19—If any aircraft flies or attempts to fly over any prohibited zone or being an aircraft in the service of a foreign State flies or attempts to fly over any part of the British Islands or the territorial waters adjacent thereto in contravention of this Act, it shall be lawful for any commissioned officer in His Majesty’s Navy, Army, or Marines [not below the rank of], to cause a gun to be fired as a signal, and if, after such gun has been fired, the aircraft fails to respond to the signal by complying with such regulations as may be made by the Secretary of State under this Act for dealing with the case, to fire at such aircraft, and any such commissioned officer and every other person acting in his aid or by his direction shall be and is hereby indemnified or discharged from any indictment, penalty or other proceeding for so doing. JURISDICTION 20—(1) For the purpose of giving jurisdiction under this Act every offence shall be deemed to have been committed in the place in or over which the same was actually committed or in any place in which the offender may be. (2) Where any person, being a British subject, is charged with having committed any offence on board any British aircraft in the air, over the high seas, or over any foreign country, or on board any foreign aircraft to which he does not belong, or not being a British subject is charged with having committed any offence on board any British aircraft in the air over the high seas, and that person is found within the jurisdiction of any Court in His Majesty’s dominions which would have had cognisance of the offence if it had been committed on board a British aircraft within the limits of its ordinary jurisdiction, that Court shall have jurisdiction to try the offence as if it had been so committed. (3) Where any offence is committed in any aircraft in the air over the British Islands or in the territorial waters adjacent thereto, the offence shall be deemed to have been committed either in the place in which the same was actually committed or in any place in which the offender may be. SUPPLEMENTARY PROVISIONS AS TO BRITISH AIRCRAFT 21—(1) If any person assumes the British national character on an aircraft owned in whole or in part by any person not qualified to own a British aircraft for the purpose of making the aircraft appear to be a British aircraft, the aircraft shall be liable to be seized and detained under this Act unless the assumption has been made for the purpose of escaping capture by an enemy or by any person in the exercise of some belligerent right.