PBJ-1 for US Navy

Last revised March 11, 2000


The PBJ-1 was a navalized version of the USAAF B-25. It had its origin in a deal cut in mid-1942 between the Navy and the USAAF. The Navy was anxious to acquire a long-range, land-based heavy maritime reconnaissance and patrol aircraft capable of carrying a substantial bombload, but the USAAF had always resisted what it perceived as an encroachment into its jealously-guarded land-based bomber program. However, the USAAF needed an aircraft plant to manufacture its next generation of heavy bombers, the B-29 Superfortress. It just so happened that the Navy owned a plant at Renton, Washington, which was at that time being operated by Boeing for the manufacture of the PBB-1 Sea Ranger twin-engined patrol flying boat. The Army proposed that the Navy cancel the Sea Ranger program and turn over the Renton factory to them for B-29 production. In exchange, the USAAF would get out of the antisubmarine warfare business and would drop its objections to the Navy's operation of land-based bombers and the Navy would get "navalized" B-24 Liberators, B-25 Mitchells, and B-34/B-37 Venturas for use in maritime reconnaissance and antisubmarine warfare. The Navy readily agreed to this arrangement.

As part of the deal, fifty B-25Cs and 152 B-25Ds were transferred to the Navy from the USAAF. They were assigned the designations PBJ-1C and PBJ-1D respectively. The designation suffix of these and all subsequent PBJ-1 variants corresponded to the suffix of the corresponding B-25 model. The planes carried Navy serial numbers beginning with 34998. The first PBJ-1s arrived in February 1943. They were used by Marine Corps pilots, beginning with VMB-413. Many of them were equipped with a search radar with a retractable radome fitted in place of the ventral turret.

One B-25G was delivered to the Navy as PBJ-1G BuNo 35097.

Large numbers of B-25H and J variants were delivered to the Navy as PBJ-1H and PBJ-1J respectively. These aircraft joined, but did not necessarily replace, the earlier PBJs.

The PBJs were operated almost exclusively by the Marine Corps as land-based bombers. To operate the PBJ-1s, the US Marine Corps established a number of bomber squadrons, beginning with VMB-413, in March of 1943 at Cherry Point, North Carolina. Eight VMB squadrons were flying PBJs by the end of 1943, forming the initial Marine Medium Bombardment Group. Four more squadrons were in the process of formation in late 1945, but had not yet deployed by the time the war ended.

PBJ-1Hs served with VMB-412, VMB-413, VMB-423, VMB-433, VMB-443, VMB-453, VMB-463, VMB-473, VMB-483, VMB-611, VMB-612, VMB-614, VMB-621, VMB-622, VMB-623, VMB-624. VMB-413, 423, 433, 443, and 611 operated in the Central and South Pacific, and BMB-612 and 613 operated in the Central Pacific.

Operational use of the Marine Corps PBJ-1s began in March of 1944. The Marine PBJs operated from the Philippines, Saipan, Iwo Jima and Okinawa during the last few months of the Pacific war. Their primary mission was the long range interdiction of enemy shipping that was trying to run the blockade which was strangling Japan. The weapon of choice during these missions was usually the five-inch HVAR rocket, eight of which could be carried on underwing racks. Many of the PBJ-1C and D versions carried a rather ugly, bulbous antenna for an APS-3 search radar sticking out of the upper part of the transparent nose. On the PBJ-1H and J, the APS-3 search radar antenna was usually housed inside a ventral or wingtip radome. Some PBJ-1Js had their top turrets removed to save weight, especially toward the end of the war when Japanese fighters had become relatively scarce.

In mid-1945, VMB-612, based on Iwo Jima, flew specially modified PBJ-1Js capable of carrying the 11.75-inch Tiny Tim rocket. Two Tiny Tim rockets could be carried, one on each side of the fuselage above the bomb bay doors. Launch was by free fall, and ignition was actuated by a lanyard that was pulled after the rocket had dropped a certain distance. After launch, the bomb bay doors could be opened for conventional bomb drops. These Tiny Tim rockets were used during nighttime strikes against southern Japan in the interim between the dropping of the second atomic bomb on Japan and the final agreement of surrender on August 14.

In 1945, the Naval Ordnance Test Station at China Lake, California carried out a joint program with the Harvey Machine Company for the development of an automatic launcher for five-inch spin-stabilized rockets from the nose of a PBJ-1J. Two rotating drums carried five spin-stabilized rockets each. The rockets could be released in salvoes of five or singly at 3/10 sec intervals. A deflector tube ported the blast from the rocket exhaust downward out of the airplane at the aft end of the nose section. PBJ-1J 35849 (ex USAAAF 44-30980) was selected as a test aircraft for the program. Ground and aerial firing tests failed to prove the concept sufficiently effective to warrant production.

