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Posted 6/25/2009 Printable Fact Sheet
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Keystone B-3A
Keystone B-3A (S/N 30-281), the first B-3A built. (U.S. Air Force photo)
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The Keystone B-3A was originally ordered as the LB-10A, but the U.S. Army dropped the Light Bomber (LB) designation in 1930 and renamed the LB-10A, LB-13 and LB-14 aircraft on order -- B-3A, Y1B-4 and Y1B-5A.

The B-3A, along with the very similar B-4, -5 and -6 series aircraft, were the last biplane bombers used by the U.S. Army. The B-3A was a conservative design and its performance was about the same as some bombers built 10 years earlier. A bomber design revolution that would make the Keystone aircraft completely obsolete was only a few years away. The all-metal monoplane bombers of the mid-1930s were so advanced, the newest bombers were actually faster than the pursuit planes in service with the Army.

The B-3A would remain in service until 1940. The 2nd Observation Squadron at Nichols Field, Philippines, was the last unit equipped with the B-3A.

Type Number built/
B-3A 63 Redesignated LB-10A

Armament: Three Browning .30-cal. machine guns and 2,500 lbs. of bombs
Engines: Two Pratt & Whitney R-1690-3 of 525 hp each
Top speed: 114 mph at sea level
Cruising speed: 98 mph
Service ceiling: 12,700 ft.
Range: 860 miles with full normal bomb load of 2,500 lbs.
Span: 74 ft. 8 in.
Length: 48 ft. 10 in.
Height: 15 ft. 9 in.
Weight: 12,952 lbs. gross
Crew: Five
Serial number: 30-281 to 30-343

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