D ASH B ETWEEN TH IRD SY M BO L A ND FO URTH SnmO La. FOURTH SYM BOL - LETTER - D ELA tED ARM ING SETTING

~ Q J 2 E ! & I l ' ER A B l 4 1 H Q '2t~I~ QQ~ L l l I I I I l E . A R Y I l i w mil':A 45 min N 20 claysB 3 hra 0 25 dQoYIC 12 bra P 30 daysD Ie bra Q 35 dllYIE 1 dllY R 4.0 daysF 2 days S 50 daysG 3 days T 60 dllYaH 6 days U 70 daysI 1ays V 80 daYI!IJ l c b days W 90 daysK 13 d!IYs X 100 duyllL 15 days Y 110 daysIi 18 days Z 120 days

1'. F I F T H SY M BO L - m . l M E IER .. S 'l 'E R I L I Z J . .T I O N T rnE A F T1!:R .A RM I N GG O D S N U M B E R1

?3456789

:IERIL IZA TION TIM E A fTER @ M IN G0-15 days15-30 do.ys

30-50 days50..:s0days60.110 days11O-~40 da.ys140-170 dc.ys170-200 dc.ysnone

EXMlplos,CI.. ~-26, Mod 1 Mine.

) .1-9 14echnnism3 SBC dead poriqd2 r ever se lOo;lksNormal Sensitivity

Codal Boy A 1 3 , . B6

3 hour clock delayNq delayed arming\33 d(l.y staril1zutionSet to fire en Srd ship

b. Mlc-25 mineM-ll MeChanhmNorma.l Opera.tionNormal Sensitivity

. .( lOdE) I

10 days delayed arming86 day sterll1zl.tionSe t tq fire on tenth ship

; .An, :;10. :r5


32/89

Mk-36 Mod1mineA.3, Mod1, !tIM1Medium(2) senaitivity

Oodel Sgn

3 Hour delayed Il.rmi~Noateril1r.a.tIonNo ship-count921 - 89

SECTION DI:JinelPJd,ng Procedure

1, It is direoted tha.t the mineloying procodure olltl1ned below beplaced into effect immediately.2. Mlnela.ying by a.ircraft of the 313th Wingwill genero.lly becc.rl'1ed out in wec.ther unsui tc.ble to.r hit;h-Ievel precision bombil\li.Depending on the particular tactical sitllation, altitudes of o.tta.okmay~ary from severnl hundred feet to 50,000 feet. Each run will be ma.deby ro.da.r, and genElrnlly by single-plane flights, If viatbil1 ty and themethod used are such that the bombo.rdler ce.n got v1auo.l check points, hewill take over the mining run in the samemaMer 0.8 n bombing pun, but 1nmost Cnsas ro.dnr techniques will be I.laedthroughout.3. Minelaying from aircraft presents the fundamental problem o tplacing the mine at a designated position in tha wo.tcr, using ro.do.ro.im-

ing pOints or visua.l check points on adjc.cent const lines (ma1nlaad orislo.nds) to loco.te that position. This requ.ires thAt 0. reference pointmethod be used. sinca the aim1ng point will not coineide with the target("hioh is the deSignated position 1n the wnter). The one outstandingdifference between minel~ying c.ndreference point bombing is thnt t h emines ~sed ure equipped with small parachutes which retard their speedof 1'0.11o.ndalso ccuse them to drift downwindafter role~Be from the~ircruft. At high winds o.ndnIti tudes of 25,000 to 30,000 feet, Q. minem o y drift downwinduS much !l.S 5 to 6 m.iles before hitting the wo.terIato.ltitudes of 5000 feet and normal windll, the d.rift will be about imile.Therefore, in nrrlving at the dropping position it is necessary to cor-reot for the wind drift of the mine as well ns the oourse nnd rate ottb9 a.ircraft, In other respects, minelo.ying is similar to reference.point radar bombing.

4. Regardless of the method.used to arrive o.t the dropping posi.tion whenplnnting mines, it is necesso.ry to first compute this posi-tion from the target lOCation a.ndwind data. over the target. Strictlyspeo.king, it is not possible to do this until o.fter an o.couro.tewindrun hns been made in the vicinity of the target, In pruct1oe. however,it will be a. sto.nding prooedu.re to compute the dropping position from thepredicted wind given o.t the last weather brief1ng prior to tnke-off.This caloulation will be revised, if necossnry, after o.naCoura.te windrtlu has been made during the apprOach to the tlll'get.5. The method to be used by the no.v1go.torin oomputing thG drop...ping pos! tion of the first mine from Elp,chniroraft is as follows:

a. Fromthe predicted (or measured) wind at nltltude, computethe bnll1atio wind that will be l10ting on the mine during its time offall. This is done by ascerta1ning the approximate bal11st10 fo.otorin Table I and multiplying the wind at 0.1i tude by tht s faotor; assumedirection of bullistlc w1ndto be the same 11 8 thnt of wind o.taltitude,

313th BombardmentWingTo.ctlcalS. O. p. Number100-2.


33/89

'D . In the Fie14 Order for la.ylng the mines, the tarljot (orlntend6d position of tho .flrst mine) will be specified in relo.tion to0. ro.dcr CLimi~point (RAP), to!;ether with 1 of the 2 methods of lnyl!l1outlined in po.ro.grCLphs a.nd8, On 0. cha.rt of suitable sco.le, plot theta.rgot loco.tion o.ndthe no..wind course of the CLil"cra..ft. The lo.tter w111be determined frolll tho mothod apecif'iGd q.s follows I IfMethod.w isgiven, the direction of the no-wind oourse will bG fram to.rget looo.tionto ra.dur aiming point. while ifMethodm i8 given, the direction w111be from ro.dnr Ilimill!;point to ta.rget. Theft o.scortain the wind drift ottho mine tor tho bo.llistio wind determil'l.Odin s\ib-pc.ro.e;ra.ph11, flbovo.In tho Oo.SOof the lOOO-lb mine (Unrk 26 o.nd36 80ries), this will befound i:.nTo.ble IV, while in the cnse ot tho 2000-1b mine (Uo.rk 25 80rlos)th1. will be found in To.ble V. If 0. mixo_d~oa.dof mines is being droppedon. tho same run. use tho wiJl.d~t'li't tound in Ta.ble IV. Plot the wine!drift vector by laying off the diato.nee thus determined baok into th~diroction~rom whioh tho wind is blOWing. On the vector di~rama shownb~low, nt this point vectors RT o .nd Tl'1 helvebeen drawn.

