Sikorsky Aircraft chief test pilot Kevin Bredenbeck flew the company's X2 advancing blade concept demonstrator for the second time on 18 September at the company's Elmira facility, accumulating 25min of additional flight time beyond the 48min first flight on 27 August and testing a desensitised version of the fly-by-wire control system.
Jim Kagdis, Sikorsky's manager of advanced programmes, says data from the first flight was replayed on a high-fidelity ground simulator at Sikorsky's main facility in Connecticut that includes aircraft control feel. Flight-control gains in all three axes "were modified accordingly" in the simulator and tested on the aircraft.
"On the second flight, the controls were much more comfortable," says Kagdis. Bredenbeck performed similar manoeuvres as on the first flight - 20kt (37km/h) forward flight, 10kt sideward and rearward and low-speed circuits around the airport. Kagdis says the flight was cut short because winds started to pick up.
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Sikorsky plans to build 3h of flight time before grounding the coaxial rotor high-speed helicopter to integrate the pusher propeller into the power train and control system for faster flights planned in phases two, three and four in West Palm Beach, Florida. Kagdis says the pusher system should be integrated by year's end, after which the remainder of the 15h in phase one will be completed in Elmira.
Phase two will see the aircraft flying as fast as 80kt without the aid of the pusher prop. In phase three, test pilots will engage the rear propeller to attain speeds of 120kt, In stage four, Sikorsky will attempt to reach 250kt or more.
Source: Flight International
