Registered to BOAC in 1951 and converted to a Comet 2E in 1957 for use as a trials aircraft and engine testbed for development of the Comet 4. Transferred to the Ministry of Aviation in October 1960 and used by Smiths Industries to test early flight control systems, including that later used by the Trident 1E. Operated with the BLEU at Bedford as XV144 from November 1966 and later moved to Farnborough where it was used as a ground trainer and spares source for XN453 until scrapped in 1974.