PBH-1H 43-4700 (BuNo 35277) was modified for aircraft carrier catapult launch and arrest retrievals. The first landings and catapult takeoffs took place aboard the USS Shangri La (CV-38) on November 15, 1944. Although the experiment was successful, no further work on a carrier-based Mitchell took place since American advances in the Pacific made such an aircraft unnecessary.

Navy (as distinct from Marine Corps) use of the PBJ-1 was limited to a few aircraft being used after the war for test and development work up to 1948.

The following is a list of serial numbers of USAAF B-25s turned over to the US Navy as PBJ-1s:

41-30533/30847		North American B-25D-20 Mitchell
				30730/30754 to USN as PBJ-1D 35048/35072
42-64502/64701		North American B-25C-20 Mitchell
				64502/64506 to USN as PBJ-1C 34998/35002
				64602/64621 to USN as PBJ-1C 35003/35022
42-64702/64801		North American B-25C-25 Mitchell
				64708/64732 to USN as PBJ-1C 35023/35047
42-64902/65101		North American B-25G-5 Mitchell
				65031 to USN as PBJ-1G 35097
42-87138/87452		North American B-25D-25 Mitchell
				87157/87180 to USN as PBJ-1D 35073/35096
				87181/87205 to USN as PBJ-1D 35098/35122
43-3280/3619		North American B-25D-30 Mitchell
				3320/3344 to USN as PBJ-1D 35123/35147
				3570/3605 to USN as PBJ-1D 35148/35183
43-3620/3869		North American B-25D-35 Mitchell
				3651 to USN as PBJ-1D 35184
				3655 to USN as PBJ-1D 35185
				3771/3778 to USN as PBJ-1D 35186/35193
				3837/3843 to USN as PBJ-1D 35196/35202
43-3870/4104		North American B-25J-1-NA Mitchell
				3985,3986 to USN as PBJ-1J 35194,35195
43-4405/4704		North American B-25H-5 Mitchell
				4471 to USN as PBJ-1H 35280 
				4482 to USN as PBJ-1H 35281 
				4492 to USN as PBJ-1H 35282 
				4530 to USN as PBJ-1H 88872
				4542/4544 to USN as PBJ-1H 35283/35285 
				4591/4593 to USN as PBJ-1H 35286/35288 
				4638 to USN as PBJ-1H 88873
				4654 to USN as PBJ-1H 88874
				4655 to USN as PBJ-1H 35292 
				4656 to USN as PBJ-1H 35259 
				4658 to USN as PBJ-1H 35293 
				4659/4660 to USN as PBJ-1H 35250/35251 
				4661 to USN as PBJ-1H 88875
				4664/4666 to USN as PBJ-1H 35294/35296 
				4667 to USN as PBJ-1H 35252 
				4669 to USN as PBJ-1H 35253 
				4670 to USN as PBJ-1H 35260 
				4671/4673 to USN as PBJ-1H 35254/35256 
				4675 to USN as PBJ-1H 35261 
				4676 to USN as PBJ-1H 35257 
				4682/4684 to USN as PBJ-1H 35289/35291 
				4685/4702 to USN as PBJ-1H 35262/35279 
				4703 to USN as PBJ-1H 88876
				4704 to USN as PBJ-1H 88877
43-4705/5104		North American B-25H-10 Mitchell
				4705 to USN as PBJ-1H 89051 
				4709 to USN as PBJ-1H 35297 
				4710 to USN as PBJ-1H 35258 
				4711/4883 to USN as PBJ-1H 88878/89050 
				5028/5047 to USN as PBJ-1H 89052/89071 
43-27473/27792		North American B-25J-1 Mitchell
				27511/27515 to USN as PBJ-1J 35203/35207
				27681/27687 to USN as PBJ-1J 35208/35214
43-27793/28112		North American B-25J-5 Mitchell
				27904/27910 to USN as PBJ-1J 35215/35221
44-28711/29110		North American B-25J-15/17 Mitchell
				28792/28801 to USN as PBJ-1J 35229/35238
				29064/29073 to USN as PBJ-1J 35239/35248
44-29111/29910		North American B-25J-20/22 Mitchell
				29276 to USN as PBJ-1J 35249
				29277/29285 to USN as PBJ-1J 38980/38988
				29290/29299 to USN as PBJ-1J 38989/38998
				29510/29513 to USN as PBJ-1J 64969/64972
				29604/29617 to USN as PBJ-1J 38999/39012
				29618/29623 to USN as PBJ-1J 64943/64948
				29788/29794 to USN as PBJ-1J 64949/64955
				29801/29807 to USN as PBJ-1J 64956/64962
				29814/29819 to USN as PBJ-1J 64963/64968
				29870/29884 to USN as PBJ-1J 64973/64987
				29897/29901 to USN as PBJ-1J 64988/64992
44-29911/30910		North American B-25J-25/27 Mitchell
				30353/30356 to USN as PBJ-1J 35821/35824
				30509/30531 to USN as PBJ-1J 35798/35820
				30703/30710 to USN as PBJ-1J 35830/35837
				30716/30718 to USN as PBJ-1J 35838/35840
				30849/30851 to USN as PBJ-1J 35877/35879
				30856 to USN as PBJ-1J 35880
44-30911/31510		North American B-25J-30/32 Mitchell
				30961/30964 to USN as PBJ-1J 35841/35844
				30972/30975 to USN as PBJ-1J 35845/35848
				30975 (BuNo 35848) converted into prototype
				for trainer.  w/o 3/25/1950
				30980/30991 to USN as PBJ-1J 35849/35860
				31089/31104 to USN as PBJ-1J 35861/35876
				31277/31296 to USN as PBJ-1J 35881/35900
				31444/31463 to USN as PBJ-1J 35901/35920

