Built as part of contract 15527, and delivered to the Royal Air Force Transport Command at RAF Lyneham on 17 September 1960, serialled XM496 and named 'Regulus'. She was taken on RAFTC charge from 19 September 1960 and used within the Britannia pool from her acceptance. XM496 was withdrawn from RAF use on 27 October 1975 and stored at RAF Kemble with 18 413.45 hours and 8122 landings to her credit.

XM496 was purchased by Monarch Airline's Airline Engineering on 6 January 1976. Converted at Luton by Airline Engineering to 253F configuration and registered G-BDUP on 31 March 1976, and two weeks later she was painted in the livery of Afrek Ltd, who purchased her on 21 May 1976 and was delivered to them in Athens on 6 June 1976 with a private C of A. Later withdrawn from use and stored in Athens, Greece.

Purchased by Monarch Aircraft Engineering Ltd on 30 July 1984 and ferried to Luton for overhaul, then sold to the Cuban Airline, AeroCaribbean, in August 1984. She was painted in their full livery, and registered CU-T120. CU-T120 operated her last flight on 21 March 1990 (thereby ending all Cuban Britannia operations). While flying between Peru and Havana, No. 4 engine was shut down, an emergency declared, and a landing at Guayaquil, Ecuador made. The following day a three-engined ferry was organised and on arrival at Havana, Cuba she was grounded due to lack of spares.

This aircraft was to become the 'Phoenix' of the Britannia fleet as she was to become the last airworthy Britannia. Following sale to Transair Cargo the aircraft was flown via the UK as 9Q-CJH ‘Jack’ and operated with trans Service Airlift ltd. Reregistered as EL-WXA to Transair Cargo in August 1997. Flown to the ex RAF airfield of Kemble and placed into the care of dedicated Bristol Britannia enthusiasts, the aircraft has since been repainted in RAF Transport Command livery and is being fully preserved as a non flying example.