o . Newdetermine the no-wind ra.~o of tho first mine to bodropped frolll the true o.ir spoli'dnnd tho 0.1ti tu.de. Thia"rill be toundin Ta.blo IIfor lOCO-lb minos nnd in To.ba III tor 2000.1b mines. llea.s-1.11'0 off this disU1.ncowi th 0. pl1lr of oempo.ases. n.nd dro.yt0. oircle on thevector di~ram with '1 " 0.5 oenter a.n~ro.dius equid to the no"'lrind rangeof the mine.

d. Computethe hoo.dlng of the d~oro.ft duri~ the lI11n1ngrunby I l l 1 - o.pproximo.tlonmethod as follows. Drawveotor aT'. whioh elpproxi-mntes the oourse of the airoraft during the mining run. Set th~s courseon a.nE6Bcomputer. and determine the drUt angle of the aircraft torthe wind at 0.1t1ude. Md 0r Bubtro.ct thi a nng1e f.rom.the cou.rse (d.-pending on whether the drift is left or right respeotively) in order todetermine the hending during the mining run.a. Determine the droppinj!; poBitioll or rolense point 0 . 1 ' the

first mono (p) by drawing a Une from '1 " to the circumfarenoe of thoro.nge cirole Illong a bearing 1800 from the heading of the aircra.ft ~deterJnined in sub-parngr!lPh d. The Gffecti ve tro.jectory of the mine 1.nowgiven by the dll1ita.ncePT, with PT' being the component due to thoset i'o",o.rli of the mine. and TIT the component due. to wind drift duringthe a.ctuo.l time of fall.

t. The OO\1rsato be ma.degood in the minitl! run wU1 be givenby the d1l'eetion of the vector RP, while the offset distance (or hori-zontal range trom ra.dar aiming point to release pos1tion tor the firstllIina) will b~ the length of vector RP.g. In the cas" of 10Viwinds that will be encountered at lowo.lti tudes (be19w5000 t't). the dire9tion of i U ' will lle app.l'Oximlltelythe

sruno as RTt and the hoe.clingmay be assumed to be that of RT'. thu. e11m-inll.ting the naoes.slty for atep (d) a.blllve. In the (1).80 of very high 0:-055wi.nds at h1gh altitudeB. ho'Weve.r,it may be neoessary to make a n. additionaloa.lcult>.ti9n. This wHI oonsist ot detebnining the rert.ed heading n.08a-sary to make good the Oourso RP; if this hoad1ng is ~roeiably d1rforo~from TIP, ro-plot tho poUtion pi on the 'ballia of th9 .nowh.oatUngandthon detormine the reViI!Ied.cour.o. R , P ' , to be usod in laying.

he Thh method of computing tho dropping poe1tion is nlu.trll~04 ;in tho Vootor Diagrams and SamploCalcI11o.tion.'

.IlilJl


34/89

O a Twobasic methods will be used for m1nolaylng, the oholoe be1DCdependont upon the particular taetioal oltuation involved. UothodJlDiwill be spocified when It is oonvaniGnt to fly towa.rds the radar alzn1ngpoint (RAP ) but not OVGr it, and wil l be particularly suitod to low al-titude ~ttack. while Method T W O will b o specifiod whon it is convonientto fly over e. rlldar aiming point, IUld w111 bs partioularly suited to ac-ourate minela.ylng close to shore. The two mothods are explained in do-tail below.

7. Method O N E (Target a e t w o e n :FlaM and M Pha. From the predicted wind data. the navigator will plot a

vector diagre.m a e shown Cn Page 35. following the mothod in paragrapb5 . H e will soale off the horizontal rango R P . in nautioal miles. Hewill then convort this horizontal range to slant rango for t h o altitudoto be flown, and give this slant range to th0 radar operator. Th e laterwill set up a bomb rolease Circle for this s l a n t range on the P P I soopowhGn on tht;) mining run,

b, Maleoan accurate wind run when approaching the target aroe,.If the measured wind is significantly different from the pr~dlctod Wind.tho na.vlg~tor will ro-plot the veotor diagram on the b~sls of the nowwind data, and will furnish the new slant range to the rad~r operator.

c. The IP will be ta.ken about 30 mileS" from the r.adar ~1m1ngpOint. along course R P a .s f'ina..lly det0rm.ined on the basis of' the wine!data. being used,

d. Tho turn will be made on oourse a .t the IP in the same man -nor 0.8 in n b9mb1ng run. The first mine will be released by the banbnrdier on 0. Mark' from tho radar operator when the bomb roleaso circleintersects the rnd!:lr cdming point. Tr'l0 nir speed nnd cou.rse mu..lltbemo.intnined throughout the mining run.

e. The bombardier will preset tho anglo betwoen th e vortioo.l~nd tho radar aiming point at tho roleCl8~ position on his bombsight. a n ddrop visually if' he eun SOO thG radnralming point. This will roquirothat tho bombardier compute this anglo from the altitude Bnd horizontalrange oaloulated by the naviglltor.

r Sue:ceed~ng mines will usuo.lly be droppGd on the SlllJII)cour-se o.t pre-determined time 1.nterva.ls, whiCh will be mea.ured on astop-wo.tch by the bombardier.

g. The naVigator ....,ill taks a plotl1re of the radar soope at tbEldropping posltio~, while the r01e~se cirole ia still on t b G BOOP$. andwill note the run~ and time at wh19h the photo WaS taken.

h, One of the gunners (de6igno.ted by pilot) will observe themines dropped to ascertain if the mine po.rnohutes open properly.

a. If the a1ti tude of attack is grea tar than. 5000feet, theprocedure ol1tlined thrOl.'.gh pa1"agraphs 8, b to iwill be followed. FoJ"al t itudes of 5000 reet 0 r 1esa I al tar thi s method e. s gl ven in paragraph8, j.


35/89

b. From the predicted wind data. the n~vigator will plot thevector di~gr~s 1:1.3hownon Page 35, following the method in paragraph5. Hewill sonLe off the horizontal range. lIP, in nautioal miles. H itwill then determine the ground speed that t.he o.iroraft will be making inthe predicted wind from an E6Bcomputer, and calculate the time of run ondeo.dreckoning to COVGrdistance lIP. This oalcu1ation will be checked bythe bombardier.c. Makean accurate wind run when approaohing the target areasas in paragraph 7, b . If a re-plot is necessary, the n~v1g~tor will re-ca.1cula.te the horizontal range and ground speed for the newwind data,!ll'l.dm time of run to cover RP. This co.lculation will again be checked

by tho bombardier.d. If the a.ltitude of a.ttack is above 5000 ft, the ra.dar oper-o.tor will be supplied before the f light with slant ranges for synchron-1zing with the bombarder on the RAP, a .s in a. bombingrun. Thepurposeof synchronizing isto supply the bombardier with a precision poin'\: tramwhich to start a ti~ed run on dead reckoning. If the altitude Qt attackis 5000 rt or below, the radar operator w111be givon 1 slant runge tosot up a bombrelease circle for starting tho timed run, and no aynchron-

