The Keystone B-5A Panther was a twin-engined biplane bomber produced in 1930 by equipping the last 27 B-3A Panthers with Wright engines. The change of engine made little or no difference to the performance of the aircraft, but was made in order to share the limited number of Army contracts available between the major engine manufacturers.
While the B-3 was powered by Pratt & Whitney engines, the three Y1B-5s were produced by fitting Wright R-1750 radial engines to three of the aircraft ordered as the LB-14. The 27 production B-5As were diverted from the 63 aircraft originally ordered as B-3As, explaining why the production aircraft have lower serial numbers (30-317 to 30-343) than the service test aircraft (30-354 to 30-356).
Other than the engines the B-5 was identical to the B-3, with the same single rudder on the tail, the same distribution of the three guns and the same bomb load. The two aircraft had very similar performance figures, and by the time they entered service were on the verge of being made obsolete by a new generation of all-metal monoplane bombers. Despite this a second generation of Wright-powered Panthers was ordered in 1931, entering service in the following year as the B-6A.
Engine: Wright R-1750-3 Cyclone 9
Span: 74ft 9in
Length: 48ft 10in
Height: 17ft 2in
Empty Weight: 7,705lb
Gross Weight: 12,925lb
Maximum Speed: 111mph
Climb rate: 540 feet per minute
Range: 815 miles
Guns: Three 0.30in Browning machine guns
Bomb load: 2,496lb max, 1,995lb standard