http://www.legislation.gov.uk/id/uksi/2015/596

SCHEDULE 2Permitted development rights

PART 19Development by the Crown or for national security purposes

Class G – development on operational land outside an airbase

Permitted development

G.

The carrying out on operational land outside but within 8 kilometres of the perimeter of an airbase, by or on behalf of the Crown, of development in connection with the provision of air traffic services.