Boeing said that A160 Turbine (A160T) Hummingbird unmanned rotorcraft has achieved two major goals. First, the 35-foot-long rotorcraft has successfully shifted gears using its two-speed transmission while in flight. Second, the A160T has logged more than 100 hrs flight time.
The successful gear-shifting is an important aspect of the A160T’s performance package, which is designed to support long endurance flights in a variety of conditions and altitudes. Another important (and related) element is the rotorcraft’s "optimum rotor speed technology." This allows the A160T to alter the RPMs of its 36-foot-diameter rotor to best suit the aircraft’s flight requirements.
"Being able to shift gears in flight is the final significant step in realizing the full potential of our optimum speed rotor technology, which enables game-changing capability for the warfighter," said John Groenenboom, A160T program manager for Boeing. "It allows us to significantly expand the flight envelope at higher gross weights and at higher speeds, while maintaining the A160T’s world-record-setting endurance. We now have an unmanned air system with the performance of a fixed-wing and the precision and versatility of a rotorcraft."
As UAVs go, the A160T Hummingbird is a warhorse. It is designed to fly 2,500 nm for more than 24 hrs, carrying a payload exceeding 300 lbs. The A160T’s estimated top speed is 140 kts at ceilings up to 30,000 ft; about 10,000 ft higher than conventional helicopters can fly today.