For Release: Dec. 22, 1998
Keith Henry
Langley Research Center
(757) 864-6120/24
Dave George
Boundary Layer Research, Inc.
Everett, Washington
Ph: (425) 353 6591
RELEASE NO. 98-097
NASA Licenses Technology for Improving Helicopter
Performance
NASA has licensed technology to a Washington state company for
improving the performance, stability and control of
helicopters.
Under the agreement, Boundary Layer Research, Inc., Everett,
Wash., will commercially market an aerodynamic device called
"tailboom strakes." The license will allow the company to market
the NASA-patented device to civil and military operators of single
rotor helicopters.
For the past year Boundary Layer Research has been working with
NASA Langley Research Center, Hampton, Va., to explore the
viability of helicopter strake technology developed by a NASA-Army
team of researchers. The technology is applicable to all single
rotor helicopters and is patented by NASA as a "Low Speed
Anti-Torque System."
The company has applied for Federal Aviation Administration
certification to make the technology available to civil operators
and owners.
"It's always exciting and gratifying to see one of our ideas
embraced by a vigorous, young company," said Henry Kelley, an Army
researcher working in NASA Langley's Research and Technology Group
and lead researcher on the project.
The upper and lower tailboom strakes run the entire length of
the tailboom on the port side only. The strakes are typically 10 to
15 feet long and extend diagonally from the surface about three
inches, one near the top of the tailboom and one near the bottom of
the tailboom. At slow airspeeds, these narrow surfaces provide
resistance to the air coming down from the main, overhead, rotor to
create a high-pressure area on the port side of the tailboom. This
significantly counteracts a single-rotor helicopter's natural
tendency to turn due to torque, improving the pilot's control over
the helicopter.
Benefits are reported as improved stability, less horsepower
needed for the tail rotor, improved yaw (side-to-side) control,
improved altitude performance, increased payload capability at
altitude, reduced fatigue for tailboom and related flight critical
components, and reduced maintenance costs.
Boundary Layer Research president Robert Desroche said, "We are
very pleased to be selected by NASA to further develop this
technology and are anxious to get it to the operators where it can
do some good. Operators work a very delicate profit margin and this
technology will help tip the scale in their favor since it can
reduce maintenance costs and increase performance. The fact that it
improves safety by improving yaw control margins is just icing on
the cake."
Last month the company shipped a set of helicopter strakes to
the U.S. Army Flight Test Evaluation Center at Ft. Rucker, Ala. The
strakes will be evaluated for the Army’s fleet of single rotor
helicopters. In the past few months the Royal New Zealand Air Force
and the Australian Defence Force have each outfitted UH-1H
helicopters with strakes after learning of the technology from Army
researchers at NASA and conducting their own evaluations with close
collaboration with NASA.
The device represents the company’s first venture into the
rotorcraft modification market. Recently the company announced a
reorganization and the hiring of key staff to facilitate the
anticipated growth of the new Rotary Wing Division.
Boundary Layer Research designs and develops products that
enhance performance of personal and business aircraft.
Modifications include vortex generators, winglets, wing tanks,
airframe strakes, stall strips and landing gear upgrades. These and
other products have been applied to more than 60 models of
airplanes since the company was founded in 1990.
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