The following is a list of the BuNos of Navy PBJ-1s, with USAAF equivalent serials:

34998/35047		North American PBJ-1C Mitchell
				Navy equivalent of B-25C
				were USAAF 42-64502/64506,42-64602/64621,
				42-64708/64732
35048/35096		North American PBJ-1D Mitchell
				Navy equivalent of B-25D
				were USAAF 41-30730/20754,42-87157/87180.
35097	 		North American PBJ-1G Mitchell
				Navy equivalent of B-25G (42-65031).
35098/35193		North American PBJ-1D Mitchell
				Navy equivalent of B-25D
				were USAAF 42-87181/87205,43-3302/3344,
				43-3570/3605,43-3651,43-3655,43-3771/3778
35194/35195		North American PBJ-1J Mitchell
				Navy equivalent of B-25J
				were USAAF 43-3985/3986
35196/35202		North American PBJ-1D Mitchell
				Navy equivalent of B-25D
				were USAAF 43-3837/3843
35203/35249		North American PBJ-1J Mitchell
				Navy equivalent of B-25J.  Were USAAF
				43-27511/27515, 43-27681/27687,
				43-27904/27910, 43-28174/28180,
				44-28792/28801, 44-29064/20073, 44-20276
35250/35297		North American PBJ-1H Mitchell
				Navy equivalent of B-25H
				were USAAF 43-4659/4660, 43-4667, 43-4669,
				43-4671/4673, 43-4676, 43-4710, 43-4656,
				43-4670, 43-4675, 43-4685/4702, 43-4471,
				43-4482,43-4492,43-4542/4544,43-4591/4593,
				43-4682/4684,43-4655,43-4658,43-4664/4666,
				43-4709.	
35798/35920		North American PBJ-1J Mitchell
				Navy equivalent of B-25J.  Were USAAF
				44-30509/30531,44-30353/30356,
				44-30693/30697,44-30703/30710,
				44-30716/30718,44-30961/30964,
				44-20972/30975,44-30980/30991,
				44-31089/31104,44-30849/30851,
				44-30856,44-31277/31296,44-31444/31463
38980/38999		North American PBJ-1J Mitchell  
				Navy equivalent of B-25J. Were USAAF
				44-29277/29285, 44-292290/29299,
				44-29604/20617.
64943/64992		North American PBJ-1J Mitchell
				Navy equivalent of B-25J.  Were USAAF
				44-20618/29623, 44-29788/29794, 
				44-29801/29807, 44-29814/29819,
				44-29510/29513, 44-29870/29884,
				44-29897/29901.
88872/88999		North American PBJ-1H Mitchell
				Navy equivalent of B-25H.  Were USAAF
				43-4530,4638,4654,4661,4703,4704,
				4711/4883,4705,5028/5047

Sources:


  1. B-25 Mitchell: The Magnificent Medium, N. L. Avery, Phalanx, 1992.

  2. Medium with the Mostest--The B-25 Mitchell, Jerry Scutts, Air International, Vol. 44, Nos 2 and 3, 1993.

  3. Boston, Mitchell, and Liberator in Australian Service, Stewart Wilson, Aerospace Publications, 1992.

  4. Famous Bombers of the Second World War, William Green, Doubleday, 1959.

  5. North American's Flying Gun--The Story of the B-25 From Paper Airplane to Legendary Bomber, Jack Dean, Wings, Vol 23 No 4, 1993.

  6. United States Military Aircraft Since 1909, Gordon Swanborough and Peter M. Bowers, Smithsonian, 1989.

  7. United States Navy Aircraft Since 1911, Gordon Swanborough and Peter M. Bowers, Naval Institute Press, 1990.

  8. North American B-25A-G Mitchell, Aircraft in Profile, Doubleday, 1966.

  9. Jane's American Fighting Aircraft of the 20th Century, Michael J. H. Taylor.