IN 1963 three configurations were considered for the conversion to helicopter carriers: Schemes "X", "Y" and "Z". X was deck space for one helicopter and a hanger for three at the cost of the rear 6-inch turret, Y gave deck space for two Wessex helicopters and hangar for four once the 6-inch and 3-inch armament were removed, Z was same deck space and hangar capacity as Y but two helicopters could take off (or land) at once. Z was chosen as the best option even for a projected six-year lifespan and expected to take 15 months and £2 million per ship. The final cost was £12 million in dockyard costs for all three including refits at the same time and £10.5 million for the helicopters. It was recognised that 75 pilots would also be needed at a time when the FAA was 37 pilots short.