Lift Fan Installed in X-35B Following Successful Tests of JSF STOVL Propulsion System
Ken Garlington
Lockheed Martin Press Release
January 11, 2000
FORT WORTH, Texas – The Lockheed Martin Joint Strike Fighter (JSF) team
successfully installed the shaft-driven lift fan in the JSF X-35B in less
than three hours, as the short-takeoff/vertical-landing (STOVL) aircraft
prepares for hover-pit testing next month.
"The installation was a spectacular success. The lift fan went in very
easily," said Scott Winship, STOVL product manager for the team. "A
laser-alignment check verified that the fit is essentially perfect."
The lift fan installation includes the fan, a vectored nozzle, clutch and
all actuation and service systems in an integrated unit. Hover-pit testing
of the X-35B will begin next month at Lockheed Martin’s Palmdale, Calif.,
facility.
"Our propulsion team has recently run the fan for hours and hours on end, at
very high power settings, without incident," said Tom Burbage, executive
vice president and general manager of the Lockheed Martin JSF program. "The
lift-fan concept has always held clear advantages for an aircraft of the JSF
’s dimensions. Now we’re showing that the hardware itself is ready and
reliable."
The unique lift-fan propulsion system – a patented Lockheed Martin design –
differs from traditional direct-lift systems, such as those used in the
Harrier. Where direct-lift systems channel hot engine gases to achieve
vertical flight, the Lockheed Martin system uses a counter-rotating
lift-fan – located behind the cockpit and connected to the engine via a
drive shaft – as a primary lifting force. The fan produces more than 18,000
pounds of cool thrust in hover flight, with an additional 18,000 pounds
coming from the main engine’s vectored aft nozzle and wing roll-posts.
Because the lift fan amplifies engine power, vertical lift is achieved at
lower power settings, reducing rear exhaust temperatures and velocities and
significantly improving the ground environment.
Rick Rezabek, X-35 product manager, said the fan’s precise fit required no
adjustments after the installation, a remarkable achievement considering the
airframe had undergone rigorous flight testing (as the X-35A) and sustained
high-g loads from Oct. 24 to Nov. 22, 2000.
"We were confident that our design, tooling and assembly work would validate
our approach, and the actual installation has done that in spades," Rezabek
said. "When you consider that this aircraft has been flown for a month in an
aggressive flight test program, it is even more impressive."
The X-35B is designed to meet U.S. Marine Corps/Royal Navy-Royal Air Force
specifications. The X-35A Air Force variant was renamed the X-35B as
installation of the STOVL propulsion system began. In the Lockheed Martin
JSF design, the Air Force and Marine Corps/Royal Navy-Royal Air Force
variant share the same outer mold lines.
Lockheed Martin, in partnership with Northrop Grumman and BAE SYSTEMS, is in
competition to build the JSF for the United States and United Kingdom.
Government selection of a single contractor for the Engineering and
Manufacturing Development phase is set for 2001.
CONTACT: John Kent
(817) 763-3980
(817) 454-0279
e-mail: john....@lmco.com