You may also be interested in the use of XS230 with the Empire Test Pilots' School at Boscombe Down. This was the first prototype of the Mk 5, and was actually a converted Mk 4. (Some people used to call it a Mk 4½). This was used at ETPS for various things like introducing FTEs to the fast jet environment, test techniques demonstrations and for spinning teaching. I have very fond memories of this aircraft, as it was my first fast jet experience. I believe it went out of service in 1993, I presume at about the same time as the other remnants left in the RAF. I saw it an airshow the other week, and was very pleased that it is still flying (and in pretty much it's original colour).