239.—(1) If the Secretary of State decides it is necessary in the public interest to restrict or prohibit flying by reason of—
(a)the intended gathering or movement of a large number of persons;
(b)the intended holding of an aircraft race or contest or of a flying display; or
(c)national defence or any other reason affecting the public interest,
the Secretary of State may make regulations prohibiting, restricting or imposing conditions on flights by aircraft specified in paragraph (2) flying in the circumstances specified in paragraph (2).
(2) The aircraft and circumstances are—
(a)aircraft, whether or not they are registered in the United Kingdom, in any airspace over the United Kingdom or in the neighbourhood of an offshore installation; and
(b)aircraft which are registered in the United Kingdom, in any other airspace, being airspace for which the United Kingdom has, under international arrangements, undertaken to provide navigation services for aircraft.
(3) Regulations made under this article may apply either generally or in relation to any class of aircraft.
(4) It is an offence to contravene, permit the contravention of or fail to comply with any regulations made under this article.
(5) If the pilot in command of an aircraft becomes aware that the aircraft is flying in contravention of any regulations which have been made for any reason referred to in paragraph (1)(c) the pilot in command must, unless otherwise instructed under paragraph (6), cause the aircraft to leave the area to which the regulations relate by flying to the least possible extent over such area and the aircraft must not begin to descend while over such an area.
(6) The pilot in command of an aircraft flying either within an area for which regulations have been made for any reason referred to in paragraph (1)(c) or within airspace notified as a Danger Area must immediately comply with instructions given by radio by the appropriate air traffic control unit or by, or on behalf of, the person responsible for safety within the relevant airspace.