North American B-25H-10-NA (S/N 43-5104) "Bones," the last H model built and last B-25 built at NAA's Inglewood plant, surrounded by P-51s. This aircraft was signed by factory workers and remained this way while assigned to the 81st Bomb Squadron, 12th Bomb Group, 10th Air Force. (U.S. Air Force photo)
The B-25H was an improved version of the B-25G. The fixed nose armament was increased to four nose-mounted .50-cal. machine guns and four more .50-cal. machine guns in fuselage mounted pods. The 75mm cannon was changed from the G model's M4 to the lighter T13E1 75mm cannon. The top turret was moved to the forward fuselage and the lower turret was removed and replaced by a single .50-cal. machine gun in each of the two waist positions. A tail turret housing a pair of .50-cal. machine guns was added bringing the firepower total to 14 .50-cal. machine guns and a 75mm cannon. The aircraft could also carry up to 3,200 pounds of bombs.
The prototype H model was modified from a block 10 B-25C and first flew in May 1943. This aircraft had improved Wright R-2600-20 radial engines, but all production aircraft were completed with the standard Wright R-2600-13 radials used on all B-25s since the -C model.
The first of 1,000 production B-25Hs first flight was on July 31, 1943. The five-man crew consisted of the pilot, navigator-cannoneer-radioman, flight engineer-top turret gunner, waist gunner-camera operator and tail gunner. Three of five crew members had multiple jobs; there was no co-pilot or bombardier and only one waist gunner. The last H model built was covered with the signatures of the North American Aviation factory workers and nicknamed "Bones." The aircraft remained this way throughout its combat life while assigned to the 12th Bomb Group in the China-Burma-India Theater.
Improved B-25G (more guns)
TECHNICAL NOTES: Armament: 14 .50-cal. machine guns and one 75mm T13E1 cannon plus 3,200 lbs. of bombs Engines: Two Wright R-2600-13 turbo-supercharged radials of 1,700 hp each (takeoff power) Maximum speed: 275 mph at 13,000 ft. Cruising speed: 230 mph Range: 1,350 miles Service ceiling: 24,800 ft. Span: 67 ft. 7 in. Length: 51 ft. 0 in. Height: 15 ft. 9 in. Weight: 33,500 lbs. (maximum) Crew: Five Serial numbers: 43-4105 to 43-5104 (B-25C-10-NA S/N 42-32372 modified to become the prototype B-25H)