The Latécoère 631 was a civil transatlantic flying boat built by Latécoère, the largest ever built up to its time. The type was not a success, being unreliable and uneconomic to operate. Five of the eleven aircraft built were written off in accidents and one was lost during World War II. The Latécoère 631 was the result of a specification issued in 1936 by the Direction Générale de l'Aviation Civile for a 40-passenger airliner with a range of 4,000 kilometres (2,500 mi). The aircraft was ordered in 1938. It was intended that it would be powered by six Gnome et Rhône P.18 engines of 1,650 horsepower (1,230 kW) each. A competitor for this specification was the SNCASE SE.200 Amphitrite. Construction of the aircraft was stopped due to the outbreak of World War II and was not resumed until after the signing of the Franco-German Armistice. The prototype, registered F-BAHG, first flew on 11 November 1942. It was subsequently confiscated by the Germans, and passed to the Luftwaffe, who allocated the codes 61+11. The aircraft was flown to Lake Constance, where it was destroyed in an attack by two Royal Air Force de Havilland Mosquito aircraft on 17 April 1944. SNCASE SE.200 Amphitrite 20+01 was destroyed in the same attack. For details of the history and accidents of the 631, click here.