Locking of flight deck door
56.—(1)  An AOC holder must ensure that, for a flight of any small aeroplane that is equipped with a flight deck door, the flight deck door is closed and locked from the time all external doors are closed following embarkation until the moment any such door is opened for disembarkation, except when the opening of the flight deck door is necessary to permit access and egress by an authorised person.
(2)  An AOC holder must establish procedures for a cabin crew member of a small aeroplane described in paragraph (1) to discreetly inform the flight crew of any security situation which may arise in the aircraft cabin.