UNCLASSIFIED

AD NUMBER

LIMITATION CHANGESTO:

FROM:

AUTHORITY

THIS PAGE IS UNCLASSIFIED

AD012886

Approved for public release; distribution isunlimited.

Distribution authorized to DoD only; Test andEvaluation; JUN 1953. Other requests shall bereferred to Naval Proving Ground, Dahlgren, VA.Pre-dates formal DoD distribution statements.Treat as DoD only.

NSWC notice dtd 9 Sep 1977

UNCLASSIFIED

AD NUMBER

CLASSIFICATION CHANGESTO:FROM:

LIMITATION CHANGESTO:

FROM:

AUTHORITY

THIS PAGE IS UNCLASSIFIED

AD012886

unclassified

restricted

Distribution authorized to DoD only; Test andEvaluation; JUN 1953. Other requests shall bereferred to Naval Proving Ground, Dahlgren, VA.Pre-dates formal DoD distribution statements.Treat as DoD only.

Controlling DoD Organization: Naval ProvingGround, Dahlgren, VA.

E.O. 10501 dtd 5 Nov 1953; Pre-dates formal DoDdistribution statements. Treat as DoD only.

THIS REPORT HAS BEEN DECLASSIFIED AND CLEARED FOR PUBLIC RELEASE.

DISTRIBUTION A APPROVED FOR PUBLIC RELEASE;

DISTRIBUTION UNLIMITED.

RESTS «s? •£

vn JWS$^-

u

BOMBS

S "AVAL PROVING GROUND

BAHLGREH. ViRG'HlA

REPORT m 113*

AND ASSOCIATED COMPORTS

%u* ?• '*l *• 9«po ?t

TEST OF .•* 77 MOO 0 BOMB (FIRE-7S0 LBS) WITH CANTED FIHS

T«»k PIIAl • • »0 11 *i * i $««•«• if S *• Ic 321-i S3

Ce*y BO Ci•t » i 1 • c »tion ItSTlHCn? t ""IITY lflf9««»T 121

o o NF3 REPORT NO. H36

Teat of aik 77 Lod r Boeb (Plre-750 Irs.) -lth Canted Pins

1. This Is the final report on tests T>«rforced on the Lk 77 Kod 0 Boob (Flre-750 lbs.) equipped with canted fins.

2. Tests v**re conducted or. the boab to determine*

a. Fit on ell applicable station? of avtliable service tyoe aircraft.

b. Flight characteristics of bomb and plane combination.

e. Separation coaractcri?ti~r In drops.

d. Free flight stability.

•• Tins of fall.

f. Spinning rate.

g. Creterlng characteristics,

h. Functioning characteristics of fur*-,

i. a>inroxlaate spread of bomb contents.

3* It was determined thatt

a. The bonb fits satisfactorily on ring end center stations of the P7F-}, the »lng racks of the *D-2, am the oort and starboard pylons of the F*U-> provided that no more than 70 derrees of flaps -».re used.

b. There Is apparently nc vibration la flitht. and there Is no appreciable defoncetion of the bor.b other tv.er. a slight twisting between the sections at speetfs u to 300 knots.

d. Flight stability is excellent.

UCUHITY IXPtataXICH

c. The bomb ser-arates cleanly -hen dro-»red frosj the P4B-5 end «1>*2 aircraft •

)

HPG liSPORT HO. 1136

last of Kk 77 Kod 0 Boob (Firo-750 lbs.) rith Canted Fins

o* Time of fall fro© 3500 fret and ?50 knots Indlectcd airspeed In horizontal flight Is approximately 13.5 seconds. Tlao of fall fro* 3500 foot and 250 knots elrspoed In a dive of approximately 60 degrees it nine (9) seconds.

f. The spin reached a maximum of 923 r.p.m. Just prior to impact for the horizontal drops, and -as approximately 600 r.p.m. for the living drop Just prior to Impact.

g. The average dimensions of the crators rere approximately five (5) fi-ot deep by oipht (8) feet In diameter.

h. One (1) of the two (2) fuzes recovered (tall fuze on drop numbor 3) did not arm although the arming wire had pulled free, The other fuse (nose fuse on the diving drop) had armed and would havo flrod.

