 Heathrow was therefore designated as London's airport.Croydon returned to civil control in February 1946; a diagram in the issue of "Flight" magazine dated 11 April shows ground run in the 170–350 direction, 060-240 and 120–300 ("the numbers are degrees clockwise from north").Northolt opened to the airlines soon after that, cutting Croydon's traffic, but the September 1946 ABC Guide shows 218 departures a week to Belfast, Dublin, Liverpool, Manchester, Glasgow (Renfrew), Jersey, Guernsey, and several continental airports.