North American B-45 Tornado. Interior of Building 4401 (or possibly 4402) at Muroc Army Airfield, California, USA, looking east at hangar doors with a North American Aviation XB-45 Tornado jet aircraft in the foreground. This airbase was later renamed Edwards Air Force Base, and was the site for much of the early testing of military aircraft. The North American B-45 Tornado was the US Air Force's first operational jet bomber. It first flew in March 1947, with the three prototypes designated XB-45. It had a crew of four and was 23 metres long. In the background are the sliding doors needed to accommodate large aircraft. Photographed in 1947.