History of TG500. Initially retained by HP for trials before being transferred to the A&AEE at Boscombe Down where it remained for the rest of its operational life. It was used for the development of the Universal Freight Beam a frame externally attached to the fuselage belly onto which various loads and equipment could be attached, included jeeps, field Guns and other equipment. Boscombe Down used it for general transport duties in support of trials and research projects taking it all over the world. It was updated to C1a standard with the addition of under wing fuel tanks and at about the same time gained a thimble shaped nose radome for the Ecko weather radar system (TG502 also so modified). 

By 1971 TG500 was getting to look very tired so just shortly before the Queens Royal Review of the A&AEE on 18th March 1971 it was completely repainted in a red, white and grey livery. Only 18 months later it was retired from service and flown to 71 MU at RAF Bicester for use as a training aid for salvage crews. By the 13th of April 1973 the four propellers had been removed then by 1975 it had been dismantled and moved to the dump where it was scrapped soon after, although some reports say the major components went to the RAF Catterick fire school during 1976.