The Boeing 314 prototype was launched into the Duwamish River on 31 May 1938 and towed to Elliott Bay. It first flew on 7 June. Test pilot Eddie Allen reported that directional control was inadequate. The single tailfin was replaced by endplate fins but this was still insufficient and a central fin was put back on to make it a triple tail. NC18601 entered Pan Am service as Honolulu Clipper. On 4 November 1945 on a flight from Honolulu to San Francisco it made an emergency landing on the ocean with two engines out. Damaged, it was sunk by naval gunfire. Photo from: Boeing