Every person subject to this Act who, being the pilot of one of Her Majesty's aircraft, flies it at a height less than such height as may be provided by any regulations issued under the authority of the Admiralty, the Army Council or the Air Council, except—
(a)while taking off or alighting ; or
(b)in such other circumstances as may be so provided,
shall be liable to imprisonment for a term not exceeding two years or any less punishment authorised by this Act.