After the partial destruction of the H.220, major redesign was initiated by the Societe Nationale de Constructions Aeronautiques du Centre, or SNCA du Centre, which had absorbed the Hanriot facility at Bourges on 1 February 1937. The oval-section monocoque fuselage of the original H.220 was discarded in favour of a fuselage built as two half shells mated by a central keel. An entirely new tail assembly with twin endplate vertical surfaces was fitted and the Gnome-Rhone 14M radial engines were enclosed by low-drag nacelles. These features were mated with the wing of the original H.220 to result in the H.220-2, which was first flown (as the H.220 No 02) on 17 March 1939. Four months later, in July 1939, this prototype was to be displayed statically as the NC 600 No 01 multi-seat fighter at the Salon de l'Aeronautique. In fact, the genuine NC 600 was to differ from the H.220-2 in several major respects.