Coast Guard's unmanned aircraft set for testing.

Prototypes of the Coast Guard's unmanned tilt-rotor aircraft are to be flown in February, according to officials, who add that a number of operational questions remain outstanding.

Future use of the system, called Eagle Eye, depends on drafting rules to operate in airspace used by commercial air traffic and ensuring that sensors perform at high altitude, said Cmdr. Melissa Bulkley, who was detached to fly wartime unmanned aerial vehicle (UAV) missions in the Persian Gulf and serves as the Coast Guard aviation representative for the Deepwater maritime security transformation program.

"We're still in the design and demonstration phase," she said at a recent aviation industry conference briefing. Bell Helicopter Textron is scheduled to deliver the UAVs for deployment in 2008.

The sensor and air confliction issues became clear when the choice was made to keep line-of-sight communications instead of using satellites, Bulkley said, which increased the altitude at which the craft would be operating.

"The farther away the UAV is, the higher the minimum altitude has to be," she explained. Since the craft was designed with a range of 100 nautical miles, it must be able to operate at 18,000 feet to preserve the line of sight.

The Eagle Eye can fly at 20,000 feet, but some of its payload can't handle those heights. "Sensors have to be able to operate at those higher altitudes," Bulkley said. Sensors include electro-optics and infrared, as well as radar.

The increase in altitude puts these UAVS in the same space as commercial flights, a vexing problem that has yet to be resolved. "We're working with private companies to crack these airspace issues," Bulkley said. These airspace conflictions are affecting payload decisions, she said, including the inclusion of air-to-air radar and video packages that could avert a collision.

Capt. William Peterson, chief of USCG's office of aviation, added that he is working with other Department of Homeland Security agencies, such as Immigration and Customs Enforcement, for common operating procedures on the safe domestic use of UAVs. ICE currently is testing unmanned aircraft to increase situational awareness along the northern and southern borders of the United States.

The Coast Guard would be launching Eagle Eye UAVs from the larger national security cutters. The service's overall modernization program, called Deepwater, envisions a more robust Coast Guard with greater capabilities to halt terrorists, board boats and bring lethal force to bear on threats. The UAV component helps the agency meet the greater demands placed on it, while maintaining its traditional role in search and rescue, environmental crime prevention and overall maritime law enforcement. Eagle Eye is intended to be used to scope out suspicious ships, while small boarding craft or helicopter units wait to act on standby.

Bulkley and Peterson both said there is no plan yet to arm the Eagle Eye, even though a weaponized version being tested for the Marines in conjunction with the Coast Guard may be equipped with weapons. A laser designator is light and easy to install, it is a comfortable fit for the aircraft, Bulkley noted.

Designers of Eagle Eye also had to consider the tight quarters on the cutters on which they will deploy and the needs of maintainers who put one hour of work per flight hour into the UAV. Bell came up with a design that allowed the tail and nose to be folded. The ability to open the nose gives specialists access to the sensors, to retrieve and configure the array, while granting maintainers easy access for cleaning and replacing parts, Bulkley said. The craft can operate in any weather a helicopter can, she added.

It has not yet been decided if one or two operators would be necessary to fly the Eagle Eye, but two maintainers would be assigned.

The Bell Eagle Eye UAV system has been in development since the mid 1990's. In 1998, it completed a technology maturity test in Yuma, Ariz. The Coast Guard awarded the program in February 2003, and so far it is mainly on schedule. More flight tests are planned between March and June 2007, Bulkley said.

Each Eagle Eye costs $5.5 million, including the sensors, she added. The most attractive attribute of the UAV is its maximum speed of 185 knots. The craft is designed to travel 100 nautical miles, spend three hours in surveillance, and return to the ship with 20 minutes of fuel to spare. It is not controlled by a joystick, but rather takes computer console instruction and "flies itself," Bulkley said.

Eagle Eye has a wingspan of 15.2 feet, is 17.9 feet in length, and is nearly 6 feet high. It has the appearance of a conventional fixed wing aircraft, but with tilt rotors at the end of each wing, it can maneuver up or down and hover.

"There is no reason to hover, other than take-off and landing," she added. "When it acquires a target it can make a slow orbit overhead at 85 to 110 knots."

When asked if Eagle Eye could be recovered following a crash in the water, she said the composite aircraft would likely be demolished and lost. "It sinks," she said. "The best you could hope for, anyway, would be to recover the sensors."