 The Blackburn B @-@ 48 Firecrest , given the <unk> designation <unk> , was a single @-@ engine naval strike fighter built by Blackburn Aircraft for service with the British Fleet Air Arm during World War II . 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 . 