1. Spread varlod from 20 to 60 feot forward of the crater and was 10 to 20 foot wide respectively for the horizontal drops. The dive drop had a spread 60 foot long. At 30 fret ahoad of the crater, the spread was 40 foot across. The shape of the sprced resomblcd a diamond, with the rherp point at the crater.

4, Conclusions!

a* The bomb ^-ulppcd rlth canted fins has a high rato of sMn and excellent flight stability.

b. Tho tall fuse recovered ild not arm either bocauso of bomb spin or lack of air flow past the arming vanes In the recessed well.

5. RoeommendetIonss

It Is recommendod that the of feet of bomb spin on arming vanes of fusts located along tho contorltnt. of the bomb be Investigated. This spin acting in the same direction of rotation of tho arming vans' action in rrain>; the faze may prevent arming from taking place It is further rocorat \dod that live drops be eedo to provide noro definite Information as to spread of the napalm gel since the inert mixture us-d Is difficult to ace and scasurc against earth.

bJCl.'.ITY liTrX-.XaTICII

KPG REPORT KQ. 1136

?«st of Kk 77 Mod C Boafe (Pir*-?50 lb?.) **ith Stated Plna

I*Q* g SfigfflSfi

gyscpsis . . , 1

t^ld OF CC?*T-OTi> 3

AOTHOiiJTY 4

aEFSREKCES 4

BUJCKGROUKB 4

02-J2C7 OF »* 4

P£UOD GF TEST 4

RiPSJSSSI.iJIVS P^ESEHT .... 9 * 4

DS&2RIPI20H CF 1231 UKl/SR TEST . 5

-SfeCRIPtlCH OF T^T i-pIPim:*! , , . . 5

.'ROCKXiRl 5

R£&TLrS *JfD j>2SCU55IOH . • 6

JOMCLU^IOHS 7

aBCCKk^ffijuncss 7

APPEXDIX A - :TC PKCTOURiJ>::s Pi'UHSS 1-11 (Incli

imams - tsaansusm TEST DATA I/JJLES I-IV (inci)

A??3?:MX C - DISTftlEUTICS .1-2 (In^l)

&8CCMTY I :iPC*\i UII OK

\

( ) 0

j RESTRICTS) !JPG aBVCRI NO. 1136

Tctt of mc 77 Mod 0 Bce»b (?ir-5-7SO lb?.) *ith Cmt-i Fins

Pi3T L

laaaacafia

!

1. AUTHORITYI

Thuso tosts were authorized by reference (a) and conduct.-.d urJor Task Asslfflsscnt HPO-Bc3c-321-1-53 established by rcforenco (b).

2. BJr^l£TCa^S

a* Bt'CJ) Rost ltr Ro3c-R3*»gg P41-6 of ?4 Ltr 1953 b. BUQIiB Conf ltr HP9 Re3c-^£Kf»p 5-r 42777 of 29 Jul 1952 c. JUVF20Y ltr OVXt'^hKf.sc All/3« 321-1 S>r 30596 of

25 Fob 1953 to BOORS 4* FOmCOff b.t^'in LT E. 3. liouton, IJPG, and

Mr. R. B. Hl^dcritrasacr, PtC.iD. on 1 JJT 1953 e, RFC R^ort Ro. 838 of 28 ,»ug 1951

3. OACKGRODRDi

In order to Improve the spread of fcl on Bcdlus altitude rolecs ost attempts have been made to spin tho fire bcer« Erratic results rorc obtained fTom attempting to spin tha bomb by attaching tabs to the fins* These tests *oro reported In rcfrrencc (c)» The canted fins warm developed In an effort to obtain moro reliable rpln and to improve th* stability of the spinning bomb.

