Powered by quiet motors and armed with conventional and infrared cameras and other specialized sensors, unmanned aerial vehicles (UAVs) are becoming more and more attractive to law-enforcement agencies. Not surprisingly, both the FBI and the Office of Homeland Security are investigating how they might use UAVs for covert surveillance of suspected criminal or terrorist activity in the U.S., by night and day and in all-weather conditions.

But UAVs are going to be a headache for air traffic control. Clearly, they will not be operated on published flight plans and their areas, altitudes and times of operation will hardly be the subject of widely disseminated notams. There are other considerations, too, such as recovery plans if the datalink controlling the UAV’s flight path should fail. For these reasons, the FAA has asked FBI and Homeland Security officials to define automatic diversion procedures for all UAVs they plan to use in domestic U.S. airspace.