27. Exemption from control: crews of ships, aircraft and trains.

Where a member of the crew1 of a ship2, aircraft3, through train4 or shuttle train5 arrives at a place in the United Kingdom6 under an engagement requiring him to leave on that ship as a member of the crew, or to leave within seven days on that or another aircraft, through train or shuttle train as a member of its crew (or the crew of another such train), he may enter the United Kingdom at that place without leave and remain until the departure of the ship, aircraft or train on which he is required by his engagement to