October 19, 2007: For seven years, the U.S. Department of Defense has been developing a helicopter UAV that can stay in the air for over twelve hours at a time. The most recent test had this A160T Hummingbird (PHOTO) staying in the air for 12 hours, at 5,000 feet, while carrying a 500 pound load (to simulate a typical sensor package). When the A160T landed, it still had 40 percent of its fuel. The next test will be for 18 hours, with a 300 pound load. The first flight test of the Hummingbird Unmanned Aerial Vehicle took place five years ago.

The A160T is a small helicopter, able to fly under remote control or under its own pre-programmed control. The 4,000 pound vehicle has a top speed of 240 kilometers an hour, and was originally designed to operate for up to 40 hours carrying a payload of 300 pounds. Maximum altitude was to be about 30,000 feet, and its advanced flight controls were to be capable of keeping it airborne in weather that would ground manned helicopters.

The original A160 used a commercial 300 horsepower automobile engine. This enabled better control over speed, since turbines must run at nearly the same speed all the time. A piston engine can idle at 50 percent power. That control made the UAV better at what helicopters do best, just stay in one place. The A160T uses a 700 hourse power gas turbine and new gearbox. That long endurance was to translate into 4,500 kilometers range. After the first flight test, it was believed the aircraft might be ready for production by 2006. That was too optimistic. Helicopters are complex beasts, and things take longer.

Currently, a production decision is not expected for another year or two. If the Hummingbird does get into production, it will make a very useful UAV for stakeouts, watching for the enemy to make a move. The Hummingbird will also be armed, most likely with hundred pound Hellfire missiles, or 44 pound Viper Strike smart bombs.