4. OBJKCT OP TtSTt

The object of the tost is to dotcrmlnc the feasibility of spinning a fire bosib by tens of cent d fins to isnrovc its oven 11 cffeetivc.vjs* vhon droppod free 3500 feet in horizontal end divo altitudes.

5. PERIOD or resit a* Data Project Letter b. Date katerial Received c. Dato CoMsoneed kodlfyinf Fins d. Date Commonccd Tests o. Date Cosiplttcl Tests

6. RSPHSSaCTATlYl PHBSKtfTi

h. fc. Sludarstrass r

24 Lerch 1953 ->4 Warch 195 3

1 April V>53 16 Anril 1953 ?.& April 1951'.

Bureau cf Orir.: nee

RSSTHICTiD SSCV.tIT: 2!iFC-JUi:iK

RSSTftlCTB) XPG REPORT KC. 1136

Tort of Mk 77 Mod 0 Best CFIrc-T^O lbs,) rith Canted Fins

2&J

?. DESCIUPTICS OF ITBS USBER TEST*

The bomb tested was & standard Ilk 77 Uod 0 Boob (Firo-750 lbs.) inert loaded and equipped *dth inert H23 Igniters and inert 11173 Fuses and further equipped rith Modified cantad fins instead of the standard fins or fins rod shrouds. The noso and tail cones rore not installed* The fins are manufactured of ST aluminum, 3/16 Inch in thickness end 18 inches in length along the root chord* Tho fins •~«ro roldee at an angle to an adapter which bolted to tha boob. The anflo of fir* to the fore and aft cent or line of the bomb, and to the adapter, is about 10 degrees. Actual measurements are given in Table I* Reference Cc) authorised the modification of the fins as follows* the fins were stronfthcncl by bolting a 3/8 inch stool rod 1-1/2 inches down and in from the outboard after corner of two (2) adjacent fins, and bolting rods between the next two (2) fins as close at practice! to the bolts used in the first two (2) fins. Figures 1 through '4 show the bomb before-«n5' after modification.

8. D£&CaiPTRX OF TSCT ZrjJXPIiSNTl

a* The follorini aircraft were usods F7F-3, AD-2, and F4U-5*

b. 4 Litchcll chronograph camera oqui^ood idth a 40 inch lens.

9. PKCCSWJKS.

a* Assembling

iTm BWBI r-jrv asi'Vajtil.'^ without fiOsu Or tc.ii Ci»in. s. 1 fi'i the crnted tins *erc modified. Inert U23 Irnitcrs and inert HI73 Fuses were instilled.

b. Fit fasts

Tarn following aircraft ware us*rl for these testsf F7F-3, AD«2t and ?4tf-5. Cn the ¥7T-} and *D-2 aircraft, the bomb was hung o« the center rack and one (1) wing rack. (The center rack of the F7F-3 has bean changed at this activity to 1 Uc 51 -od 11 Back. This is nsot standard equipment.) On the F41-5, the bomb was hung on omi (1) pylor. rack. Th* landing flaps w<?re actuated on all airertft.

.<&& fiiict SD

RESTRICTED NPL 3SP0RT HO* 1136

Test of kk 77 Eod 0 Bomb (?ire-?50 lb-,) wit!> Canted Pins

c. Flight Tests

One (1) boob was loaded rith water containing a snail ajgoistit of fluorescent dye. The purpose of the dye was to give visual proof of any tendency of the bomb sections to separate or warp. This separation or warp might be caused by the canted fins twisting the after section of the bomb while the middle section wes held rigid by the bomb rick and sway braces.

d. Aircraft Drop Tests

Four (4) bombs ?*ere inert loaded to weight with a dry fixture of granulated cork and Portland cement. Inert H23 Igniters and K173 Fuses were installed, Three (3) bombs *ere dropped frets the F4U-5 aircraft in horizontal flight at an altitude of about 3500 feet and 250 knots indicated airspeed. ¥tm fourth bomb was drooped from an AD-2 aircraft in a dive of 60* from 3500 feet and 250 knots indicated airspeed. Motion picture coverage of release, flight, and impact data was made with a Mitchell chronorr&ph camera equipped vith a 40 Inch lens.

