Unfortunately, the Jet Provost T.4 in general, suffered major fatigue problems throughout its RAF career. These problems, which subsequently led to the development of the Jet Provost T.5, reduced the T.4's service life considerably. During the mid-1970's many T.4's had been withdrawn from RAF service because of these problems. Some aircraft were used as ground instructional airframes at RAF stations, whereas others were placed on fire dumps, burnt and then scrapped.

The small number of surviving airworthy aircraft, all with a fair amount of fatigue life remaining, were gathered together and re-issued to RAF Shawbury to join the CATCS (Central Air Traffic Control School) fleet. XP556 was one of these airframes and, following a short period at RAF Leeming with 3FTS, was moved to Shawbury in December 1976. The aircraft was given the fleet code 'B', and remained in CATCS service until July 1989, when the School retired their aircraft and switched to a purely computerised training schedule.

Later that month, XP556 was placed in long-term store at Shawbury alongside the rest of the CATCS fleet. Two years later, the aircraft was moved to RAF Halton to be used by the RAF's 1SoTT (School of Technical Training). It was given the maintenance registration 9027M, and used as an instructional airframe for training future RAF technicians.

During 1993, the RAF announced that 1SoTT would close, and most of its aircraft disposed of. XP556 did not leave Halton for two years, and was eventually removed in mid-1995, bound for its new temporary home at Bruntingthorpe airfield. Looked after by Phoenix Aviation, XP556 was and eventually moved to its new home near RAF Cranwell on February 14th 1996.
It remains there today, on display at the RAF Cranwell Aviation Heritage Centre, and is maintained by Andy Ward and a small team of volunteers.