Boeing B-52 Stratofortress B-52A

Only three B-52As, the first production version, were built, all loaned to Boeing for flight testing. Compared with the prototypes, it had a redesigned forward fuselage: the bubble canopy and tandem seating were replaced by side-by-side seating with a 21-inch nose extension for more avionics and a sixth crew member. A tail turret with four 0.50-inch machine guns and a fire-control system was added, along with a water-injection system with a 360-US-gallon tank to boost engine power; each B-52A was powered by Pratt & Whitney J57-P-1W engines rated at 44 kN dry thrust each, up to 49 kN with water injection.