December 10, 2010: The U.S. Marine Corps has ordered four UAV type cargo helicopters, and is sending them off to Afghanistan for field tests. Two of these are Boeing A160Ts, and two are Lockheed K-MAXs. These two models are the finalists in a competition that has been under way for over two years.

It all began in 2008, when the marines went shopping for a UAV to deliver supplies, at least half a ton per trip, in order to get essential items (ammo, water, food) to combat troops in remote locations. The marines wanted the UAV in action within six months, and hoped to find something that already existed. They believed that most likely candidates would be helicopter UAVs, which could land wherever needed.

For the last decade, the U.S. Department of Defense has been developing a helicopter UAV designed to stay in the air for over twelve hours at a time. At that time, this A160T Hummingbird had stayed in the air for 18.7 hours, at altitudes up to 15,000 feet, while carrying a 137 kg (300 pound) load (to simulate a typical sensor package). The first flight test of the Hummingbird Unmanned Aerial Vehicle took place eight years ago. From the start, the A160T was a contender for the marine contract.

The A160T is a three ton helicopter, able to fly under remote control or under its own pre-programmed control. The UAV has a top speed of 255 kilometers an hour, and was originally designed to operate for up to 40 hours carrying a payload of 127 kg. Maximum altitude was to be about 10 kilometers (30,000 feet), and its advanced flight controls were to be capable of keeping it airborne in weather that would ground manned helicopters. The marines came along just as the A160 was completing development and ready for production. The marine version can be configured to carry a half ton (500 kg) of cargo for several hours.

The Lockheed K-MAX is a 5.4 ton helicopter with a cruising speed of 148 kilometers an hour and an endurance of over six hours. It can carry up to 2.7 tons slung underneath. This made the K-MAX an ideal candidate for the marine UAV. When the K-MAX UAV was tested, it successfully met the marine requirements. It was able to carry a 680 kg (1,500 pound) sling load to 12,000 feet (3,900 meters), and hover. It was able to deliver 2.7 tons of cargo, to a point 270 kilometers distant, within six hours (two round trips). The K-MAX UAV can also carry up to four separate sling loads (totaling 1,568 kg, or 3,450 pounds).

After two of each of these UAVs spend six months in Afghanistan next year, the marines will decide which one to buy, how many and how soon.