Boeing XF6B

The Boeing XF6B-1 / XBFB-1 was Boeing's last biplane design for the United States Navy. Only the one prototype was ever built; although first flying in early 1933, it rammed into a crash barrier in 1936 and the design was not pursued further.

Ordered by the Navy on June 30, 1931, the plane was a derivative of the F4B; it was nearly entirely of metal construction, with only the wings still fabric-covered. It was powered by a 625 hp Pratt & Whitney R-1535-44 Twin Wasp.

The intended role of this design turned out to be uncertain. While its rugged construction was capable of withstanding high G-forces, it weighed in at 3,704 pounds (700 pounds more than the F4B), and did not have the maneuverability needed in a fighter aircraft. It was, however, suitable as a bomber fighter, and in March 1934 the prototype was redesignated XBFB-1 in recognition of its qualities. Even so, various ideas were tried to improve its fighter qualifications, such as improved engine cowling, streamlining around the landing gear, and even a three-bladed propeller (two-bladed props being standard).

References

• Lloyd S. Jones, U.S. Naval Fighters (Fallbrook CA: Aero Publishers, 1977, ISBN 0-8168-9254-7), pp. 115-117