While fitting adequate blast deflectors and other minor changes for Phantom operation were estimated to cost no more than £5 million in 1968, refitting the ship to operate with a modern airgroup of Phantoms into the late 1970s was clearly going to cost much more, and the new Conservative government in 1970 confirmed plans to convert to a Commando carrier and withdraw "Eagle". In February 1972, the Secretary of State for Defence, Lord Carrington, estimated refitting "Eagle" to operate Phantoms would cost £25–30 million, and the overall manpower and cost requirements of operating two large strike carriers were beyond Britain, particularly as "Ark Royal" was expected to serve to the end of the 1970s with only two short refits. To preserve "Eagle" in maintained or unmaintained reserve would require refits, estimated at around £4 million, every 3–4 years, and maintenance crew of 350–400 Navy personnel for 1.5-2 million pounds a year. Reactivation would take four and a half months to a year, while maintaining a Sea Vixen squadron was unjustified expense for aircraft that were obsolete. The refit of "Ark Royal" cost £32 million to allow operations of a fully modern airwing, though it was generally accepted that even after her return to service she considered to be in a significantly worse overall material state in comparison to "Eagle". Of the 48 Phantom FG1s ordered for the FAA, 20 were diverted to the RAF equipping 43 Sqn, though some were loaned back to the Navy to equip the Phantom FG1 training unit 767 NAS which trained both RN and RAF Phantom crews until it was disbanded in 1972.