The LeO H-246 was designed by the French aircraft manufacturer Lioré-et-Olivier to meet a 1935 specification for a commercial flying boat for use on the Mediterranean routes of Air France [REF].
The prototype H-246.01 (Lioré et Olivier's factories had been nationalised at the end of 1936, so the aircraft was built by Sud-Est) made its maiden flight from the Étang de Berre on 30 September 1937 [REF].