The Blackburn B.48 Firecrest, given the SBAC designation YA.1, was a single-engine naval strike fighter built by Blackburn Aircraft for service with the British Fleet Air Arm during the Second World War. It was a development of the troubled Firebrand, designed to Air Ministry Specification S.28/43, for an improved aircraft more suited to carrier operations. Three prototypes were ordered with the company designation of B-48 and the informal name of "Firecrest", but only two of them actually flew. The development of the aircraft was prolonged by significant design changes and slow deliveries of components, but the determination by the Ministry of Supply in 1946 that the airframe did not meet the requirements for a strike fighter doomed the aircraft. Construction of two of the prototypes was continued to gain flight-test data and the third was allocated to strength testing. The two flying aircraft were sold back to Blackburn in 1950 for disposal and the other aircraft survived until 1952. Design The Firebrand required significant effort by Blackburn to produce a useful aircraft and the first discussions on a redesign of the aircraft with a laminar-flow wing took place in September 1943. The new wing was estimated to reduce the weight of the wing by and increase the aircraft speed by . The extent of redesign increased and this led to a new fuselage and other improvements. In October 1943, Blackburn's design staff, led by G.E. Petty, started work on this development of the Firebrand which led to Specification S.28/43 being issued by the Air Ministry on 26 February 1944 covering the new aircraft. The specification was designed around a Bristol Centaurus 77 radial engine with contra-rotating propellers that allowed the size of the rudder to be reduced. 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