I doubt you'll find it in the NEC. This would be required by the FAA. The large international airport in our area has generators at every airfield lighting vault. In the event of a power failure the generators come on and all the lights on the runway, taxiways, ramp areas and gate areas come on, including all aircraft signs and warning beacons. As explained to me, the FAA wants the lights on no matter what, for obvious safety reasons.
As far as special requirements, check the FAA website for the ACC (AC?) codes (these codes run the entire airfield area and have details for everything). Even better to contact the FAA.