In 1930, three Keystone bombers were ordered under the designation LB-14. They were to be equipped with single vertical tails and were to be powered by a pair of 525 hp Pratt & Whitney GR-1860 radials.
In 1930, the USAAC abandoned its separate designation categories for light (LB) and heavy (HB) bombers, and classified them both under the B category. The LB-14s that were ordered were to be completed as Y1B-5s with 525 hp Wright R-1750-3 engines. Serials were 30-354/356. However, it is uncertain if these were ever actually delivered. In any case, these serials conflicted with those assigned to the Douglas O-25A.
Specification of the Keystone Y1B-5:
Two 525 hp Wright R-1750-3 air-cooled radial engines. Maximum speed 111 mph at sea level Weight: 13,100 pounds gross. Wingspan 74 feet 9 inches, length 48 feet 10 inches, height 15 feet 9 inches, wing area 1145 square feet. Two Lewis machine guns in an open gunner's position in the nose, two Lewis machine guns in an open dorsal gunner's position, one Lewis gun firing downward through an opening in the lower fuselage.