The Vultee V-90 was designed as a heavy single-seat dive-bomber for the US Army. In 1943 the USAAF changed its role to low-level attack and then cancelled it. However, the first prototype was completed as a testbed for the 3000-hp P&W R-4360 Wasp Major engine, needed for the B-29. It first flew on 11 February 1944. Here it is seen during testing at NAS Patuxent River as the US Navy compared this aircraft to its Douglas AD Skyraider and Martin AM Mauler. Subsequently used by Pratt & Whitney as NX60373. Scrapped in 1950. Photo from: Naval History and Heritage Command