The Doflug D-3803 was the final member of the Morane-Saulnier M.S.405/ M.S.406 family, and was an improved version of the D-3802 developed by Dornier in Switzerland. The Swiss had a long connection with the M.S.406 family. The D-3800 had been a licence-built aircraft that combined the fuselage and wings of the M.S.405 with the engine of the M.S.406. It was followed by the D-3801, which was developed in Switzerland after the fall of France, but that was based on the M.S.412, which had been developed by Morane-Saulnier.
Next was the Doflug D-3802. This was a development of the M.S.450, which had been designed in 1937-39 but that hadn't been ordered into production in France. The M.S.450 was visually very similar to the M.S.406, although used more modern construction methods. The D-3802 was a similar aircraft, with a monocoque fuselage and a 1,250hp licence-built Hispano-Suiza engine. The prototype of 1944 was armed with one engine mounted 20mm cannon and four wing mounted machine guns. It was followed by eleven pre-production machines which were armed with one engine mounted and two wing mounted 20mm cannon.
The D-3803 was developed while the pre-production D-3802As were being built. It was the first member of the M.S.405 family to see major changes to the fuselage. The rear fuselage was cut down and an all-round vision canopy was installed. Similar changes had been made to later versions of the Mustang, the Thunderbolt and the Spitfire.
The D-3803 was armed with the same three cannons as the D-3802A. It shared the same wings, tail and undercarriage as the D-3802, but was given a 1,430hp licence built Hispano-Suiza YS-3 engine. It made its maiden flight in May 1947, but the new engine proved troublesome. By the time these problems had been fixed the Swiss had decided to buy war surplus P-51D Mustangs and the D-3803 didn't enter production. The single example joined the twelve D-3802s in Fliegerstaffel 17 of the Swiss Air Force.
Engine: Saurer (Hispano-Suiza) YS-3 12-cylinder liquid cooled engine
Span: 32ft 10 1/2in
Length: 30ft 7 1/3in
Height: 12ft 4in
Empty weight: 6,493lb
Maximum take-off weight: 8,595lb
Max speed: 422mph at 22,965ft
Climb Rate: 3,012ft/min
Range: 404 miles
Armament: One engine mounted and two wing mounted 20mm cannon