No person shall be in any part of an aircraft in flight which is not a part designed for the accommodation of persons, unless temporary permission has been granted by the PIC to access such part of the aircraft—
(a) for the purpose of taking action necessary for the safety of such aircraft or of any person, animal or goods therein; and
(b) in which cargo or stores are carried, being a part which is designed to enable a person to have access thereto while such aircraft is in flight.