Undersized drone promises extended maritime surveillance.

• Author: Peck, Michael
• Position: UPFRONT

It looks like a cross between an airplane and an artillery shell, but a 12-pound unmanned aircraft named Coyote may prove to be a potent tool for maritime surveillance.

Coyote, five feet long and with a wingspan of 30 inches, is designed to be dropped from sonobuoy launchers on the Naw's P-3C Orion antisubmarine aircraft. Using a single rear-mounted propeller powered by an electric motor, the aircraft has an endurance of about 90 minutes at a cruise speed of about 52 knots and a range of about a hundred miles.

With the folding wings extended, the craft is roughly H-shaped. Coyote carries an electro-optical or infrared camera in its nose. Maximum payload is 5 pounds, though a typical load would be 2.5 pounds. A P-3 can carry 48 external and 36 internal sonobuoys. Modified Coyotes can be launched from external racks, but the Navy hasn't get asked the manufacturer to add the capability.

Coyote is designed to provide a standoff surveillance capability for aircraft, according to Lars Studley, lead design engineer for the vehicle's manufacturer, Advanced Ceramics Research of Tucson, Ariz. The GPS guidance allows the operator to just "load up a mission, choose the area they want to look at, and then hit the fire button," said Studley. "It flies itself to that location, and they're able to use the camera to decide what they want to look at."

Like standoff weapons on strike aircraft, a standoff surveillance unmanned air vehicle, or UAV, protects valuable manned aircraft and crews. Instead of having to descend to visually check out a target, the launch aircraft can remain at a distance. "If P-3 receives radar or sonar data of vessel, rather than have P-3 fly potentially into harm's way, they can launch the UAV, which collects and sends imagery back to the P-3, and allows it to remain at high altitude" Studley said.

But therein lies the design challenge. For this concept to work, the UAV has to be small enough to fit in a narrow sonobuoy tube that's less than 3 feet long and 4.5 inches wide. Yet the vehicle must be strong enough to withstand the stresses of high-speed, high-altitude launch. UAVs have previously been launched from transport aircraft, but they were larger vehicles operating under less severe launch conditions, Studley said

Coyote solves the size problem by fitting the vehicle inside a canister. The launch procedure begins with the flight crew inserting the canister inside a sonobuoy tube. When it is fired out of the tube, a parachute...