The Douglas XB-31 (Douglas Model 332) was the design submitted by Douglas after the request by the United States Army Air Forces for a very heavy bomber aircraft, the same request that led to the Boeing B-29 Superfortress, Lockheed XB-30, and Consolidated B-32 Dominator.

Douglas XB-31(Douglas Model 332是道格拉斯飞行器公司为美国陆军航空军提出的超重型轰炸机设计，同时的竞争对手还有B-29超级堡垒轰炸机、XB-30轰炸机和B-32统治者轰炸机。

Douglas XB-31(Douglas Model 332是道格拉斯飛行器公司為美國陸軍航空軍提出的超重型轟炸機設計，同時的競爭對手還有B-29超級堡壘轟炸機、XB-30轟炸機和B-32統治者轟炸機。

Douglas XB-31(Douglas Model 332是道格拉斯飛行器公司為美國陸軍航空軍提出的超重型轟炸機設計，同時的競爭對手還有B-29超級堡壘轟炸機、XB-30轟炸機和B-32統治者轟炸機。

2017年2月10日 · The Douglas XB-31 "Raidmaster" became one of four submissions passed along to the United States Army Air Forces (USAAF) during World War 2 (1939-1945) attempting to fulfill a requirement for a new long-range, high-altitude "super heavy bomber".

The Douglas XB-31 (company designation of Model 332) was somewhat larger and heavier than the other three competitors. It had a high-mounted wing, and was to have been powered by four Wright R-3350 air-cooled radials driving three-bladed propellers.

The Douglas XB-31 was the designation given to a series of Douglas designs produced as part of the same design contest that produced the Boeing B-29 Superfortress, none of which were ever built.

The Douglas XB-31 (Douglas Model 332) was the design submitted by Douglas after the request by the United States Army Air Forces for a very heavy bomber aircraft, the same request that led to the Boeing B-29 Superfortress, Lockheed XB-30, and Consolidated B-32 Dominator.