21.—(1) Subject to paragraph (2), an aircraft must not fly below flight level 100 at a speed which, according to its air speed indicator, is more than 250 knots.
(2) Paragraph (1) does not apply to—
(a)flights in Class A airspace;
(b)VFR flights or IFR flights in Class B airspace;
(c)IFR flights in Class C airspace;
(d)VFR flights in Class C airspace or VFR flights or IFR flights in Class D airspace when authorised by the appropriate air traffic control unit;
(e)an aircraft taking part in a flying display for which a permission is required by article 69(1) of this Order, if the flight is made in accordance with the terms of the permission granted to the organiser of the flying display and in accordance with the conditions of the display authorisation granted to the pilot under article 69(8) of this Order;
(f)an aircraft flying in accordance with a written permission granted by the Governor authorising the aircraft to exceed the speed limit in paragraph (1).
(3) The Governor may grant a permission for the purpose of paragraph (2)(f) either generally or in respect of any aircraft or class of aircraft.