lzatlon will be used.e. The IP wlli be taken as in paragraph 7, c and the turn w111bemadoon eourso as in a bombing run. From this point on, the mining runwill be made in the samemanner as a bombingrun with navigator and pilot

kUling d .r itt. and ro.do.roperator and bombardar killing course. '!'heonly difference will be tM bombardierIs procedure, a .s des!lribed in par-a.graph 8, e below.f. The bombardier will "et a disc speed into the bombsight forthe SOO-lbbombfor the altitude flo~. )(hen the navigator gives him theground ~peod. ho will ascertain the tangent of the dropping angle forthat ground speed and n1titudo:l in bombing tables for the SOO-lbbomb.Hewill pre-set his rate index on the tangent ve.lue th~s determined. Withthe rate' motor off he will then engage the telescope clutch, witb thetelescope index oppos1te the first synohronidng anglO, At the commalld'Mark- from the radar operat.or, the bombardier will turn on tho rate motor.

A .t tho' nOJl:,! 'ohsoli:'angls tho radar operator w1l1 again ~ll' out tho nEiwm.ngloo.nd 'Mark' when in thnt position. The bombardier will re-ut thetelescope index to agree with the Sighting angle and will make an adjust-ment with ths rate knobI tu.rning 1t in the seme dlrE!otion EUI the dh-placement knob is turned. This adjustment will be repeated as Bachangle, and the rate will thus be killed on the IU.P the same as in bc:mbing"The bombnrd1erwill not have the mine release when his indioes meet. how-ever, but w111watCh the telesoope index until it is oppos1te 0 , andwill sta.r~ his stop watch 0:" this time. At this point. the nircro.ftshould be directly over tha R J . . P . At the end of' 1\1s timed run. he willtoggLeoff' the rirst mine. 1l.ddiiol'1nl mines will be Q.ropped011 course at apre-determined time interval between mines.g. Visual ~yncbronlu:t1on or Qourse determinnt~on will be usedwhenever visibility permits.h. The navigo.tor will to..ka III picture of the ra.dar scope at thedropping position of the firllt mine. The radar ope1"ator will lea.ve thelast range oircle used tor synchronhatiol'l on the scope until after thispicture ill tnken: the naviga.tor will note this slant rangs and.the range

and time at which the picture was takGn.


36/89

i. 1 1 . gunner will observe pnraohuta funotioning as in paragraph

j. If the altitude of atta.ck is 5000 feet or leas, the methodoutlined in b nnd 0 above should be modified to allow for the fnct tho.tthe timed run will begin before (rather than over) the RAP, as stnted inparagraph a , d. In such cases, the length of run on dead reckoning willbe the distance RP added to the horizontal range for the slo.nt rangemnrkerset in by the radar operator.

9, The above procedure utilizes the sa.medivision of responBibil1tyamongthe crew as the bom.bingprocedure.

SECTIONEM in$? Handling! am Lop.d.1ng*

1. In order tc ho.vemines opera.te properly, it 18 ab801utely nec-essary that the procedure outlined below and on the check.otf lists befollowed ip handling, preparing, and installing mines in aircraft.2. The Mine Londing Plans (Page40-4l)' will be prepared by the Wing

Ordnan.oeOfficer a.ndwill o.ccompllnythe Fi sId Order + '0 Group Operations.There will be 0. separate liIine Loading Pla.n for ench Airpla.ne Commc.nder.a. Group Operations Willi

(1) Place th e number of the airplnne that the AirplnnaCOllllIlnn.derill be assign.Eldon both sheets of' the Mine Loading Plan.( .2) Distribute Sheet I of the LolldinlJjPlnn to the Group

Ordnanoe Officer and Sheet .2 to the Group ArmrunentOfficer ll11111Gdlntalyafter the plane aSSignment is made.b. The Group Ordnance Offioer will distribute Sheet 1 of thoMine Load.1ngPlan to the Ordnance OffiCers who are to load the partIc-ular aircraft concerned.c. The Ordntl.nceOfficer (and His Sectign) Willi

(1) Dra.wall the mines speoi!i.ed on the Uine Loading Plnnsin hi S pOllSass ion and th,e necessa.ry pD.l'B.chut~s,relsasil mechanisms, andsoluble washers IUlddeliver them to the daslgnnted aircraft.(2) Give Sheet 1 of the Uine Loading Plan to the ChiefArmorer for completion..(3) Plo.ce the mlnes on bombcrad~es and inliltall t h o ! ) PD.J'-achutss a.nd soluble washers on the mincs.(4) Attach the statIc cord.s to the pInna after the minaGare loaded.(5) Complete 1;haordp,a:ncecheck-ofr list and return to theWing Ordnance Ofrloer.

d. The Group ArmamentOffioer will distribute Sheet 2 of theMine Londing Plan to the Ohlef Armorers assigned to the aircraft OOJ loo"cerned ....313th Bombo.rdmentWing Tnotlcd S.C.p. No 15008 .

-34-


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'~Q.R!IVETOR DIAGRAM; F eR MINELAYIID COMPUTATIONS

ME I'H O D O N E M E T H O D '! W O /../AIE OFMIAIES

Pr " -" ~- _ ,1/l5r, \ - - - _ _ NIAIE1II ---vr------ ------...:\ I T\ /" ' ' ' '-

/ _sr \I' /-If'/IIL IIi, -,I ~------------I " ' , / _ _ - - - - ,\ I"~ _--" _, -.._, .... p

\\,

S J.M P LE C OM P UT AT IO N STarget (T): 5 n.m, bearing 180 from RTemperature: -40C.c.! .A.S.: 179 mph (155 kts)M illi:: Mark 26-1 (1000 lb size)

,,I,

\,

Altitude:25,OOO feetTrue Air Speed': 265mph (230kts)wind: 15 0 kts fran 270OT.Ballistic \lind: 0 .54 x 15 0 or81 ktsN041ind Range of Mine: 0.62 n.m.Iind Drift of Mine (TT'): 2.60 n.m.

M El'RO D O NEApproximate Laying Course (BT'):Drift Angle:Aircraft Heading: 'Horizontal Range (RP); ,Laying Course CPR) or CRP):Layine: Heading:Droppine: Slant Range: ,Tangent of Fr,,-s~rt Angle:Bombardier Is PI'e-set Ana1e:Ground Speed:Run-out Tims:

1680 T.400 Left2080 T.5.35 n an,1720 T.2120 T.6.75 n.m.1.30552.50

- 35 -

METHOD TiIO34 80 T.40 Right3080 T..4.40 n.m,3520 T.3120 T.

