XP984 was the last of 4 P.1127 Development Batch aircraft. With the Pegasus 5 engine and the revised swept-wing she effectively became an aerodynamic prototype for the Kestrel FGA.1. XP984 was damaged in a landing accident at Bedford on 31 October 1975.
XS695 was delivered to the Tripartite (Anglo-American-German) Kestrel Evaluation Squadron at RAF West Raynham on March 30, 1965 and later went to the A&AEE at Boscombe Down, where it was damaged in a landing accident on March 1, 1967.