Section 66 of the Airports Act 1986 empowers the Secretary of State by order to direct that, in their application to land within a designated airport, certain provisions of the Refuse Disposal (Amenity) Act 1978 and regulations in force made under those provisions are to have effect subject to modifications as appear to the Secretary of State to be necessary or expedient to confer on the airport operator the functions exercisable under those provisions by local authorities.