Stearman XA-21 with streamlined cockpit
Role Ground attack
National origin United States
Manufacturer Stearman Aircraft
First flight 1938
Status Prototype
Primary user United States Army Air Corps
Number built 1

The Stearman XA-21 (Model X-100) was a competitor in a United States Army Air Corps 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 monoplane of all-metal construction.[1] Its initial design featured an unusual "stepless cockpit" arrangement, much like those on most German World War II bombers designed during the war years from the He 111P onwards, with a streamlined, well-framed greenhouse canopy enclosing both the pilot and bombardier stations.[2]

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.[3] Although this change in the cockpit did not significantly affect performance, the XA-21 was not ordered into production.'[4]

The sole XA-21 had serial number 40-191.[5]


 United States

Specifications (XA-21)

In flight
Front view

Data from Museum of the United States Air Force[4]

General characteristics



See also

Related lists



  1. ^ "Stearman XA-21 (Stepped Cockpit)." Museum of the United States Air Force. Retrieved: 17 July 2017.
  2. ^ Bowers 1989, p. 273.
  3. ^ "Swift Attack Bombers Race For Jobs In Army Air Corps." Popular Mechanics, June 1939.
  4. ^ a b "Stearman XA-21 (Streamlined Cockpit)." Museum of the United States Air Force. Retrieved: 17 July 2017.
  5. ^ Phillips, Edward (2006). Stearman Aircraft: A Detailed History. North Branch, MN: specialtypress. pp. 135–138, 202. ISBN 9781580070874.


  • Bowers, Peter M. Boeing Aircraft since 1916. London: Putnam, Second edition, 1989. ISBN 0-85177-804-6.
  • Wagner, Ray. American Combat Planes of the 20th Century, Third Enlarged Edition. New York: Doubleday, 1982. ISBN 978-0-930083-17-5.