Roots in the NA-40

摘要

The NA-40 was a very clean aircraft which was designed in response to an attack bomber competition initiated in 1938. It had a very narrow fuselage to keep drag to a minimum housing the two pilots in a tandem cockpit enclosed under a "greenhouse" canopy. The pilot's forward cockpit was more like a fighter's than a bomber, while the bombardierwas accommodated in a fully glazed nose. The NA-40 was originally powered by a pair of 1,100 h.p. Pratt & Whitney Double Wasp engines. At first, these drove a pair of Curtiss electric propellers, although before the aircraft's maiden flight these were to be replaced by a pair of Hamilton Standard Hydromatic propellers. On January 29,1939, the NA-40, registered with the civilian serial X14221,was first flown by Paul Balfour and Frank Lyons. In its original configuration, the NA-40 proved to be a difficult aircraft to handle, aggravated by engine problems and tail buffet. The aircraft would only spend five hours in the air before being returned to the factory for modifications. The situation greatly improved when the aircraft re-emerged with a pair of 1,600 h.p. Pratt & Whitney R-2600 engines and was redesignated as the NA-40B.