156 kts.102 see ,


38/89


39/89

8~apS wipe the rela~se off the mine. In order for the release to .tar" on tM mine during descent and to Oollieoff on wo.ter impact, it is ab.o-lutely necossary that the bands be tightened to the correot tension, Ther el ea se m eO ho .n 1s m cnn be oriente.d in ~ oonvenient pod tion on the casoas long as the paddles are placed directly over the lugs W01ded on thomine Case.7. The par~chute is oentered on the mine case by means of 0. small

pin on the oontor of the tnil plate and held on to the release by meansof severnl shackles. On some mines a smnll well is located in the centerof the taU plo;te. On these minos 0. oircular plate which fits into thisWOIl must be screwed into the paraohute before installation. Tho para-ohute is opened on dropping by a statio line ~tto.ched to a rigid memberof tho plnno. It Is necessary t~t the paraohute be oriented on thomine as shown on sketoh 1, so that this statio oord will come out o t t~top of tho pooket of the parachute. For correct opero.tion th. parachutemust b. ~bsolutely dry.

B. After the mines nre installed in the plnne by the armament craws,it i.s n.eoossary for the ordnance crews to ntto.ch the pn.rnchute sto.tiocords to the plilne. It is neoessary to follow the method shown in sketch2 in attaChing static lines to prevent premature opening or failures o tthe pnrnchutes. Most of the parachute stat1c cords hnVG 0. small clasp ontho end. These onn be f~stened to nny oorreotly located member. On pnr-o . C l l l u ~ stat tc oords without olasps. it is neoessary to tie the end otthe cord to 0. member o .t leo-st i inch in diameter or to n clasp of anotherstntic 11ne. The length of the 11110 should nevor be shortened nnd thoend must be nttaohed to 0. smooth surface free of sharp edges. Minesshould never be londed if the soluble washers or po.ro.ohutes are dttmp.


40/89

>,ATIC IAfE ~'-~- . .~"'ATIC.llVE NI/SrJ./i,Jl viii PARACHtiTePaCKer (V17i'lINTHIS ANGLE.

j7A,ACHLI;:e; ,Md$r #,orIS: //./ svL.Li?(? IF7h'ES-iE ricCo.-!p_


41/89

PARAC',t/tlTE- ;

1 -- - O

. 71IA7"t~ASE OF"ONS M/NE W/.t.NOT OP"e-N aT#;r.?,PARACHUTeS" .

Au S"LAC,tC /NST,4T/? tiNETAKEA./ (It? So7lAr '/'I,veWIJ./.. /VarPOt/I.. ONor,l-/~R ././,vE!J"oe eNPi-A A/I!: _

5"ket"C!k ZCCRRECTPCSITIDNING OF STATIC LINFS

- 39 -


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M IN E L O A D I N g P L A NSHEET 1

J . . IR P W , N E C O M M A N D m R , _DATE O F M ISSION i..- _~A .N E 00 . _

GRO~ _SQUllmO,.~ __RequiredDroppingSgquence Mlc-Mine COd ! Lotter

D l> .TE LD ADED ~ _TIM E LOADED , _

Bomb Statiop ( ro r B om ba rd ie r)Sequenc, Dropped12

56769

101112

Cheoked o . f t e r mines w e r e l oa . d e dBy . - = = = ~ ~ = = ~ - - - -CH IEF A RM O RER

M n r k 2 5 M i n e a p o O # size, Marks 2 6 and 3 5 Mines 1 0 0 0 # s 1 & eROUTING II . O r c u p O p e r G o t ! . n s ro r P l a n e N U l l l bel.

2. G r o u p Ortl,no.DceOfficer for distribution to Ordnanco Offioerooncerned.3 . Ordna~ce Orficor for d r a w i n g r e q u i r e d m i n e s from m i n e randydump.,-Chief Armorer for reoording bomb s t a t i o n s .

S. Plane Bombo.rdier for record.ing sequenoe dropped.6. Interrogo.tor for Int'orm.o.tlon and forwClrdlng to Wlng Ordnan.oeO f f i o e r .


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S H E E r 2J . I R P L ; . : N E C O M M A N D E R : . . . . . . . _PL .i.NE NO ., _G R 0 1 I P _

DATE O F M ISSIO N ~ _OATE LO l!.D ED _

S Q U . h D R O N , _ TIM E LOA J)ED '-- _RequiredDroppingSeQugncg Coae Lettgr BombStatign12

45678910.1112

C F g E F . i J j. M C ! R . ! jJ ft . S 9 R E Q K L I S T I I n 1 t \ 9 . 1 a1. BombStations ass1gI;i.ed ~nd recorded.2, Bomb sto.tiona prepQ,red for lO!ldlng duignated minos.3, ,Proper bomb stD.tion, -and side o!'ple.ne plo.eec1. onsll,ch

min!> with Ohttlk.4. Mine,; lotl,ded.,5. Paraohutes are ary.6. St(lot1c cords are connected to rigid members of the plane,

o.b9~ and aft of thepe.raohute, oo.po.ble. of supporting'250. 1l:!5.7. Mines o.re loaded in proper ato.tions,.8. Sheet (1) given to plo.ne bombardier.

9. Afte.r plane returns. tag sto;ll1c l~nes with p,lane numberand d().tl,>!l.ndreturn toVHng Ordnance o.fficer.(lIfnrk a s Mina2000# size, Mark. 26 & 36 Mines 1000# IIba)ROUT ING I1, Group Opero.t1ons fo.r plan.e numbsr.2. Group Armtlmant OCfloer for distribution to chief D.rmorer concerned:.3. Chi.ef Armorsr for oompletion nnd forwarding to Vi1.ngOrdnance Officer


44/89

(Fill o~t this part of list after mines a~e loaded in plane)Static cords are connected to rigid members of the plane,above and aft of the par uchu'te, cnpnb Le of supporting 250pounds.P nr o.c hu te s o .r e c or re ot ly o ri en te d.Tie cords in pcckets of parachute are into.ct.All slaok is remo~ed from statio lines o.nd taped withSootch or friction tape.Static lines are free of tie straps.Sto.1:1011nes are olear of eac h other so thnt relGo.se ofone mine will not open oth~'r parachutes.Return wooden washers and LUCl te covers to ,i'ingOrd.no.noeOfficer.

