Laser Searches for Downed Aircraft

Aaron J. Hand

When it comes to finding downed airplanes or sinking boats, time is critical. The faster rescuers locate the disabled vehicle, the better the chance of finding survivors. Researchers at Daedalus Enterprises Inc. are working on a system that lets lasers do the searching -- a system that promises to be more reliable and faster, and to enable searches in both day and night conditions.

Using a laser scanner from Daedalus, searchers could locate a disabled vehicle fitted with retroreflector markers.

Current mandates require all aircraft to carry emergency locator transmitters and all watercraft to carry personal emergency beacons, both of which send distress signals out through satellites in an emergency situation. A major problem with this system, however, is that 90 percent of alarm signals are false, according to Col. Bill Charles, commander of the Michigan wing of the Civil Air Patrol, a national organization that conducts about 85 percent of the search-and-rescue missions in the continental US. For example, false alarms might be triggered by high winds, hard landings or even by operators unwittingly playing with the instruments, he said.

Unlike beacons, Daedalus' system requires no active participation from the distressed vehicle. The system incorporates a laser scanner carried by the searching vehicle, and retroreflector markers measuring about 1 square foot attached to the disabled aircraft or watercraft. The laser is eye-safe from a certain distance and is automatically disabled when it reaches a point that would no longer be safe.

The Civil Air Patrol sees the laser search-and-rescue system as a promising development, according to Charles. "We're anxiously awaiting further testing on it because we see great applicability in search and rescue," he said, noting an additional way it could be used: "You could put the marking material on the inside of a rescue vest, and a hunter could lay it out on the ground when he's lost and knows he's in trouble."

Smaller, more efficient

Daedalus already has developed a prototype laser search-and-rescue system that weighs about 200 lb and draws about 1.2 kW of power. Now the company is working on a similar system that should be less expensive, use less power and weigh less, although researchers do not yet know what final specifications they will achieve, according to Charles G. Stanich, vice president of research and development for Daedalus.

Reducing the size and cost of the instrument would help enable its installation on such light aircraft as the Cessna-172 used by the Civil Air Patrol or the HH55 helicopter used by the US Coast Guard. The Civil Air Patrol would like to see Daedalus get the whole instrument down to about 100 lb, Charles said.

Ultimately, Daedalus will need legislative help for its instrument to succeed. "It could only become successful if there's a mandate to use retroreflectors," Stanich said.

To that end, Daedalus hopes to conduct a feasibility demonstration of its product in Alaska, where the system could prove particularly useful in wilderness areas.