Between 1932 and 1936,
Nieuport-Delage had been developing a two-seat dive bomber, the Nieuport Ni.140, for the
Aéronautique Navale, the aviation arm of the
French Navy. It was renamed
Loire-Nieuport LN.140 after the
Nieuport company was absorbed into
Loire-Nieuport, in 1933. The first of two prototypes, the LN.140-01, was flown on 12 March 1935, but had crashed in July during a forced landing, not being repaired. Flight testing continued with the second prototype, the LN.140-02, until development was abandoned after, that too, crashed in July 1936. Development efforts were then concentrated on the LN.40 project which benefited from experience with the LN.140, but was a new, and aerodynamically more refined design, replacing the fixed and spatted undercarriage of the LN.140 with rearward retracting main gear legs, and dispensing with the second crewman. In the second half of 1937 an order was received for a prototype, followed by orders for seven production aircraft for the
aircraft carrier Béarn and three more for operational evaluation by the air force. The
French Air Force had expressed interest in a land-based derivative of the LN.40, designated the
LN.41. Initial plans were for 184 to equip six dive bomber squadrons with 18 aircraft each, plus reserves. The prototype made its first flight on 6 July 1938, the second followed in January 1939, and the third in May. Four of the pre-series LN.40 dive bombers were delivered in July, and it passed its carrier trials aboard the
aircraft carrier Béarn. Nevertheless, the flight tests found that the dive brakes were ineffective, which led to their being removed in favour of using the extended landing gear doors as air brakes. The LN.40 also could not carry out diving attacks with full fuel tanks. The aircraft was too slow for the air force which requested the development of a faster dive bomber, which would become the
Loire-Nieuport LN.42. In July 1939, Loire-Nieuport had received orders for 36 LN.401 production dive bombers for the Navy, and 36 LN.411 aircraft for the Army. The LN.411 was almost identical to the LN.401, except for the deletion of the arrestor hook, the wing folding mechanism and the emergency floatation devices. The first LN.411s were delivered in September which coincided with an order from the air force for 270 more but in October they were refused, and the LN.411s were sent to the Navy. Loire-Nieuport also attempted to develop a faster version, by substituting an
Hispano-Suiza 12Y-31 for the
Hispano-Suiza 12Xcrs engine of the LN.401. This
LN.402 made its first flight on 18 November 1939. Further development of the LN.402 was prevented by the
French defeat in May 1940 and
the following armistice. The final development was the LN.42 dispensed with the inverted gull wing and elevator endplates and used the much more powerful
Hispano-Suiza 12Y-51 engine but was too late for the
Second World War, making only a few short hops before France fell during the 1940
invasion of France when it was hidden from the Germans for the duration of the war. Flight trials resumed on 24 August 1945 and ran until 1947, however no interest was forthcoming of the now obsolete type and only one example was built. ==Operational history==