Jane's All the World Aircraft 1938 / 03 - All the world's aeroplanes

The world’s largest bomber: The Boeing XB-15 which is even bigger than the B-17s already in service. At the moment it has four four 1,000 h.p. Pratt & Whitney "Twin-Wasp Senior" engines but obviously could do with engines even more powerful.

Flight 1938-05 / Flight

In the news: The Boeing XB-15 bomber, which the newspapers delight in calling “the flying fortress.” At present it has four 1,000 - 1,100 h.p. P. and W. Twin Wasps.

Flight 1937-10 / Flight

THE WORLD'S LARGEST LANDPLANE: The Boeing XB-15, which is much bigger even than the YB-17s and which is probably the largest landplane now flying, spurns back the soil on an early test take-off. Designed in the first instance for engines of 1,500 - 2,000 h.p., she is fitted at the moment with four 1,000 h.p. Twin Wasps.

Мировая Авиация 183

Еще одним самолетом, созданным в рамках программы "Project D", стал Boeing XB-15. Это был самый большой и тяжелый американский самолет на момент первого пролета в 1937 году. Построили единственный экземпляр.

Flight 1937-06 / Flight

Flight 1937-06 / Flight

The experimental XB-15 Boeing (four Twin-Wasps), which is even larger, but which, according to the latest information, has not been flown.

Air Pictorial 1956-06 / J.Blake - U.S. Bomber designations 1919-56

The 35-ton, 150-ft.-span XB-15 first flew on 15th October 1937. In 1939, as part of the Air Corps' 30th Anniversary Celebrations, it broke the weight-to-height record held by Russia. Armament was fitted in nose and dorsal turrets, and two lateral and two ventral blisters. The Pratt & Whitney SC-G motors, of 1,050 h.p. each, could be reached in flight through the wing.