O R P N 4 N C E C H E C K - P F F LIST FOR M I NE L O A D I NGA ir pl an e Co mm nn de .r D e .FInne Ne. _Gro~. _Squadro .. _

(Fl11 out this part of 11st when mine is onoradle and before paro.chute ls instnlled)Dry soluble wo.shers (2) installed in enoh mine.Securing nuts tl(;ht over each wnsher.L uci te c ov ers (2) removed from each mine.Parachute r&lease mechnnism oriented oorrectly on mine cnseso that inertia release is free of lugs on mine case.Orientation lug placed on pase with cott~r key if one isnot welded to Case.Lead. end of inerth. relense on forward end of releaSemecho.nism.Shear wire instnlled through wnsher nnd relenae pin andends bent o.t right o.ngles.Relense mechanism conforms to curvnture of mine Case. (Nolnrge nir gaps between mine Co.se and raleo.se mechanism.)R el ea se m ec ha ni sm hnS proper tension. (Inertia weightshould just slide with force nnd should feel sloppy whenmoved from side to side.)Lock nut tight.

5.

8.

11 .12.

(Fill out this purt of list after pa.rachuteis ~nstal1ed and before loading mine)Ce nte rin g p lat e p Lnc ed on para.chute if necessary.Parachute correctly oriented on mine onse for londing onproper side of pI nne ,Purnchube shroud liM s ha .o kl e p in s t ig ht ,Small wire fed through eyes of p~ruohute shroud lines hac kl e p in s.Soluble washers and parnchute a.re dry.

L oa de .d u nd er s up er vi si on of --:"~-~---T( Cre w Chi or)

C he c ke d by __ - - -- ~ ~- - -- - -~ ~ -- ~ -- - -( O rd n o. nc o O f fi c er )RE'l'URN TH IS CHEDK .OFF L IST T Q WIN G O RD NA NCE OFFICER.


45/89

P.hBT III - FL IGH I' !!JN GIN EEB1N I{

I, This mission Vfll.S flown by ind1vld)lal aircraft. The mu:imwnround-trip ground distance on this mission wo.a 2B76 nnutiCo.l miles. longertho.n o.nymission previously flown by thh Wing. The oruise out "o.s at5000 foet. The mining a.ltitude WtU! 5000 i'(;Iet; the return was acoomplish-ed at different altitudes between 10,000 and 20,000 feet. This missionW0.8 similar to other 10w-0.1i tude Missions previously flown.

2. The oruise to the target at 5000 feet wus a.ccomp1ished at np-proximately 198 mphCASby most aircraft. The aircraft were in autorich during the climb o.ndwere able to mainto.~n auto lean power set-tings during the entire cruise before going on the mining run.3. The mine-run a.ltitude.was the same D. S tho cruising altitude,consequently there was no olimb nseessary,4. Powers used on the mine-run proved interesting. The mu:1mamCASfor the mine-run was Bet at 230 mph to be under by 10 miles the re-oommend0dmaximummining speed of 340 mph. The 9th BombardmentGroup

set maximumauto lean power at 5000 feet (2150 RPMand 33') and gOil 215mph 018 on the run. Other Groups set approximately 2300 rpm nnd 39'during the lII.inerun period of about 10 to 18 minutes and calibratedclose to 230 mph. The extra power wns mostly as 0. precaution in OaS8nn engine should be lost. .

5, After completing the mining run, the aircraft olimbed to al-titude to return. Power was held on and the high speed of the l!ombingrun mild\,)it possible to c11mbrapidly. Ths return Viasaecomplished ataltitudes between 10,000 nnd 20,000 feet; the aircraft returning at 0.1titudes hbovo 15.000 feet generally made the most eoonomical return andreturned sooner,6, Summllry:: Groups

0.. Flight DQ.tg. 6th !WL .Q!:th 505th.t'l.ver::l.geombLoad 12,100 12,000 12,130 12,840Average Fuel to Target 3,413 3,220 3,452 3.390l.vernge Fuel U.s.edTotal 5,872 5,561 5,810 5.745,;"verage Fuel Remo.ining 908 1.129 975 956MinimumFuel Remaining 659 656 634 438Average Gross Weight 133,177 133.35,7 133,357 131,915,Initial)Average Total Time 14:29 14:33 15:01 14:59

~I These figures do not inClude aircraft bnding at 1woJimo..b. The use of briefed metro winds on return from mission isof extreme importnnce l briefing of crews on metro winds immedia.telybefore the miSsion ha.s helped grea.tly.c. Cruise control wns satisfo..ctory on th:j. B mission.

j.!l.Q lLi 1


46/89

PART III - FLIGFn' ENGWiEBINQ

1. This mission wns flown by individ~al aircraft. The maximumround-trip ground dist~nce on this mission was 2676 nautical miles. longorthnn nny mission previously flown by this Wing, The oruise out was at5000 foet. The mining altitude was &000 feet; the return was aocomplish-ed at different altitudes between 10,000 and 20,000 foet. This missionwns similar to other low-altitude missions previously flown.

2. The cruise to the target at 5000 feet was acoomplished at ap-proxima.tely 196 mph C.hS by most o.irornft. The o.irCraft were in autorich during the climb and were able to maintain auto lean power set-tings during the entire cruise before going on the mining run.3. The mine-run altitude.was tba SBme as tho cruising altitude.consequently there was no olimb necessary.4. Powers used on the mine-run proved interesting. T h e mnxlmumGAS for the mlne-~n was sot at 230 mph to be under by 10 miles t h e re-oommendad maximum mining speed of 240 mph. The 9th Bombardment Groupset m~imum auto lean power at 5000 feet (2150 RPM rund 33) and got 215mph 01.5 on tho run. Other Groups set apprOXimately 2300 rpm nnd 39

during the mine-run period of about 10 to 16 mi.nutes and oalibratedolose to 230 mph. The extra power wos mostly as 0. precaution in cnsann engine should be lost.5. Aftur completing the mining run, the o.ircraft Climbed to 0.1.titudeto return, Power was held on and the high speed of the 1I0mbingrun made it possible to climb rapidly. The return was accomplished ataltitudes between 10,000 nnd 20.000 feet; the aircraft returning at 6.1-titudGS b.bovo 15,000 feet gene~o.lly made the most Goonomioa1 return andr et ur ne d s oo ne r.6. Swnmo.rv: GroupsIl,. Fli!l;ht Qg,tg. m ~ ..Q!th .Q:th

;.vero.geBomb Load 1lhlOO 12,000 12,130 12,840J..verageFuel to Target 3,413 3,220 3,452 3,390Avernge Fuel Used Total 5,872 5,561 5,810 5,745";'vero.gauel Remaining 906 1.129 975 966Mi nimu m Fuel R.emaining 659 656 634 438J..vGrag~Gross Weight 133,177 1 33, 357 1 35. 357 131,915(Initinl).hvernge Total Time 14:29 14:33 15:01 14:59N:OTEI T he se f ig u.r es do n ot i no lu de airoraft landing !. 'I t11 '0Ji ma .

b, The use of briefed metro winds on return from mission isof extreme 1mportnn06j briefing of orews on metro winds immediatelybefore the mission has helped greo.tly.0. Cruise o0ntrol was satisfactory on this missioll.


