Prachi Patel at the Institute of Electrical & Electronic's Engineers (IEEE)
web site has a
5th April 2019 report on the maiden flight of the
Sikorsky-Boeing's Defiant helicopter two week's ago.
It is one of several rotary wing aircraft competing to replace the US
Army's ageing Black Hawk fleet.
Quote:
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Originally Posted by Prachi Patel
The Defiant is based on Sikorsky’s experimental X2 technology, which holds the record for being the fastest helicopter technology in the world. A demonstration craft reached 435 km/h in 2010, beating the 1986 record of 400 km/h by the Fédération Aéronautique Internationale.
“The Defiant design represents a leap forward in vertical lift technology,” says Boeing spokesperson Randy Rotte. “While it can fly at nearly twice the speed and has twice the range of conventional helicopters, it retains the very best, if not better low-speed and hover performance of conventional helicopters.” The Black Hawk has a top speed of about 290 km/h and combat range of 580 km.
The craft’s unconventional design consists of dual coaxial main rotors—two rigid rotors that spin around the same axis in opposite directions—and a push propeller in the rear. This combination provides unique capabilities. The powertrain distributes engine power between the main rotors and the rear propeller, says Rich Koucheravy, business development director on the Future Vertical Lift program at Sikorsky, which is part of Lockheed Martin. “For example, the allocation of main rotor thrust and prop thrust may be different during a high speed flight and a low speed, high G maneuver,” he says. This means the pilot can efficiently operate the aircraft during both conditions.
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Full story and video here :-
https://spectrum.ieee.org/tech-talk/...r-first-flight
