The Huff-Daland XB-1 was the first U.S. aircraft assigned a Bomber (B) designation. The Army Air Corps began naming bombers using just "B" in 1926, dropping the HB scheme soon after and the LB scheme in 1930. This new scheme continued through 1962 when the naming of U.S. military aircraft was revised and simplified. The Bomber (B) designation was kept, but the sequence was restarted with B-1 (assigned to the Rockwell International B-1 Lancer).
The XB-1, called Super Cyclops by Huff-Daland, was a development of the Huff-Daland XHB-1. The new design had twin engines and a twin tail but was about the same size as the XHB-1. The XB-1 (S/N 27-334) was significantly underpowered with the original Packard engines so Curtiss Conqueror engines were fitted to the aircraft (and it was redesignated XB-1B). The performance of this aircraft was less than expected also, and it never entered production.
The Super Cyclops had an unusual design for its rear gunner positions. The two rear gunners were located in the aft section of the engine nacelles -- one on each wing. The reason for this was to provide a clear field of fire without obstruction from the tail assembly.
First B series bomber
TECHNICAL NOTES: Armament: Six .30-cal. machine guns and 2,500 lbs. of bombs (up to 4,000 lbs. for short distances) Engines: Two Packard 2A-1530s of 510 hp each Top speed: 100 mph at sea level Service ceiling: 15,000 ft. Range: 700 miles with full bomb load Span: 85 ft. 0 in. Length: 61 ft. 6 in. Height: 19 ft. 3 in. Weight: 16,000 lbs. gross Crew: Five Serial number: 27-334, XP-480