49 CFR § 1540.111No guns in carry-on bags, even if a passenger has a concealed weapon permit. No loaded guns in checked bags. No unloaded guns in checked bags unless the passenger declares to the aircraft operator before checking the baggage, that the passenger has a firearm in his or her bag and that it is unloaded; is in a hard-sided container; and the container in which it is carried is locked, and only the passenger retains the key or combination.