The Defense Advanced Research Projects Agency has conducted the first flight test of the Hummingbird Unmanned Aerial Vehicle. This is a small helicopter, able to fly under remote control or under its own pre-programmed control. The 4,000 pound vehicle is designed to fly at 135 knots and to operate for up to 40 hours carrying a payload of 300 pounds. Maximum altitude is expected to be about 30,000 feet, and its advanced flight controls should allow it to operate in weather that would ground manned helicopters. Hummingbird is powered by a commercial 300hp automobile engine. Using a piston engine rather than a turbine allows better control over its speed, since turbines must run at nearly the same speed all the time but a piston engine can idle at 50% of its maximum RPMs. The Army and Special Operations Command are expected to be the first customers but the Navy is also interested.--Stephen V Cole