47/89

P A R T I V - M D b R1. o r 102 ~irornft on taka-off. 101 or 99% h~d oper~tlve AN/APQ-13.After 5 early returns. of 97 over target. 92, or 9 6 % . h ~d o pe ra tI veAN/APQ-13. o r a ir or af t I nn di ng , 90( h ad o pe ra tiv e A N/AP Q- 13.2. ~ total of 146 radar wind runs ~d 1216 radar fixes Were taken;

landfall 'WtLS at 0. .0 nverage range of 42 n t lu t ic a l m i le s.3. Loran fixes numbering 1056 were taken at average maximum rangeof ~pproxim~tley 1200 nautical miles,4, Eighty-one mIne releases were by radar-offset method.5. Slf u n otionsl

a. AN/AP9.-13 I(1) 2: Crystal current fluctuating.(2) 3: Selsyns out of phase.(3) 11 Drop in crystal current when switching from 50 to20 mil e range.(4) 31 Range limited to about 30 miles.(s) 1: Bomb release 11ne w e a k .(6) 1: Set out on return. possible because of' bad air-c ro .f t e le ct r i on l s ys te m.(7) ~: Inverter went out over the tnrgot. used Loro.n in-verter on wny baok.(8) 1: No crystal current.(9 ) 1: J itt er y t ra ce .(10) 1: Sebyn frozen.(11) 1: Seotor senn out.(12) I: S11glrt VOltage f I uc t u a t i On,

b. ANLJi!:N-41(l) E ll Inverter d1fficulties.(2) I: Station #3 not properly onlibro.ted,(3) 1: 6SV'7 tube burned out. no replncements.


48/89


49/89

. a . li rU .J .1

PART Y !!UJm

1. Gwman "aro o.hrted o.ppronmntoly 1 hour b6tora la.n4t!111 IUI4won on t"' 019rt until '11'611out to aGelon tho return. Gunnar. wera b.-etl'ucted to notify the pilote of UIIU8u.o.l h!lppen1nga, Th1. w as Co.rr1edout, and it elided n grsnt denl in tho auooeuful Moompl1ahlllant ot them.1l18ion,

2, Of"tM o.'1rornft ovc'r onemyterritory, only < 5 mo.liunct'ioM oteq_uipm


50/89

APRIL 1945 PART

I----1--IIII

----+--IW~ JIMA I

IIII

IIII.---,--[ -_IIII

KEY.- SUBMARINE0-SURFACE VESSEL.. - NAVY DUMBOIl..- SUPER DUMBQ

I

' CHICHI JIMA

TRACK CHART XXI BOMBER COMMAND SECRET IiEPROOUCEO 35th.? T . U.


51/89

B

Part I ~ Weo.ther SummoryPort U Chart - Foreoa.st \'fenther vs Observed Weather

Part III - Prognostio Maphrt IV -Synoptic Map

Miss1 on No 4727 MArch1945


52/89

BASES:

ROUTE,

P A R T I - . W E A T H E R SUMl4ARX

PL A NN IN G F OR ECh ST~: 5/10 low oloud, b~se 1500 ft, tops 8000 ft, with 5/10mt d d 1e o loud, from 10 to 11,000 ft, both deere o.sing

temporarily from 1000K to 16001 to 4/10 a nd i nc re as in g~go.in. Showers light to modero.te in m or ni ng ; m od er nt eto heavy in afternoon.Saipan: Some 0.8 o.t Guam except showers less intense, bothperiods.

KObe &:Oso.ko.l Snme us o.t Tokyo except middle cloud inorease ocourlngne ar 1 00 0K.Sume as ~t Tokyo except middle clo~ incroase oecuringn e o.r 0 8 O O K .

O p e ro. ti e n al F o r ec a s t

Route To 20on: e / l 0 low oloud, baseOute 1500 ft. top 7000 ft; 7/10 middlecloud, base 13,000 ft, top 14,000 ftl8/10 high cloud at 30,000 ft; visibility12 mi dr op pin g to 1mi in BCll.tter13dainshowers.

To laoN: S/10 low cloud, basG 1200 ft, tops 6-8000 ft in we~front with shower activity; 3/10 middle cloud, bo . s e11,600 ft, tops 12,000 ft.

To 24oN: 6-7/10 low cloud, base 2000 ft, topa 6-7000 ft,To 27oN: 8/10 low cloud, base 1800 ft, tops 7000 ft with lightshowers. 4/10 middle cloud, base 1200 ft, tops l4,00ott.To 30 oN; 3/10 cumulus. base 2000 ft, tops 4000 ft.

TlIRGETS: Tokyo &1 : 4/10 low cloud, bus e 3000 rt, tops 4500; 7/10 middleNo.goyu cloud, buse 12,000 ft, to 14,000 rt nfter 1200K.

Bnse at 5/10 low cloud, base 1500 r t fT~e Off; tap 7000 ftl 5/10 middle cloud,bnse 1~.000 ft, top 13,006 ft; 5/10 bighc lo ud , ba se :, 30 ,0 00f t j va i bi) .ity 12 m!reduced to 1 mi in scattered showers.

290N to 25~: 6/10 low cloud, bnae 2000ft, top 6000 ft; 3/10 high cloud. nt30,000 ft, '&sON to 30oN; 6/10 low cloud. b~s~ 2000ft. top 6000 ft; 4/10 middle cloud, base2000 rt, top 6000 ft, 4/10 middle cloudat 17,000 ft.

W eo .t Mr E nc ou nt er edB/10 oumulus. buse 1500 rt, top700b ft; 8/10 a lt oc um ul us, ba se10.000 ft; 5/10 cirrus, base25,000 ft; visibility 15 mi low-ering to 2 m1 in soatteredshowers.To 20OW' 5/10 cumulus, base1500 ft. top 6000 ft; 4/10 alto-stratus, base 10,000 ft, top14,000 ft 1n l aye rs ; 5/1 0 ci rr us ,buse 25,000 ft; visibility 15 milowering to 2 mi in seo.ttere~m o d e ro. te s h o we r s.20~ to 300N I 4/10 oumu1ua be ..o~lng a/lO, bo.ses 2000 ft, top6000 ftl 5/10 alt o c ur n u lu s , b as I '10,000 f t , top 14,000 ft, inlayers; 9/10 cirrostratus, baSI25.000 ft; v1sib1l1 ty 15 milas,


53/89


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TRU


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C O M M U N I C A T I O N SPar'll I - Radar COUl'lter Measures

Part II - Radio

Mission No. 4 727 M9rch 1945

-53-


58/89

P A R T I - R A D A R c O U N I ' J i R M F A t R m1. Purpose I. ' To oont1nue e.general ealll'oh p r o e r a m ct .mou'criDgenemy ac : a : m u . n i o a t ioIlS !Uld :radar ,sisals.2. Method.: Outlined as follows I

B. 28-143 mell". ,$..9 0 Dl Ce , 74-320 mod . 1000~3QO G mo

lARA " 1 A N < o - 21 APR 0 0 42 A P R - 42 A P R . 5

e. 3APA-6were used in connection with the radar receivers.

