You won't see unmanned drones flying at US civilian airports. Nor, in most cases, anywhere in US civilian airspace. Drones aren't allowed here because we don't know how to safely integrate them into civilian airspace. There's a controversial effort inside FAA to come up with rules for UAVs and it's going very slowly and carefully. The arrogance of us flying drones in Djibouti and Seychelles civilian airspace when we won't let them in our own airspace is pretty amazing.