Domestic unpiloted aircraft may use tunneling' to fly in national airspace.

• Author: Magnuson, Stew
• Position: SECURITYBEAT

* While unmanned aerial vehicles are common in the skies above Afghanistan and Iraq, they have been flown sparingly in the United States because of strict Federal Aviation Administration rules regulating national airspace.

Police agencies would like to use remotely controlled aircraft to monitor cities. Customs and Border Protection has employed them along the U.S. borders with Mexico and Canada, but the Department of Homeland Security would like to expand their applications by flying them to disaster zones in times of emergency.

Standing in their way is the FAA, which has a duty to prevent aviation-related accidents.

One of the key sticking points has been the ability of the remotely piloted aircraft to sense and avoid other aircraft or obstacles in low altitudes.

The Army may have a solution to the problem.

A ground-based system of radars or other sensors peering up at the UAV and the airspace surrounding it could help escort a pilot-less aircraft to its destination, said Viva Austin, product director for unmanned systems airspace integration concepts at the Army aviation bureau.

The concept is called "tunneling," which requires the setting up of safe corridors through airways and the pre-placement of sensors at points along the way. If an object is detected, the radar nodes would send a command to the UAV for it to move out of harm's way.

Previous concepts called for placing sensors aboard the aircraft. The military has been working on onboard solutions for years, but so far no technologies have emerged that fit the FAA's stringent requirements.

The military has a...