1. Strike BeFort/! (Mine" Away): Were not (l::611ed.or onthis mis:sion. .2. Fox 'Tl'ansmissrions' Weather and time were transmitted.3. a:egueneies r 3411 - R-5 5.4; 731_ R-5 5-5 ;11l6. - B-5 S-5. 34lRl' - I2%' 7.31~ - 64:( 1116~ -..2 4 %4. Navigational Aida.: D/F contacts attempted 13. completed 13 .5. Net Discipline snd, Security.: :Radio d.iscip1ine was good.Violations of security; One aircraft broke rsd1.0 silence at ~812Zto inquire about esp,

80/1500/99/330ON..l3200E_H76/1500/99!3300N-13200E_H75/1500/99/3300N-13200E_H92/9 0 0 / 1 2 / 3 3 OON-1 3 2OOE-HlOO / lOOo I30/3400N-13130E":H14 o /750/6/333ON-131JOE_H150/40 o/6/3400N-13 13OE-H155/750 ! 1 2 / 3 4 0 0 N - 1 3 1 3 0 E _ HIbO/SOO!12/3400N-13130:&-:H147/750/6/ 3 4 0 0 N - 1 3 1 0 0 E _ H96f,150 0 /1 2/3 33 O N..1303 OE- -H77/25 0 0/ 8/ 33 3 ON - J. 30 3O E '''H7 9 / 7 50/6 2 /3 300 N - 1 3 1 3 0 E _ H1 5 2 / 1 2 0 0 / 3 1 3 2 3 0 N - 1 3 1 3 0 E ~ H

PART II - RAPIO

I) Enemy 'l'ransmis I!! ions = Normal.7. Distress Messages.: None.

155/5 10/. 5/3 11 ON - 134 00E -H150/1 OOO!18/3 12ON.13400E-H1 3 5 ! l 5 OO/12/313ON-1335 OE-H100/3 0 0 0 / 1 0 /3140N-13330E-H95/10 00/17/315ON-13330E-H8 O / 1 0 0 0 / 7 0 / 3 2 0 0 N - 1 3 3 2 0 E - H145/700/2o f3210N-13310E-H73/400 /40 /3230N-1325{)E-H143/8 oO /S /324ON-1323 O E . . H1 6 U 1 0 0 / ' l 0 / 3 3 0 0 N - 1 3 2 3 0 E - H89 /20 00/5 O /2 7 0 O N . . 3 8 4 0 E - . H8 0 / 3 0 0 / 5 6 1 3 03ON-1343 O . E - H95!5 09t-3S/5Q300.il 3430E:" ,H


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8. F,guipnent Malfunctions: ANT-13- 7 trailill8 wire antezmaBmo.li 'uno tio ne .ARN-7 -:3 eense antennas broken.- 1 needle hunting.RC-J4.8 - 1 inoperative half way haDe.- 1 weak.- 1tuBe out.- 2 out.9. T.inian Homer '!I'aB reportedR-5 $-5 enroute to and from tarpt.OOIete.tion WBII extremely sood tran lwo J'ilna Bouth but heaVily J I I I I I I I e dnorth of Iwo J'ima.


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.Put I - Enemy Air Opp od tionPart II - Ene.myAntia.1rorat

Whelon No."27 Maroh 19~


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1. TYpes of F/A attacking. location andaltltY4e:

PA RT. I ~ F N W Y A IR o PP OO IT IQ N

5 U/ITeJtget area2 U/I JuatbeyObd target2 T/E U/l :rU8t beyond target2 T/E U/l Target area1 S/E U/l Target area1 Toll3'" Target area

~laimed as destroyed.2 . Types of F /A sighted but not e.ttackipB:

8 U/I 'l'arget area33 S/E U/l Targst area1 4 TIE U/I Target area1 TIE U/I Target area(with s/L in nose)1rving Target area1 TIE U/l Target area1 TJ'lil 'OIl Tokunruni1 TIE transport 5 mi. N of Hi lDa n . m e .1 U/l 10 mi. S of. Kudamatsu_Naval Base

3. TyPe am accuracy of enemy fire and type projectile{!: A'Uackswere ina.ceurate am unagreasive except for 1 aJ.rcraft whieh was attackedby enemy aircraft firing roe keta !Tall 200 yards. Other aircraft attackiI8used machine gun fire with one possibly mOUnting 20.mmcannon.

5000'5500'5000'500'5000'5000'

5000'500at500'5000'5 0 0 0 '8 5 0 0 '9000'3.50018000'

4. Enemyaircraftmarki!1&!.= At least 18 of the observed enemyaircraft had their ruoning lights on. Fow were reported as having 1white light on the wing; 1 had an amber light on the right wing tip;1 had a red port li.ght and an amber starboard light; .and others werereported merely BS having 1 or more runniIltg or navigiltion lights. Onetw.in.~engine U/l had a strong s/r, mounted. i. n ncse ,

5. Enemy Tactics, OneB..29 observea.. (by means of the ra.dar ee.ope)5 F/A following him. One. identified as Tony. finally attacked fran6 o'clock level l1ithbreaial;l1ay at 7 o'oloc,k in diving left turn. ThisAle fired only 1 ~. accurate as to alti't\ude but to the left of theB-29.Tracer.s were used , There Were reports of coard-ination bet'lteensearchlights end enemyaircraft over Yswat,a. B-2I)s wsreilluminateclby S/L. whiCh \'Iers then turned Off to allQW fightar.s to attack. One otour Ala was attacked by an U/l wb.ichdisch.argecl 2 rockets fran 200yards at2 o'clock high. There was no de.ro.age. o .r the 13 attacks, . 5were level B.nd 8 l1ere from above. No one clock position liaS favored.

7. Om-tfll-ctea and firet!~erV:l!. enemY aixcra:f'$ : Tactics con-sist(ld. of returning fire SSMon as E/A oJ:)en.ed:fire. MHd evasiveaction ;;rae also used.. s . . Results 9 hits on EtAI OneToW rm.8 observed to burst .intoflames aoo plunge st.raisht dOl1n"fl"ardnto .g-round. uhere it continuedto burn.

