It's not an RAF aircraft, but rather owned by QinetiQ.
"It comprises the greater part of DERA, the British Government's "Defence Evaluation and Research Agency". Until July 2001, DERA was an agency of the UK Ministry of Defence, incorporating the bulk of the MoD's non-nuclear research, technology and test and evaluation establishments. It then split into two organisations, DSTL and QinetiQ Group plc. DSTL remains part of the MOD
and continues to handle the most sensitive areas of research.
As I recall, QinetiQ got a killer deal on the ex GAF Alpha Jets.