49 CFR 1544.225 - Security of aircraft and facilities.
Each aircraft operator must use the procedures included, and the facilities and equipment described, in its security program to perform the following control functions with respect to each aircraft operation:
(b) Prevent unauthorized access to each aircraft.
(c) Conduct a security inspection of each aircraft before placing it into passenger operations if access has not been controlled in accordance with the aircraft operator security program and as otherwise required in the security program.
(d) When operating under a full program or a full all-cargo program, prevent unauthorized access to the operational area of the aircraft while loading or unloading cargo.