P.1154 V/STOL aircraft project. The projected superior fuel efficiency using the Spey engines was overshadowed by larger engine size and inflexibility. From the smaller Hermes maximum weight at takeoff would be 25 tons rather than 28 tons when operating off Eagle. Since this lower weight at launch from Hermes would be achieved by carrying less fuel, combat air patrol duration would be 25 to 50 percent less than from Eagle; from 2-2.5 hours to 1-1.5 hrs, and only partly compensated by refuelling when airborne. It was optimistically believed Hermes could replace its Vixens with Spey-powered Phantoms on a one-to-one basis, i.e. 11–12 with 7–8 Blackburn Buccaneer strike aircraft. While the Phantoms built for the RN were modified in ways similar to Vought F-8 Crusaders for the French Navy – improving deceleration on landing – the modifications were not entirely successful. Hermess flight deck was too short, her arresting gear as well as her catapults were not powerful enough to recover or launch the F-4Ks, even though they were slightly lighter, more economical and higher performing than their US Navy counterparts. The Phantom trials held on Hermes in 1969–1970 proved this, though in the views of the then Minister of Defence, Denis Healey, the carrier could operate the most modern aircraft, but in too small numbers to be effective. While it is clear that McNamara's claims that the F-4 was not safe for use on the USN , or 31,000-ton carriers, was rightly rejected by John Hay in 1964. It is clear that Hermes was not a viable substitute for CVA02, but the programme was politically and financially impossible. Proposed transfer to Australia A 1966 review indicated that Hermes was surplus to operational requirements and she was offered to the Royal Australian Navy (RAN) as a replacement for HMAS Melbourne. In 1968, Hermes took part in a combined exercise with the RAN, during which the carrier was visited by senior RAN officers and Australian government officials, while RAN Douglas A-4G Skyhawks and Grumman S-2 Trackers practised landings on the larger carrier. The offer was turned down due to operating and manpower costs. Proposed international fleet Hermes served as one of four Royal Navy strike carriers mainly in the Indian Ocean and finally in the Mediterranean Sea until decommissioned in 1970. She could have seen action against the Egyptians when Egypt closed off the Straits of Tiran to Israeli shipping in May