Nearly
three years ago, Sikorsky Aircraft announced it would develop technologies — collectively
called "X2 Technology" —
that would significantly change helicopter flight. Every day thousands of
people in the United States travel
in helicopters, among them politicians, executives, tourists and patients.
The main
advantage of helicopters
— categorized as rotary-wing aircraft — is their ability to take off and land vertically.
However, compared with fixed-wing aircraft, they are slow. For example, the
12-passenger S-76 helicopter flies at 178 mph, but an 11-seat Beechcraft
KingAir 350 turboprop flies at 350 mph, nearly twice as fast.
However, United
Technologies Corp. subsidiary Sikorsky Aircraft, the oldest name in helicopter
manufacturing, is working to change that by developing a helicopter that will
fly almost as fast as a conventional aircraft — without using the mechanically
complex and expensive tilt-rotor
system pioneered by Bell.
Sikorsky
plans a faster helicopter
On June 6,
2005, Sikorsky announced that it would build and test a technology demonstrator
that would maneuver like a conventional helicopter and cruise at 250 knots (288
mph), which is at least 60 percent faster than conventional helicopters.
X2
Technology helicopters will affect passenger travel due to substantially
reduced flight times. For example, flights between Bridgeport, Conn. and JFK Airport in New York City would be decreased from 40 minutes to 25 minutes.
Also, X2 Technology medevac
helicopters would be able to transport people in critical condition to
hospitals in significantly less time, potentially saving lives.
"We
initiated X2 Technology convinced that the most productive and flexible
helicopter is a helicopter which is capable of a significant increase in speed,"
said Stephen Finger, then-president of Sikorsky Aircraft. "Customers are
demanding greater speed but without sacrificing any of the unique capabilities
that make helicopters the
ideal platform for countless civil and military missions."
Advanced
aerospace technologies
Although the
top speed of helicopters has not increased much since the 1960s, improvements
in computers, materials, navigation systems, and other aspects of aircraft
during the past two generations have been unprecedented.
Sikorsky's
X2 Technology Demonstrator incorporates leading-edge aerospace technologies,
including digital fly-by-wire flight controls, counter-rotating rigid rotor
blades that spin more slowly as the helicopter reaches higher cruising speeds,
active vibration control, an integrated auxiliary propulsion system, and more.
X2
Technology aircraft will take-off and land vertically, hover, maneuver at low
speeds, and transition from hover to forward flight like regular helicopters. However,
the new Sikorsky aircraft will have one or more aft-mounted 'pusher' propellers,
a significant difference in design from helicopters of the past six decades.
Coaxial,
counter-rotating blades
Most
helicopters have a 'disc' of rotating blades on top of the fuselage and shorter
blades mounted on the side of the tail that spin in a plane roughly
perpendicular to the main disc. The purpose of the aft blades is to provide a
counterforce to the torque effect on the fuselage created by the spinning main
disc. The X2 Technology Demonstrator has a coaxial rotor system comprised of
two hubs with blades attached. The hubs spin in opposite directions, which
eliminates the torque effect.
"The X2
Technology Demonstrator is an integrated suite of technologies intended to
advance the state-of-the-art, counter-rotating coaxial rotor helicopter. As we
continue to work to prove and mature the technologies that will allow the X2
Technology Demonstrator to become a viable product, we are focused on testing
its limits and finding out where this technology will take us," Jeffrey
Pino, Sikorsky's president, said recently.
"This could
be a 'game changer' in the industry," Pino said of the X2 Technology
Demonstrator at Heli-Expo 2008, the main U.S. helicopter convention. "We
are diligently pursuing this as a research project. We are testing the limits
and pioneering this exciting innovation."
Sikorsky
built the X2 Technology Demonstrator in collaboration with subsidiary Schweizer
Aircraft, and funded the project entirely by itself. The aircraft continues to
make progress toward its first flight, said Peter Grant, Sikorsky's senior manager
of Advanced Programs.
"Throughout
2007, the aircraft made excellent additional build and subsystem test progress,
re-entering vehicle ground testing in November 2007," said Grant. "Extensive
test instrumentation is also being installed as preparation for its first
flight."
No
first-flight date yet
Ground
testing of the X2 Technology Demonstrator is still underway and Sikorsky hasn't
yet scheduled a date for the aircraft's first flight, said company spokesman
Paul Jackson.
"Experimental
aircraft have minds of their own — sometimes you have to let them proceed at
their own pace," said Jackson. "For that reason, we have not targeted
any date for the first flight."
Sikorsky
Aircraft, has been consulting with helicopter operators to determine how X2
Technology aircraft would benefit their business at a price they can afford. Sikorsky
is developing plans to design and build a civilian X2 Technology helicopter
that would satisfy operators' requirements and appeal to the traveling public.
"Certainly
civilian travel appears to be a promising market. People will be able to fly
back and forth from visits, dates, and meetings twice as fast each way as it
now takes by helicopter," said Jackson. "Perhaps a helicopter air
taxi market will evolve as many aviation experts have predicted for the
small-airplane segment."
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