The new design, given the company designation "B.48", was known unofficially by Blackburn as the "Firecrest" but was always known by S.28/43, the Air Ministry specification. It was a low-winged, single-seat, all-metal monoplane. Aft of the cockpit the fuselage was an oval-shaped stressed-skin semi-monocoque, but forward it had a circular-section, tubular-steel frame. The cockpit of the Firecrest was moved forward and raised the pilot's position so that he now looked over the wing leading edge, and down the nose. The canopy was adapted from the Hawker Tempest fighter. In the rear fuselage was a single fuel tank with two fuel tanks in the centre wing section. The aircraft had a redesigned, thinner, inverted gull wing of laminar flow aerofoil section. The wing consisted of a two-spar centre section with just over 6.5° of anhedral and outer panels with 9° of dihedral. It could be hydraulically folded in two places to allow more compact storage in the hangar decks of aircraft carriers. Four Fowler flaps were fitted to give good low-speed handling for landing and the wing had retractable dive brakes on both surfaces. In the course of the redesign the structure was simplified which reduced weight by and even after the fuel capacity was increased by the gross weight was still less than that of the Firebrand.