The 307's design was based on the airframe of the Boeing B-17, and employed its wings, tail plane, and engines. Pan American Airways and Trans World Airlines ordered nine aircraft, each of which could carry up to 33 passengers. The modified prototype later crashed near Mt. Rainier during tests for KLM Airways on March 18, 1939.
World War II ended production of more 307s, and the existing planes were drafted for military duty. Several survived and resumed civilian service, chiefly in developing nations.
A 307 was restored to flyable condition by a group of Boeing retirees and Museum of Flight volunteers and was to be delivered to the National Air & Space Museum in 2002.
Unfortunately, on March 28, 2002, the restored Stratoliner developed engine trouble while on a test flight and ditched into Elliott Bay. No one was injured, and the damaged aircraft was retrieved, but its future became uncertain.