First flown in August 1962, XP503 spent its active career with 4 FTS before returning to Hawker Siddeley for trials at Bitteswell in 1969. Retired to instructional use at Halton as 8568M by 1977, it was acquired by Phoenix Aviation at Bruntingthorpe in the mid-1990s before sale to an owner in Palo Alto, CA in 2000 and registration as N503KC