The Morane-Saulnier M.S.406H/ D-3800 was a version of the M.S.406 single seat fighter that was built under licence in Switzerland. After seeing the M.S.405 the Swiss decided to produce the type under licence. Two aircraft were ordered as patterns for the licence construction. The first of these aircraft flew from Villacoublay to Switzerland on 11 September 1938, and was followed by the second on 15 May 1939. These aircraft, with the designation M.S.406H, actually used the fuselage and wing of the M.S.405 combined with the 860hp Hispano-Suiza 12Y31 12 cylinder inline engine used on the M.S.406 and Swiss instruments, radios and guns. These first two aircraft were given the Swiss registration numbers J-1 and J-2.
A total of 82 D-3800s were built by the Eidgennössisches Flugzeugwerk (EFW) at Emmen Switzerland. These were made up of eight pre-production aircraft and 74 series production aircraft. Another two aircraft were later built from spare parts. The original aircraft received the registration numbers J-3 to J-84. The Swiss then moved on to the M.S.412/ D-3801, which used a more powerful engine and was produced in larger numbers. Finally they introduced an improved version of the M.S.450, producing a handful of these aircraft as the Doflug D-3802.
The D-3800 differed visually from the M.S.406 in having an antenna ahead of the windshield, a tail wheel instead of a skid and in having no machine gun bulges in the wings (the drum fed guns of the French original having been replaced by belt fed guns). The D-3800 was used by three flight companies (Fliegerkompagnien) of the Swiss air force, reaching the front line by April 1940. They were later used as advanced trainers, and remained in use until 1954.
Engine: Hispano-Suiza 12Y31 12 cylinder inline engine
Span: 34ft 9 5/8in
Length: 26ft 9 1/3in
Height: 8ft 10 3/4in
Empty weight: 3,968lb
Maximum take-off weight: 5,467lb
Max speed: 295mph
Armament: One engine mounted 20mm cannon and two wing mounted machine guns