10. B2SULXS tm DISCUSSIONS

The modification of the Kk 77 Mod 0 ?lre Bomb to take canted fins does not differ materially in fit or flight tests from the standard Kk 77 Kod C Fire Bomb as reported in reference (e). The canted fins and strengthening thereto do rvv?- cause additional interference on the aircraft on which fit tosts rere conducted. The F4U-5 cannot carry the bomb when *<iare than ?0 degrees of flaps are used. The bomb interferes with oil cooler door operation on the AD aircraft, and thcrofore cannot be carried operationally on the bom?- ejector rack. Behavior of the modified bomb in flight tosts vas the same as that of the unmodified bombe Results of fit and flight data ars present'4 in Table II and Table III, respectively. The canted fins provide the «k 77 Nod 0 Bomb with a vory stefclo and saioDth flirht. The canted fins cliainatc the erratic spin and instability heretofore encountered in attemptin^ to sake the fire bomb spin, but the results of this tests sro inconclusive as to the effectiveness of increasing naptls «tprc&<*. Drop data is riven in Table IV. The tail fuse recovered from bomb number 3 v»* disrcsomblod &nd shored that although the arming *"irc had pulled free, the fuse had failed to arm. A possibility f,*ista that the fu*o was not pre-crmed by rot at lorn of the arming van- one (1) full turn. Iiepcet forces • re sigh enough to Jca thv firing pin sleeve ptst the s&fo position end Into & V* fired position. Figures 7 through 11 show the fuse- and relative positions of the firing pin and sloovo in the full safe

'position uad cs found. •

SICKiITY. irTC^^ICN 6

RBSTBJCT2E KPG RSPGttt NO. II36

Test of Kk 77 Kod 0 Bomb (Firc-750 lbs.) ^ith Centcd Pins

£iSO

SSKUBOm

11. Sottuso of fit problems, tho Kk 77 Mod 0 Fire Bomb with centcd fins e&nnot be used by F40 squadrons operating at sea. Tho ftr and pitch of tho bcab encountered in the drop mado in tho 60 degree divo and referred to in Table IV could have been caused by the aircrnft being in a skid upon release of the bomb. Position of the cameras t&i imch that the condition could neither be proved nor disproved by film assessment. Fuze arising action in the tail of the Uk 77 Mod 0 Fire Bomb is not positive, nlr flow over the tail cone nay be turbulent and of insufficient amount to cause the arming vane to rotate to the completely armed position. The effect of bomb spin on vane action may be such as to prevent arming. There does not appear to be any difference in the size of the crater made in horizontal drops free that made in a high anrle release from the same altitude and airspeed* It mas noted that most of the bomb and the nose fuze bounced out of the crater and landed approximately 20 feet ahead of the crater in the dive bemsirsg drop. This effect might have been caused by spongy serth. The etrth was soft and vet near the surfaces

P*3T S

1?. It is recommended that live drops be made to obtain accurate spread measurements in both horizontal end dicing releases. It ii further recommenied tnat bomb spin effect on ceuterliui mounted futos be Investigated.

