May 12, 2010: Last month, the U.S. Army conducted tests of a helicopter UAV parachuting supplies. The K-MAX UAV was originally designed as a single seat helicopter that could carry sling loads of 2.8 tons (6,000 pounds) at sea level, or two tons (4,300 pounds) at 4,800 meters (15,000 feet). The recent tests involved using the army low altitude parachute, which can deliver loads of 36 kg (80 pounds) to 273 kg (600 pounds) at heights of 48-100 meters. The K-MAX had a special rig that could carry and release four different payloads, and demonstrated its ability to drop each one at a different location. The low altitude drops are more accurate than higher altitude ones, and useful where the troops getting the stuff are on hilly ground that has few good helicopter landing zones. The army is also planning to test using K-MAX to drop loads from higher altitudes, using GPS guided parachutes.

Earlier this year, the U.S. Marine Corps successfully tested K-MAX landing supplies. A year ago the marines began 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, but no one was able to come up with anything in time. Some firms told the marines they were working on it, and one of these outfits, Kaman, modified its K-MAX manned helicopter to meet marine requirements.

The 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).

The manufacturer has flown the K-MAX over 400 hours so far, and the manned K-MAX has logged over 250,000 hours worldwide. Now the marines have to decide if they want to buy the K-MAX UAV, how many and how soon. The army and SOCOM (Special Operations Command) are also interested in K-MAX, and other helicopter UAVs, for delivering supplies in places like Afghanistan.