The XB-38 was a modification project, done by Lockheed Vega, on the 9th Boeing B-17E (S/N 41-2401) built. Vega proposed, in March 1942, to convert a B-17 airframe by replacing the standard Wright R-1820 radial engines with Allison V-1710 'Vee' engines. In July, the Air Corps approved the project (AC-28120). In addition to the new engines, the aircraft featured a larger fuel capacity and full-feathering propellers.
The XB-38 project was initiated primarily to try to improve on the overall performance of the basic B-17 and to provide an alternate version in case the Wright R-1820 radial engine became scarce. The Vega Airplane Division of Lockheed received the B-17E and intended to use it as a pattern source for an all new design. Serial number 42-73515 was reserved for this design, but because of the urgency of the project, the B-17E was used and the new design was never completed.
The modifications on the -E model took less than a year to complete and the aircraft made its first flight on 19 May 1943. Initial performance tests showed the aircraft to be slightly faster than the production B-17E. The XB-38 was grounded after a few flights because of a serious problem with leaking engine exhaust manifold joints. After this problem was fixed, the test program continued until 16 June 1943 and the XB-38's ninth test flight. On this flight, the right inboard engine (#3) caught fire in flight. The test pilots were unable to put the fire out and bailed out. The resulting crash destroyed the XB-38. All future plans for the XB-38 were dropped because the V-1710 engines were needed for higher priority projects.
TYPE
XB-38
Number Built/Converted
1 (cv)
Remarks
B-17E with V-1710-89 engines
Notes:
Serial number: 41-2401 (42-73515 reserved but not used)
First flight was on 19 May 1943
Aircraft destroyed in a crash on 16 June 1943
SPECIFICATIONS
Span: 103 ft. 11 in.
Length: 74 ft. 0 in.
Height: 19 ft. 2 in.
Weight: 64,000 lbs. (max. gross weight)
Armament: One .30-cal. and eight .50-cal. machine guns plus 6,000 pounds of bombs.
Engines: Four Allison V-1710-89 engines of 1,425 hp. each at 25,000 ft.
Crew: 9 (max. as designed) Tests usually conducted two just a pilot and copilot.
PERFORMANCE
Maximum speed: 327 mph. at 25,000 ft.
Cruising speed: 226 mph
Range: 1,900 miles with 6,000 lbs. of bombs (estimated); 3,600 max. ferry range
Service Ceiling: 36,600 ft.