Military tests unmanned helicopters to reduce supply risks

For as long as there's been war, there's been the challenge of military supply—making sure that the men and women on the front lines, the people in harm's way, have what they need when they need it. The art and science of logistics grew up around that problem, and the work to develop faster, better, safer methods continues to this day.

In recent years, escalating threats to supply lines in Southwest Asia have lent urgency to that mission. Concerns about enemy attacks have led the U.S. military to step up efforts to reduce the risks that come with moving cargo across often hostile and unforgiving territory. Those efforts have yielded a number of innovative tactics and technologies aimed at protecting lives. They include a robotic lift truck designed for use in high-risk environments (see "Military, academic researchers successfully test robotic lift truck") and initiatives to conserve water and fuel at operating bases in Afghanistan in order to reduce the need for supply convoys (see "For U.S. Marines, going green can save lives," May 2010 www.dcvelocity.com). But there's more to come. Within the next year, the military expects to put its latest technological breakthrough into action: unmanned helicopters capable of carrying pallet-loads of supplies to posts in remote locations.

Infrastructure "almost nonexistent"
To understand what's driving this initiative, it helps to know a little about the supply challenges the military faces in Afghanistan. One of the biggest difficulties is the country's limited infrastructure. In most parts of the world, getting food, munitions, and so forth out to the troops is a simple matter of throwing supplies in the back of a truck and hitting the road. But in Afghanistan, roads aren't always a viable option, largely for reasons of safety. To put it bluntly, Afghanistan's roads are a very dangerous place—roughly 60 percent of all military casualties are from Improvised Explosive Devices, commonly known as IEDs. In fact, IEDs are the number one killer of troops, security forces, and civilians.

Even if the safety threats could be eliminated, Afghanistan's road network leaves something to be desired. The roads themselves are rudimentary, and they don't always go to the sorts of places the U.S. military wants to go. As Alan Estevez, acting assistant secretary of defense for logistics and materiel readiness, puts it, "Infrastructure in Afghanistan is almost nonexistent."

Adding to the problem is a lack of alternatives to over-the-road moves. The landlocked country has no seaports, no railroads, and no navigable rivers. That leaves air as the only other option, and there are a number of difficulties with regard to conventional air resupply. Afghanistan has just 16 airports with paved runways, and only four of those can accommodate international cargo shipments. Building more runways or even small landing zones would be impractical because of the country's mountainous terrain.

Other options are also problematical. In some remote locations, the military uses guided parachutes that can follow a radio beacon to a target. But these parachutes are vulnerable to wind currents, and in mountainous Afghanistan, wind is a near constant.

Manned cargo helicopters can carry loads slung under their bellies, but cargo helicopters are vulnerable to attack. Even small arms fire can put pilots and their crews at risk.

Testing under way
That last obstacle is one the Navy thinks it can overcome. The answer, it says, is an unmanned helicopter, which it calls "a vertical lift Cargo UAS [Unmanned Aerial System]." In a draft document issued by the Naval Air Systems Command this past summer, the Navy laid out its requirements for this "aerial system": It has to be able to reach an altitude of 14,000 feet while carrying 750 pounds of cargo loaded on a standard wood pallet. In addition, the helicopter must have a roundtrip range of 125 miles, including a 20-minute fuel reserve.

This is no whiteboard exercise. Prototypes have already been built, and testing is under way. Earlier this year, the Marines conducted successful tests of two different unmanned cargo helicopters at the U.S. Army's Dugway Proving Ground in Utah, using sling loads to accomplish resupply. (Dugway was chosen for its similarity to Afghanistan with respect to terrain, weather, and altitude conditions.) One of the helicopters was the K-MAX BURRO, an unmanned helicopter developed by Lockheed Martin Corp. and Kaman Aerospace. The other was Boeing's A160T Hummingbird.

Both vehicles met or exceeded requirements. According to documents provided by one of the participants, tests of the unmanned cargo helicopters showed they could hover at 12,000 feet with a 1,500-pound sling load, deliver 3,000 pounds of cargo within six hours to a forward operating base more than 75 miles from the supply point, and fly under remote control in both day- and nighttime conditions. The test results were good enough that the Department of the Navy has gone ahead with the next step. It has begun work on a request for proposals to deliver and deploy the equipment next year.

The Marines (which are part of the Navy Department) expect to award a contract around the end of 2010 for combat-ready unmanned cargo helicopters. These aircraft are expected to see action in Afghanistan by the summer of 2011.