On all commercial aircraft which transport passengers for compensation or hire the door which separates the pilot compartment from the passenger compartment shall be kept locked at all times the aircraft is in a flight over this state during which passengers are being transported except:
The pilot of the aircraft shall be guilty of a misdemeanor if the door is not so locked.
It shall be unlawful for any person, except a member of the crew, to have in his possession in the passenger compartment at any time the aircraft is in a flight over this state during which passengers are being transported a key or other device for opening such door from the passenger side of the door.
Ca. Pub. Util. Code § 21416