NB-1

The Boeing NB‑1 was a pioneering experimental transport aircraft developed in the early 1930s as part of the United States Army Air Corps’ “New Bomber” program, which sought a versatile platform that could combine cargo, passenger, and reconnaissance roles. First flown on 12 April 1932, the NB‑1 incorporated a low‑wing monoplane layout of all‑metal construction, a radical departure from the fabric‑covered biplanes that dominated the era. Powered by two 750‑horse‑power Pratt & Whitney R‑1830 radial engines mounted on nacelles beneath the wings, it delivered a maximum speed of 210 mph and a range of 1,500 km, enabling long‑distance supply runs across remote territories.

Key features included a spacious, modular fuselage with removable bulkheads, allowing quick reconfiguration between troop transport, medical evacuation, and freight carriage. The aircraft also pioneered retractable landing gear and a fully enclosed cockpit with heated instrumentation, improving crew comfort and operational capability in harsh climates. Though only three prototypes were built before the program was cancelled in favor of larger, more powerful designs, the NB‑1’s innovative structural concepts and multi‑mission flexibility heavily influenced later Boeing work such as the Model 247 and the famed C‑97 Stratofreighter. Its legacy endures as an early example of a truly versatile airframe, shaping the evolution of military and commercial transport aviation.