XH903 was the 65th of 85 Javelin FAW7s built by the Gloster Aircraft Company under contract Acft/11329/CB7(b) of 19 October 1954. It was completed in early 1959 and was delivered from the Gloster factory at Hucclecote on 27 February to RAF St Athan. After service acceptance checks with 19 MU it was assigned to 23 Squadron at RAF Coltishall and detached to RAF Horsham St Faith on 1 May.
XH903 came back to Gloster’s Moreton Valence factory on 1 June 1960 for changes to systems and equipment and replacing the Sapphire Sa7 engines with the reheated Sa7R . Now completed as a Javelin FAW9, it was delivered to St Athan on 5 January 1961 and on 14 February to 33 Squadron at RAF Middleton St George. Ten days later it went to RAF Leuchars on loan to 29 Squadron, returning to 33 Squadron on 3 March.
In October 1962, 5 Squadron, then flying the Javelin FAW5, began to convert to the FAW9 variant and took on charge most of 33 Squadron’s aircraft, including XH 903. Re-equipment was completed by 21 November and coincided with the Squadron’s move from RAF Laarbruch to RAF Geilenkirchen and assignment to 2 ATAF, XH 903 gaining the code “G” at this time.The aircraft flew with 5 Squadron until 20 September 1963 when it suffered a Cat3 accident. This resulted in its withdrawal from use until repairs were completed , the aircraft returning to 5 Sqn on 10 April 1964.