The U.S. armed forces used unmanned aerial vehicles (UAVs) during the Vietnam War, when the Teledyne Ryan AGM-34 was deployed for reconnaissance, surveillance, and electronic intelligence-gathering tasks. Since then, ship-- and ground-launched UAVs have taken on more active combat roles, including artillery spotting, target acquisition, and use as decoys to distract the enemy and give manned aircraft a better chance of survival. The U.S. Army Dragon UAV is even capable of jamming enemy tactical radios. Given the threats at every level of warfare, future development no doubt will emphasize UAV suppression of enemy air defense and strike missions, and coverage of areas contaminated by biological and chemical agents.
Unmanned aerial vehicles are not meant to replace manned aircraft at this stage; rather, they are valuable supplements to both air and surface manned systems. Their military and civilian potential is growing rapidly and should be recognized by the agencies responsible for search-and-rescue (SAR) functions-especially the U.S. Coast Guard.
There are six clear advantages to using UAVs in the SAR role:
* Controllers, such as Coast Guard groups or cutters, could launch a UAV to take a "first look" at the rescue area before committing unprepared manned aircraft and vessels to harsh weather conditions or hostile enemy force. The UAV could go to the scene prior to a piloted aircraft and relay information about the nature of the distress. Two years ago, a helicopter crew from a Coast Guard air station was sent into hurricane conditions to rescue people reportedly being "swept away" in rising floodwaters. The crew, after flying low over land in onequarter mile visibility and hurricane-- force winds, arrived to find the people already had been rescued by ground personnel and their vehicles were hardly in danger of being lost. By using an unmanned vehicle in this situation, the Coast Guard would have prevented what turned out to be a needless risk of crew and aircraft. The UAV could pass weather information and the status of survivors to the SAR unit; if so equipped, the UAV could deploy a datum marker buoy to provide water current information. This would enable crews to estimate the situation more accurately and develop their SAR plan while en route. In combat, UAVs could identify enemy positions and divert their attention-and incoming fire-from the rescue operation.
> On locating survivors, the UAV would provide a continuously updated position to the rescuers. This is critical when survivors are caught in swift currents or are so far from shore that it might take hours to reach them. For an unmanned vehicle to be of best use in this scenario, it must be capable of high speeds to reach the scene quickly, yet be able to maintain a much slower speed-or hover-over the distress site. Because of its tilt rotor technology, the Bell Eagle Eye UAV would be ideal for the SAR role.
> Assuming the people in distress have a working radio, the UAV could provide a communications relay platform to incoming SAR crews. Pilots and other controllers would be able to begin conversing with the survivors, and forwarding rescue intentions and instructions much sooner.
> If survivors are aware of being spotted, the UAV also would give them a psychological boost. They would realize that rescue efforts were underway. At the same time, a suitably outfitted UAV could drop limited amounts of water, food, and ammunition to them as they await rescue.
> A UAV could be launched from onscene aircraft that have to return to base for fuel or mechanical failure. For example, a fixed-wing plane is vectoring helicopters to the rescue site when one of its key systems breaks down and it heads for home. Rather than leaving survivors without coverage, it launches a UAV to continue holding over the survivors and passing updated positions to the rescuers.
> Use of UAVs in conjunction with manned platforms allows rescuers to cover more area in less time. When vessels scheduled to cross many miles of water are overdue, a huge search area normally is generated. It could be covered more effectively and quickly by UAVs operating in concert with other SAR efforts.
Cost is the chief drawback in employment of unmanned aerial vehicles for SAR functions. Service requirements probably would result in larger and more complicated systems. To be flown from most ships, UAV avionics would have to be designed so that a crewman with no flying experience could pilot the craft successfully. A cargo capability would mean increased size, weight, and complexity. Finally, there would the additional costs of training and maintenance.
Conclusions
Regardless of additional costs, unmanned aerial vehicles are proven tools that show great promise. With continued research and technological advances, they could soon become vital assets. As a matter of priority, the Coast Guard should formally assess the utility of UAVs-principally the tilt rotor Bell Eagle Eye-with a view toward including them in its future SAR program.