The Amiot 351 was one of only two members of the Amiot 350 family of twin-engined bombers to actually enter service with the French Armée d l'Air before the Battle of France.
Amiot 351 No.1 was the designation given to the Amiot 340 prototype after a number of changes were made. After official trials that began on 21 March 1938 the Aeronautical Technical Service recommended that a fourth crewman be added and that contoured engine cowlings should be added to reduce the drag caused by the radial engines. The Amiot 340 was used unmodified on a propaganda trip to Berlin in August 1938, and only then were the modifications made. At the same time the original engines 920hp engines were replaced with two 1,020hp Gnôme & Rhône 14N20/21 engines and the single vertical tail was replaced with a twin fin tail assembly. The modified aircraft, now redesignated as the Amiot 351 No.01, made its maiden flight on 21 January 1939.
Although at this point the prototype had always flown with radial engines, the first production order, placed in 1938, was for 40 aircraft powered by inline engines. The first production order for the Amiot 351, powered by 950hp Gnôme & Rhône 14N38/39 engines, was placed three weeks later, when the first order was modified to one for 40 Amiot 350s and 100 Amiot 351 B4s (four seat bombers). Problems with the 14N engines meant that this order was soon altered to one for 45 350s and 75 351s, and early in 1939 the order was modified again, to 60 351s and 60 Rolls Royce powered Amiot 353s. Another 30 Amiot 351s were ordered in a second contract, also placed at the start of 1939, before on 1 December 1939 the entire order was reorganised, this time including 140 Amiot 351s, along with forty Amiot 354s, with a more powerful version of the same engine.
Production of the Amiot 350 family was disappointing slow. Only five aircraft had been accepted by January 1940, rising to 17 by 1 March, 21 by 1 April and 37 on 1 May, by which time several hundred aircraft should have been ready.
See the Amiot 354 for the short combat record of this aircraft.