I have searched for over an hour and can't find the Ordinances for Raleigh Durham Airport. I did find their Chapter 13 which covers Transportation at the airport but I believe they don't have the ordinances online. Other posters have stated that RD Airport is owned by the counties or cities around it. If so it would be city or county government property. The Preemption law covering firearms is below along with a link to the NC Statutes.
If RD Airport is owned by the local government they can ban firearms from all the property including the parking lots. But the preemption law specifically states they can not ban the storage of firearms in a vehicle parked on their property. Does that mean I can have it loaded while entering the airport parking lot then store it once I am parked? I would think not. It would have to be stored before entering their property.
It has been stated they have signs posted before entering the airport property saying no firearms, then carrying a firearm loaded would most likely be a violation of their ordinances. If they have signs they most likely have an ordinance.
§ 14-409.40. Statewide uniformity of local regulation. (General Law)
North Carolina General Assembly - General Statutes Table of Contents
(f) Nothing contained in this section prohibits municipalities or counties from application of their authority under G.S. 153A-129, 160A-189, 14-269, 14-269.2, 14-269.3, 14-269.4, 14-277.2, 14-415.11, 14-415.23, including prohibiting the possession of firearms in public-owned buildings, on the grounds or parking areas of those buildings, or in public parks or recreation areas, except nothing in this subsection shall prohibit a person from storing a firearm within a motor vehicle while the vehicle is on these grounds or areas. Nothing contained in this section prohibits municipalities or counties from exercising powers provided by law in declared states of emergency under Article 36A of this Chapter.