0 ii RESTRICTED KPG .1BPGRT HO. II36

Tart of Hk 77 Mod 0 Bomb (Flre-750 It?.) rith Crr.tcd Pir,a

Tba tests upon which this reoort is based TTOTC ror.ducted by: B. B. KGUTCH, Lieutenant,'USN

Assistant Aircraft Ordnance Stores Officer Aviation C.Hnance Department

This report was prepared by: S. £. HCJTOH, Lieutenant, USN

Assistant Aircraft Ordnance Stores Officer Aviation Crdr.ap.co Department

This report was reviowed byx J. ft. PBfTZRS. Hoad Engineer

Aircraft Ordnance Storos Division Aviation Ordnance Department

R. ?. LYNr, Llcutonant Commander, US.*: Aircraft Crdnanc; Stores Officer Avlttlon Ordncnc- Department

J. C. TAJ.I.KY, Director of Rcs-.-rch Aviation Ordnance Department

J. D. VaXSGlv, Lieutenant Commander, USH Assistant Aviation Ordnance Officer Aviation Ordnanco Dvpartornt

P. A. JRJSOk, Crptr.in, JSH Aviation Ordntnco Officer Avictlon Ordi^ncc Department

C. C. BRAi7,L£, Director of Rcaocrch Orinrnco Crou^

A<>?R0VEDS Ccpttln, us.n Coawcr.der, Hcvul Proving Ground

A. ft&CKMSt Captcin, US* Ordn&nco Officer By direction

PJSTniCTiS -> xir.i; n 1 MrO« AT 1 c 5

RESTRICTED HPC K2PCflT 80. II56

U, l%. X.VJLL ?RC¥I!1G GROUTS DAKLGR£**, YIRGIHIA

Sixty-Second Pcrtit.1 Report

on

Lonbg and A^socict.cl Coocnonts

Finr.l Koport

on

Tcit of UX 77 ttod 0 Boob (Flro-750 lbs.) with Cnntod Flna

JUN 8- 1953 Preset S0.1 8H»-R 3c-321-1-53 D«*°i go. ef Vtg as* 8

Rssmicrso

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ac pi *

coo I tttfSi

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m

o o "BBEThlZTSS)

Teut of m 77 Mod C goofe

RFC SSPOS7 SO. 1136

(Flp»-750 lb«.) with CAnt^J Fin*

XABUUL

AKLE Of FI* a ES3 A!P AFT :BM7ESLIK8 OF BOMB

Drop So«

1

2

3

4

Toy Mite Pin

10*

9*

MJi&JUfi 9°

8°

10*

n« 9*

10s

9#

11#

11°

«rr?sixrnD APP^T'U S

Q O

WSS7XLCW) IFG R2P03T HO. 1136

TMt of m T7 Hod C Beab (Fire-75C Ibe.} with Canted Fins

2IBU2

m rare at naaiB

typo Aircraft

Station and Hack oi

AT •-? Starboard Wing ft 51-11

4-1/2 inches clearance frca rod to flap. Ho interference hetssen flap and find,

.J5-2 Canter Douglas Bcssb Ijector

3 inch clearance be- tween ro? and fuselage. Oil cooler door opens only 1/4.

FAU-5 Starboard p?lon Mc 51-11

L inch clearance bo- tanen fin and deck. Flap* interfere at 20*.

F7F-3 Port Winf Mk 51-11

Ho interference and sufficient olearanoe.

F?F-3 C*r,»-sr ft 51-11 (Hot standard •qui patent)

1/2 in -h clearance bo- taroen rod and fueolege.

Clearance Satisfactory

Interference between noee eectlon of boab and oil cooler door. Ubsatiifactory.

Unsatisfactory at any tine sore than 20* flepe are needed.

Satisfactory.

Satisfactory. Roto that U inch •uspensien ie not standard oqulpaont for this station.

X'TtXill 8

wummsRtUji-

§ •

msttacim BPG HBTORT no. U36 Test of * 77 led 0 9orb Jfiro-75C lbs.) with Canted Pins

X&BI&JJ2

FLIGHT TSSW « AMCltfT

T*»

AD-2

AD-2

Tiw/iirnpeod

lo/aoc

15/22 £3

A2-2 15/230

AD-2 15/2»

F7T-3 S/KC

Modiua leek between aft and aid sections at bottoe of boat). Connecting rod nose nut opening ooaaonnsd leaking.

