 These would be powered by UK engines; the Bristol Olympus 7R – thrust dry, with reheat, the Rolls-Royce Conway Stage 4 – thrust dry, with reheat, or de Havilland Gyron – thrust dry, with reheat.Procurement of the Arrow from Canada, and setting up a production line in the UK, was studied, the unit price per aircraft built in the UK being estimated at £220,000 each for a production run of 100 aircraft, as opposed to the estimate of £150,000 per aircraft for the thin wing Javelin.The CF-105 would serve as a stopgap until the UK's F.155 project came to fruition, but with the F.155 due in 1963 and the Arrow not likely to reach the RAF before 1962, there was little point in proceeding.