Four-engined bombers, such as the Avro Lancaster and Boeing B-29 Superfortress, with their range and massive carrying capacity, were natural prototypes for post-war next-generation airliners.
Četveromotorni bombarderi kao Avro Lancaster i Boeing B-29, sa svojim dugim doletom i velikim kapacitetom ukrcaja, bili su logični prototipovi putničkih zrakoplova sljedeće generacije.