Stearman A-21
Encyclopedia
The Stearman Model X-100 was a competitor in an United States Army Air Corps
United States Army Air Corps
The United States Army Air Corps was a forerunner of the United States Air Force. Renamed from the Air Service on 2 July 1926, it was part of the United States Army and the predecessor of the United States Army Air Forces , established in 1941...
competition for a twin-engined attack aircraft which (after redesigns) led to the Douglas A-20 Havoc, Martin A-22 Maryland and North American B-25 Mitchell.
Design and development
The X-100, designated XA-21 following purchase by the Army Air Corps, was a twin-engined high-winged monoplaneMonoplane
A monoplane is a fixed-wing aircraft with one main set of wing surfaces, in contrast to a biplane or triplane. Since the late 1930s it has been the most common form for a fixed wing aircraft.-Types of monoplane:...
of all metal construction. It featured an unusual cockpit arrangement, much like those on most German World War II bombers designed during the war years, with a streamlined greenhouse
Greenhouse
A greenhouse is a building in which plants are grown. These structures range in size from small sheds to very large buildings...
canopy enclosing both the pilot and bombardier
Bombardier (air force)
A bombardier , in the United States Army Air Forces and United States Air Force, or a bomb aimer, in the Royal Air Force and other Commonwealth air forces, was the crewman of a bomber responsible for assisting the navigator in guiding the plane to a bombing target and releasing the aircraft's bomb...
stations.
Operational history
The XA-21 was first tested with the streamlined cockpit but this configuration was found to restrict the pilot's forward vision, and the aircraft was rebuilt with a conventional (stepped) nose and cockpit structure. Although this change in the cockpit did not significantly affect performance, the XA-21 was not ordered into production.'The sole XA-21 had serial number 40-141.