In 1936, the French Air Ministry issued a specification calling for a large transatlantic flying boat possessing a range of 6 000 km against a 60 km/h headwind cruising at 250 km/h with a crew of six and 20 passengers plus 500 kg of freight, and weighing between 30000 kg and 40000 kg. Two design studies were prepared to meet thisrequirement, the Potez-CAMS 161 and the Lioré-et-Olivier H-49 Amphitrite. During the following year, it was concluded that the specification was too modest and the all up weight limit was raised to 70 000 kg, the desired passenger capacity was increased to 40 persons with a crew of eight and a cruising speed of 300 km/h against a 50 km/h headwind was requested. To meet the requirements of this second specification, the H-49 Amphitrite, which had originally been en-visaged as having an all up weight of 42 000 kg , was extensively revised, weight being raised to 66 000 kg , and four prototypes were ordered in 1938 under the designation SE 200 (Lioré-et-Olivier having meanwhile been incorporated in the Société Nationale de Constructions Aéronautiques de Sud-Est). The first example, SE 200 No 01 (F-BAHE), had reached an advanced stage of construction at Marignane by the beginning of WW II , and work on all four prototypes continued after the Armistice. The SE 200 No 01 was flown for the first time in August 1943 powered by six 1,500 hp Wright R-2600 Cyclone 14 engines, subsequently being ferried to Lake Constance with Luftwaffe insignia (and the identification2D+ UT). This aircraft was destroyed, in company with the Potez-CAMS 161 and the Laté 631 No 01, as a result of an RAF attack on the flying boat moorings on Lake Constance. The SE 200 No 02 was destroyed before flight testing during an RAF raid on Marignane, the third and fourth prototypes, which were in earlier stages of assembly, being damaged in the same attack. The components of SE 200 No 03 (F-BAIY) were later salvaged and the flying boat was flown for the first time on 2 April 1946. Although plans existed to complete SE 200 No 04 these never saw fruition. This fourth example was to have been fitted with semi-retractable balloon-type stabilizing floats. The SE 200 No 03 was powered by six l,600hp Gnôme-Rhône 14R26/27 14-cylinder two-row radials and had a normal fuel capacity of 36 000 l in interspar tanks. Performance included maximum speeds of 354 km/h at sea level and 378 km/h at 2 500 m), a continuous cruise of 305 km/h and a maximum range of 6 060 km. Designed empty weight was 32 746 kg, maximum loaded weight being 72 000 kg, and overall dimensions were: span 52,20 m, length, 40,15 m, wing area 340 m2.