4.—(1) A person may, without holding a firearm certificate, have in his possession on board a ship a firearm as part of the equipment of the ship.
(2) A person may, without holding a firearm certificate—
(a)have in his possession on board an aircraft or at an aerodrome a signalling apparatus as part of the equipment of the aircraft or aerodrome;
(b)remove a signalling apparatus which is part of the equipment of an aircraft—
(i)from one aircraft to another at an aerodrome; or
(ii)from or to an aircraft at an aerodrome to or from a place appointed for its storage in safe custody at that aerodrome,
and keep any such apparatus at such a place.
(3) If he has obtained a permit from the Chief Constable, a person may, without holding a firearm certificate, remove—
(a)a firearm from or to a ship; or
(b)a signalling apparatus from or to an aircraft or aerodrome,
to or from a place and for a purpose specified in the permit.
(4) In this paragraph “firearm” and “signalling apparatus” include ammunition for a firearm or a signalling apparatus, as the case may be.