Sikorsky Aircraft is
unveiling plans to build and test a demonstrator for a new class of
coaxial X2 Technology helicopters that maintain or improve on all
the vertical flight capabilities of rotorcraft and whose high speed
configuration will cruise at 250 knots.
The X2 demonstrator will feature a coaxial design (two rotors on
the same axis) and a 'pusher prop' to supply auxiliary propulsion
that will enable the aircraft to reach high speeds of 250 knots per
hour.
Sikorsky plans to build and fly its X2 Technology demonstrator
helicopter at its Schweizer Aircraft subsidiary by the end of 2006.
Preliminary design work for the demonstrator is finished and parts
fabrication for the aircraft has commenced.
X2 Technology refers to a suite of technologies Sikorsky will
apply to achieve new levels of speed and performance in coaxial
helicopters. Coaxial helicopters feature two counter-rotating
rotors on the same vertical axis.
The announcement came at the American Helicopter Society
International's annual technical forum in Grapevine, Texas, where
Sikorsky unveiled new scale models of X2 Technology helicopter
concepts in various weight classes and configurations.
"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 Sikorsky President Stephen Finger.
"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."
X2 Technology aircraft will hover, land vertically, maneuver at
low speeds, and transition seamlessly from hover to forward flight
like a helicopter. In a high speed configuration, one or more
'pusher props' are part of an integrated auxiliary propulsion
system to enable high speed with no need to physically reconfigure
the aircraft in flight.
The top cruise speed of helicopters in service today, roughly
150 to 170 knots, are only incrementally better than what they were
decades ago due to the fundamental limits of conventional rotor
systems.
Previous attempts to develop faster helicopters have resulted in
degraded hover performance. Likewise, attempts at fixed wing or
hybrid vertical lift aircraft have resulted in aircraft with less
hover capability than helicopters.
Sikorsky selected the term X2 Technology in order to: describe a
class of helicopters with a coaxial design and to describe the
multiplying effects (2X, or times 2) of applying a suite of modern
technologies to coaxial helicopters. These technologies include new
rotor blade designs, advanced flight control laws, transmissions
with greater horsepower to weight performance and the ability to
seamlessly transfer power from the main rotor to the aft propulser,
and active vibration control.
Sikorsky will also incorporate decades of company research and
development into X2 Technology helicopters, including: the XH-59A
Advancing Blade Concept Demonstrator which showed high speed was
possible with a coaxial helicopter and auxiliary propulsion, the
Cypher UAV which expanded company knowledge of the unique aspects
of flight control laws in a fly by wire aircraft that employed
coaxial rotors and the RAH-66 COMANCHE, which developed expertise
in composite rotors and advanced transmission design.