The Raider — a high-speed, coaxial-rotor compound helicopter based on the company’s X2 technology demonstrator — flew for approximately an hour, performing a variety of low-speed maneuvers and three takeoffs and landings. On board were S-97 chief pilot Bill Fell as well as former X2 test pilot Kevin Bredenbeck, serving as co-pilot.
According to Fell, the fly-by-wire Raider was “rock-solid” during its first flight, performing largely as expected.
“We put a lot of investment into simulation and our software integration lab, and we’ve spent hundreds of hours in those labs and simulators developing the control laws,” he said. “So we were very happy when we lifted the aircraft into the air, it was almost exactly like the software lab — the one benefit being that we have better visual cues.
“We were able to march through the [flight test] card almost precisely like we did in simulation and get all of the data we desired,” he continued. “We’re excited to get on to the next flight and really expand the envelope.”
Friday’s flight launches a flight-testing program that is expected to last about a year, during which the Raider is expected to demonstrate high-G maneuvering and cruise speeds of up to 240 knots. On this first flight, the aircraft’s rear pusher-propeller — which enables maximum speeds well in excess of those of conventional helicopters — was intentionally spinning but not engaged.
“As we go through envelope expansion we will engage the prop and do the higher-speed portions of the envelope,” said Mark Miller, Sikorsky vice president, Research and Engineering.
Originally developed to compete for the U.S. Army’s Armed Aerial Scout program — which is now on indefinite hold — Raider is being self-funded by Sikorsky and 53 industry partners. A second Raider prototype is currently under construction, with final assembly expected this year. Sikorsky is planning to use that aircraft for a demonstration tour in 2016.
The Raider was initially projected to fly by the end of 2014, but Miller said that the use of new technologies and manufacturing techniques, such as additive manufacturing, delayed that ambitious timeline.
“This is not just a new helicopter,” he explained, “it is a testbed for the development of a lot of new technologies and some of those took a little longer.” On the positive side, he said, Sikorsky’s rigorous approach to introducing those technologies should “enable us to go fast on the back end . . . We took a little bit longer than we advertised for the first flight, but I think we’re going to move very smartly through the test program.”
Miller also noted that the approximately 11,400-pound (5,170-kilogram) gross weight Raider will serve as a “risk reducer” for the SB-1 Defiant, the larger coaxial-rotor compound helicopter that Sikorsky is developing with Boeing for U.S. Army’s Joint Multi-Role Technology Demonstrator program. Sikorsky and Boeing anticipate first flight of the SB-1 in 2017.
“The Defiant platform will leverage and take advantage of the capabilities that are being demonstrated on the Raider program,” Miller said.
The Raider's first flight lasted approximately an hour, during which it performed a variety of low-speed maneuvers and three takeoffs and landings.