Boeing 377 Stratocruiser 377-10-19

The Boeing 377 began as a civil derivative of the Boeing Model 367, the C-97 Stratofreighter, which had first flown in late 1944. William Allen, Boeing's president from September 1945, was looking for a civil aircraft to replace reduced military production after the Second World War, and saw in that large, fast, long-ranged military transport the basis for a passenger aircraft suited to premium service on transoceanic routes, following the precedent of the Boeing 314 Clipper sold to Pan American. Despite the recession of late 1945, Allen ordered fifty Stratocruisers without a single airline order in hand.

On 29 November 1945 Pan American World Airways became the launch customer with the largest commercial aircraft order in history to that point: $24.5 million for twenty Stratocruisers.

The 377-10-19 was the prototype, and a single example was built. Its first flight, on 8 July 1947, came two years after that first commercial order. The flight test fleet of three 377s accumulated 402,000 km of flying to test the aircraft's limits before certification.

The prototype did not end up in a museum: it was reconditioned to 377-10-26 production standard and sold to Pan American World Airways in 1950. Of the 56 airframes built — the prototype plus 55 production aircraft — none was preserved on display in original configuration.