9. Qlaiibs by A l e and gun pOSition, 'I'ail gunner. 1 Tony destroyed.

( , Enemy t C l L " D l B tions: None uere obsGlI'ved


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PART II - E N E M Y ANl ' IA lRCRAl l '1. The weather over the target' was good. visibility 10-1.5milesand overhead a bright, full moon. The first Group mined the watersimmediately 'west' of the mouth of the Straits on a heading ~ apprCllti-mately 3000 crossing through the bay and turning lett around Ashiyaon the OngaRiver. The second and third Groups turned over the South-

ern Honshu island northeast of tm target and ran into the ShiJaon08ekiEay on a heading of 2400 crossing over and around western parts ofthe city of Ya'l"iateand turning left on departure. The tourth Groupmined the Inland Sea remote fran Sh:l:monosekiStraits breaking awayto rigbt{south)on leaving the mining area.2. The first Group into the target met m e a s e r and inaccurate A /Vtire from HimeJ : Lma . Then. both A/Wand heavy ueapons flak wa. repor-ted (meager to moderate and inaccurate) fran a point 5miles west atBotu. No searohlights were reported. Heavy flak was reported as bobsmeager and accurate at Ogori aId as meager and ilIacourate-. D o t , . . . . . .Searchlights, A I t a.ndheavy wea,POll8ere enoountered trQll both aurta.evessels and shore installations at Ube. The A /V tlak was m e a a e r aminaccurate. 17hile the heavy tlak ranged fran DlI8.gero intenae. Bothtypes of flak were inaccurate, as were 4 searchlight beams reported trCll1

ground installations, A /W 178S reported at Yoshimi (measer and 1mccurate).OneS/Luas also reported i.n this vici.nity. Heavyflak bursts (moderateard inaccurate) were reported at Ozuki am Ichinose.3. Over the target. both flak and sIL were more effectively usedthan previously noted on other targets over the Empire. All types at'I1eaponswere fired into an eIl.Vielopbarrage over the Straits area. Pre-dicted. fire 'only is believed to have been used on the outskirts at thetarget area. The target defense area may be roughly described as trian-gular in shape with the apex to the north at Futaoi Shima. Oneothercor-ner- to the east of Maji and the third at KanenoSaki (point of landuest of Ashira) Vlouldcomplete the t20iangle. In this area.. tlak wasreported from the emplacedweapons on land 'IIith the added fire power

of' lOO.nyanchoredaurf'ae e vessels. The barrage of flak. consisting ofboth heavy and med.iumcaliber weapons. was reported as intense andeff~ct1velY placed over the zone. The little predicted fire that couldbe lo~ated was inaccurate. Nevertheless, ifi the barrage over the Straits,2 am possibly 3 A le are believed to have been shot down. The mostaccurate flak 1s belieVied to have been delivered tram the vessels o t fWakam:ltsuarea a,nd the heavy guns on the islands of Fu.taoi, Ai Shimaand Shima.

4. Searchlights were effectively used, being first in actionon the east side of the straits approximately 5 miles off the coast.A systeJ1l,of lights turned on. with good accuracy. and carried the air-craft OVE'lr the land and intI'!)the mining area. Up to 30 ligllte werereporteil on the I{okure..Moji Peninsula from Sb1lnonoi;lekiand Hiko Islands.Cr ew e w er e able to pi~point the following locations on islands in theareal 5 S I L at 34106 - 130/473 S i t at 34/00 - 130/435 S/L at 34/01 .. 1 3 0 / 4 3 / 3 01sIL at 34/00/15 - 130/43/30'6 S I L at 33/59 - 130/49'4 S /L at 33/57 - 130/524 S/L at 33/56 .. 1301531 S/L at 33/57 - 130152


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5. A single barrage balloon (approximately 2000 teet) was re-ported on Ai Shima. There were no air-to-air or ground-to-air rocket.reported by the first gt"oup. The interesting observation w as m adethat 1airoraft, when coned by S / L ' s , would receive flak until theS / L ' s \7ere turned off. whereupon the flak would cease and night-fighter attacks were pressed. Desynchronizing engines thrEIIVott sIL'sonly about half of the times tried.6. The second and third Groups ran into the same fire as the

first Group, plus the fire t r a n the islands to the north. A sa i n , t h ebarrage was reported as efta,ctively placed and level in altitude.The heaviest concentration was encountered opposite Yawata atter cros-sing the Shimonoseki-Kaikyo Straits. The A /W fire.in th1B area. WUparticularly intense with manytracers observed. This was, far themost part I inaccurate. O f the second Group, 2 aircr~t o r 19 m i n . 1 n sthis area encountered no A lA fire over Yawata a1 l 272332X to 272335Xat 4900 and 5400 feet respectively. They did, hOlfever, while lay1namines 2 or 3 minutes later, observe flak in action behind than. Theremaining a m . following ai.rcraft ran through this tire over Yawataat 4900 to 5000 feet between the hours of 21233.5X and 280006X UJlderC A V U to 4/10 undercast and 8/10 overcast. OVerYawata the tollar1Dgwas also observed:

. a. At272356K.at4900 f,eeti'silver ~nd go~d_sprlrklea. dthno bursts, were seen. At 272357Kat 4900 l'ee1l, there were severalphosphorus bombs identified. At 280006Xat 4900 teet, a purple bUrstwas noted floating downon route out. In the vicinity of Fukuoka,several crews reported meager and iMccurate heavy aDdmediumflak.

7. The searchlights in and aroun.d Yawata and Shimonoseki werealso reported as ef1'eetive. They were capable of engaging aircrafta~oBt'~ediately after being turneffi on and, despite violent evasiveaction. could not be evaded. In the other areas. the lights were notof the same effectiveness. ApprOXimately 40 to 50 searchlights werecounted in and around Yawata, 10 to 1 5 at Shimonoseki. 5 at HikoIsland, 10 at Yu:lruhashi, 7 to 9 at Fukuolm. and 1 on Sada Misaki point.8, The next group on this same headingmad.e .somewhatsimiliarobservations. In addition, on the approach to the mainland prior t othe I.P the [ol1017i08 vus observed: from the vicinity of Saeki onthe eastern coast of K;yushu. fire appeared to be of heavy caliberalthough no mar'!!then 5 bursts wera observed. At Him.eShima. meagerA/if fire \'IIiS met. At Boru the A/Wtracers of meager intensity werealso seen. Certain of the aircraft minini the outer limits of thetarget' zone reeeived little or no flal


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Documents

21st Bomber Command Tactical Mission Report 47