Slightly off thread but do they still use inches over the other side of the pond? I seem to remember that when the RAF bought the Phantom they spent about a trillion pounds fitting them with Rolls Royce engines and various other mods but balked at twopence halfpenny per aircraft to alter the altimeter scales to millibars, requiring every ATC for years to come to pass altimeter settings to Phantoms in inches. Great fun in tankers (using millibars) with a pair of them in tow.