Input (grade 12): Heathrow Terminals 1, 2, 3, opened 16 December 1977 (as Heathrow Central); renamed Heathrow Central Terminals 1,2,3 on 3 September 1983; renamed 12 April 1986.
Output (grade 11): Heathrow Terminals 1,2,3, opened 16 December 1977 (as Heathrow Central); renamed Heathrow Central Terminals 1,2,3 3 September 1983; renamed 12 April 1986.