Wednesday, October 1, 2008
Rotorcraft Report: X2 Flight Caps Week of Sikorsky Firsts
The maiden flight Aug. 27 of Sikorsky Aircraft’s X2 technology demonstrator (shown right, with an S-76 chase aircraft) was the most notable of first flights the Stratford, Conn. manufacturer achieved in that busy last week of August.
Aug. 29 saw the debut of the fly-by-wire version of the company’s UH-60M upgrade of its Black Hawk for the U.S. Army (shown below). In between those dates, Sikorsky flew the first Naval Hawk, an S-70B, built at its new Military Derivatives Completion Center of the Hawk Works @ Schweizer Aircraft, its subsidiary in Horseheads, N.Y.
Schweizer, acquired by Sikorsky in 2004, is also the parent company’s rapid-prototyping center and was the site of Sikorsky Chief Test Pilot Kevin Bredenbeck’s first flight of the coaxial-main-rotor, compound X2. Schweizer has been the base for X2 development since the program was launched in 2005.
Bredenbeck’s first flight lasted about 30 min, during which he maneuvered through hover, forward flight and a hover turn. The aft propulsor was not engaged for the first flight.
That flight came later than the goal set at the program’s launch, which was to fly by the end of 2006. But the flight tests seemed to progress steadily once the aircraft was flying. Plans had called for 25 or so flight tests at Schweizer under Phase 1, covering flight from hover to 40 kt forward speed, before the sole prototype was to be moved to Sikorsky’s flight-test facility in West Palm Beach, Fla. By Sept. 18, program officials were preparing to pack the X2 up for the move down south.
At West Palm Beach, the X2 is to undertake the second, third and fourth phases of the flight test program, which would progress from 40 to 120 kt, then to 180 kt and finally the program goal of cruising at 250 kt.
That speed goal is just one of four key performance parameters for the program. The others are low acoustics, low vibration levels in flight and low pilot workload.
The first X2 flight culminated more than four years of design, development and testing of the demonstrator aircraft’s suite of technologies, which Sikorsky is pursuing prove its proposition that it can nearly double a helicopter’s traditional cruise speed limit of 150 kt (hence X2) while retaining conventional helicopter attributes such as hover, low-speed handling, autorotation and a simple transition to forward flight. "X2 Technology has crossed a major threshold," Sikorsky President Jeff Pino said of the first flight. "The team’s achievement sets the stage for the next series of tests eventually leading to maximum speed. It also sparks the imagination for what ultimately the technology can mean to the future of the rotorcraft industry. We are far from having a product, but closer than ever to realizing the potential."
In the roughly 60-min flight test of the fly-by-wire UH60M at West Palm Beach, Sikorsky test pilots Mike Skaggs and Steve Silder maneuvered the aircraft through hover, forward flight, and a hover turn.
Col. Neil Thurgood, the army’s Utility Helicopter Project manager, said, that aircraft’s first flight "represents the next step in providing the U.S. military the best capability to execute its mission. This aircraft contains dramatic technological advances, yet retains and improves on the proven design of the world’s most capable and robust utility helicopter."