(1) It is lawful for a police officer or the person in command of an aircraft, where he considers it necessary so to do in order to prevent the commission of a crime under Chapter XXXIA or to avoid danger to the safety of the aircraft or of persons on board the aircraft (a) to place or keep a person who is on board the aircraft under restraint or in custody; and(b) if the aircraft is not in motion, to remove a person from the aircraft.(2) It is lawful for any person to assist a police officer or the person in command of an aircraft in the exercise of the powers conferred by subsection (1) .