Northern Ireland, all helicopters were ARMY.
Sep 1971, Wessex called out to transfer a badly injured soldier from hospital in Londonderry to Belfast. Aircraft captain was a Royal Marine and the co-pilot was RAF. At Londonderry, they shut down on the helipad and waited the call in a crew room. Amused to hear on the midnight news that an Army helicopter was waiting for the casualty to be cleared for transfer. Eventually cleared to RTB without the casualty.
Later discovered that the mis-identification Army/RAF was a deliberate ploy.