There is no lighting inside airport buildings and control towers etc.
Either we need a module that can toggle lights in nearby buildings or critical lights in airport buildings need to be on by default. Airfield buildings such as the control tower, and some hangars, barracks etc. need to be set on.
You need to do that manually yourself when you create a mission. Imagine Altis with a zillion lights on by default and the fps you will get then.
@B00tsy - before just spouting off maybe your should check your facts first. Currently it seems we can target certain lights like street lights but not the lights in the Airport buildings.
As indicated we either need a module to toggle lights in a demarcated area so we can simulate a black out or have the ability to toggle the lights in certain buildings. Airfields are critical areas for mission builders. This has a duplicate ticket 0013489.