Saturday, July 15, 2017

Sikorsky aims high with experimental aircraft

It was a lofty moment just over two weeks ago for Sikorsky Aircraft after a pilot took off to fly the new King Stallion helicopter cross-country for the first time — the biggest ever built for the U.S. military and the first of three major new programs nearing full production.

It is the coming maiden flight of an experimental aircraft, however, that will determine the heights Stratford-based Sikorsky can hit later this century — if Pentagon planners climb on board.

Archrival Bell Helicopter plans to begin flight tests by September of its entry in a Department of Defense competition to determine the base design parameters DOD will use for rotorcraft — ranging from heavy-lift models like today’s CH-53K King Stallion to all-purpose workhorses like the Sikorsky Black Hawk — to combat aircraft like the Boeing Apache.

Against the Bell V-280 Valor tilt-rotor prototype in the Pentagon’s Future Vertical Lift fly-off, Sikorsky and Boeing are teaming up on the SB>1 Defiant. The companies have yet to make public any flight test schedule for the aircraft, but they’re not expected to begin until next year, according to the FlightGlobal aviation trade publication.

If running behind Bell’s schedule, Sikorsky has already test-flown a similar prototype in its S-97 Raider, which, like the SB>1 Defiant, features a “pusher prop” on the tail boom mounted in the same orientation as a propeller on an airplane wing. On top, stacked sets of rotors whirl in opposite directions, a concept familiar to model helicopter enthusiasts and with which Sikorsky itself had experimented at scale in the 1970s with its S-69 prototype aircraft.

Bethesda, Maryland-based Lockheed Martin is counting on continued Black Hawk sales and the CH-53K program to maintain its Sikorsky subsidiary in the coming decade, with the U.S. Marine Corps wanting more than 200 King Stallions. Two more programs are on the taxiway pending final federal approvals and funding: a fleet of new presidential helicopters for the White House and one for the U.S. Air Force to conduct search-and-rescue operations for downed pilots and other operations over hostile territory.

But on beyond, Lockheed Martin is hoping the Future Vertical Lift program can accelerate Sikorsky similar to how did the Black Hawk and its variations, which sustained the Stratford manufacturer over four decades as the military’s base utility helicopter in the post-Vietnam era.

The vision is a new category of rotor aircraft that can blow by the Black Hawk for speed, range and payload capacity, with the ability to operate in extreme conditions and to be controlled remotely with no pilot on board. The Department of Defense wants aircraft that will be cheaper to operate and maintain over the 40 to 60 years it expects to field them, and wants to be able to use the winning platform in the design of everything from truck-toting beasts akin to the CH-53K to nimble aerial scouts.

In the digital flight simulator, the SB>1 Defiant exhibits revolutionary flight characteristics, according to Frank Conway, a Boeing experimental pilot who spoke last October at the annual meeting of the Association of the United States Army, while showcasing an SB>1 flight simulator to the trade publication IHS Janes.

“What that pusher prop ... allows us to do is both rapid acceleration and deceleration with a level body,” Frank Conway said. “Another unique thing I can do is actually decelerate with the nose pointing down, which is not a typical, helicopter-type profile. ... We’re basically hanging on the prop from behind.”

That pusher prop can also drive SB>1 into a steep, accelerating climb, Conway added — particularly valuable in combat zones to get out of range in a hurry from any hostile fighters. And he said the SB>1 promises stable and expansive fields of vision to give pilots the ability and willingness “to get down in the field of terrain,” in his words, at high speeds.

A subsidiary of Providence, Rhode Island-based Textron, Bell Helicopter is going it alone with an update of its pioneering V-22 Osprey aircraft as its candidate for the Future Vertical Lift program, also designing a smaller drone that similarly swivels its wing-mounted rotor sets to fly like an airplane after takeoff.

Bell’s V-280 Valor prototype could begin flight testing by September, only a few months past the original goal articulated by the U.S. Army in 2014. Those tests will be key, with malfunctions and crashes plaguing the Osprey program during early flights in the 1990s and 2000s, including one in 1992 in which congressmen and DOD officials witnessed an Osprey plummeting into the Potomac River during a demonstration, killing seven people on board.

Few have a better idea of what Sikorsky and Boeing are up against then Dan Schultz, whom Lockheed Martin made president of Sikorsky after acquiring the manufacturer in November 2015. While serving in the Marine Corps, Schultz was the program manager for managing the V-22 Osprey program across military branches.

As Sikorsky and Boeing rev up for SB>1 flight tests, Sikorsky is putting its vision to the test against not only Bell but its own corporate parent. Lockheed Martin itself had an existing “skunk works” project with Pennsylvania-based Piasecki Aircraft developing “ducted fan” aircraft — think the futuristic helicopters in Avatar that angle their rotor sets to maximize maneuverability — that continues to this day with an eye on hitting on a revolutionary breakthrough that could elicit future U.S. interest.

And Bell is continuing its own research work with the FCX-001, configured like a conventional helicopter in some respects but with rear rotors embedded inside the tail boom to provide pilots with superior control, among other advances.

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