The X-100, designated XA-21 following purchase by the Army Air Corps, was a twin-engined high-winged
monoplane of all-metal construction. 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. ==Operational history==