For civil operations, the Trident was cleared for CAT III in 1972, the VC10 in 1973. The Victor and the Vulcan beat them both however. They were fitted with autoland on the principle that if you had an aircraft airborne with a nuclear weapon on board, you really did want to have it land safely if the weather went out of limits. It used a slightly different system where at 200', the autpilot was switched from LOC to L CABLE which was a more sensitive linear aerial which was buried in the runway and extended out to the middle marker. Only about three airfields had the L CABLE system installed (I think). Anybody out there know more about this system. All I really can confirm is tha Victors still had the switchery and the Rad Alt housing in the late 80's.