No leakage between aft <md aid sections. Slight leakage between forward and aid sections along bottom of boob.

Slight leaks between aft, aids and forward sections. Rose nut eontlouod leaking.

Slight laak between aft and aid section. Rose not continued leaking.

Very slight leak at nose nut. All other leaks Stopped.

SET.'KITT mom rim A°?«*KDII B

\ / ~**w

wrmcrm mo FK?ORT SO. 1136

Twst of 3k 77 Mod 0 Bos* (Firs-750 lbs.) with Cantod Fin*

DBOP DATA

lias of Drop Tyjxj Date Rsloaas Alt (ft)/ Flight Xspact Siu. Adrift 1222 Air^.od (kts) .SiSSL SSl&J^M SSS&i

1 F4U-5 4/16 3500 ft/250 kta 13.5 923 rpn Borls^tal flight Sxceilsat stability

2 FA0-5 4/17 3500 fi/250 kt* — 750 rpa Borisontal flight Szcollont stability

3 F40-5 A/1? 3200 ft/200 kts 13.5 793 rpss Horisoetai flight Excellent stability

S@« Not* #1

I AD-2 4/24 35CC fV250 kts 9 600 rpm 60* Wft - Slight yw *ad pitch throughout night.

S^Ti Is Aircraft pilot dsclared an oaorgeosy, and although originally scheduled as a diving drop, tha bomb as* ralsassd 1st heri aortal flight as pilot roturaad to base.,

wrruff uronunoi AP^SSIDII B

! > o SPG HEPCRT i*K). U36

Tost of Kk 77 kod 0 Scab (Firc-750 lbs.) rit'.i Ctntcd Fins

DISTRIBCTIOK

Burccu of Ordnance A43 1 Ao3 1 Ro3c 7

Director, Araed Services Technical Infonattion Agency Doeuront Service Center Knott Building Dayton ?, Ohio 1

Coemandlnf General, Aberdeen Proving Ground Aberdeen, Maryland Attnt Technical Information Section

Development and Proof Services 1

Cr—inler, Operational Development Force, U. S. Atlantic Fleet| U. S. Naval Bate, Norfolk 11, Virginia 1

*rvy Research Section, Library of Contrast Washington ?% D. C, (Via WORD Raj) ?

.•'oval Gun Pcctory 1

Naval Gun Factory Attni aircraft araaaent Section 1

Bureau of aeronautics f.t-ni Ai«ae«nt Section 2

KATC, Petuxent Hi?er, Maryland 3

Kavel Auxiliary Air Station Chlncoteague, Virginia 1

air material Cowiar>d Litison Officer ting 3 Keadiuarters, Aberdeen Proving jrou?>d, Aberdeen, Maryland 2

Kaval Liaison Officer LGAFP^C, 6gim FieiJ, Florida *

Z~~:7IT-: T:;/c :**::<: ?: 1 *p?ea>ix C

k

O BPO RXPCRT NO. 11^6

Test of Mk 77 Mod 0 Boat (Flre-750 lbs.) *Ith Canted Fine

MfiTIIIBCTICK (Continued)

HOTS, Inyokern, California 1

•aval air Development: Cantor, JohnsvUle, Pennsylvania 1

U. S. air Force, AtfC Enfineering Field Office AOOS1 1?33, Main Hivy Building lavy Department, Washington, D. C. 2

Cn—andlnc General Air Force Aimajtent Conter Iglia air Force Bate, Florida attni technical Library l

Officer, Picetlnny kricnal Dover, Hoe Jersey *ttnt Technical Division

Ci—smiling Officer Plestlnny Arsons! Dover, Hew Jcrsay jkttni Technical Dlvlslon-Boo© Unit

Loculi OV } ovx } File l

, lSyOUUTICR ? *J»F?.:©ix w