Included among exhibits at the Salon de l'Aeronautique held in Paris in November 1936 was a striking all-metal twin-engined three-seat fighter. It had a somewhat abbreviated oval-section monocoque fuselage, a shoulder-mounted semi-cantilever wing carrying split trailing-edge flaps over its entire span and two 450hp Renault 12Roi 12-cylinder inline air-cooled engines projecting ahead of the fuselage nose. This, the H.220, had been designed to a C3 requirement prepared by the Service Technique de l'Aeronautique and issued in October 1934. Other contenders were the Breguet 690, the Potez 630, the Loire-Nieuport 20 and the Romano 110. As it became evident that the H.220 would be underpowered, the Renault engines were discarded in favour of 680hp Gnome-Rhone 14M 14-cylinder radials, and, with these installed, the first flight test was made at Avord on 21 September 1937. The intended armament of the H.220 comprised two forward-firing 20mm cannon and two aft-firing 7.5mm MAC 1934 machine guns on a flexible mounting, but, in the event, no armament was fitted. On 17 February 1938, the prototype made a forced landing at Avord after losing the starboard propeller following a failure in the reduction gearbox. The poor stability evinced during flight testing of the H.220 (which had resulted in progressive changes in the contours and size of the vertical surfaces), coupled with inadequate internal capacity and some lack of sturdiness revealed by the forced landing (as a result of which the fuselage was irreparable), dictated major redesign, resulting in the H.220-2.

3-View

A three-view drawing (1703 x 1277)