As part of its Rotorcraft Program, NASA is
committed to providing the experimental data
necessary to (1) validate newly developed predictive
capabilities and (2) provide physical insight into
those areas where accurate predictive capability does
not yet exist. To make the acquisition of these data
possible for large-scale rotor systems, NASA and the
U.S. Army have developed a new wind tunnel test
stand, the Large Rotor Test Apparatus (LRTA). The
LRTA (see figure 1) is designed for testing
moderate-to-large helicopter blades and tilt rotors up to 50,000
pounds of thrust and 6,000 horsepower and provides
unique capabilities that will support both industry
and government rotorcraft test programs.
During the past year, two major milestones were
reached in the development of the LRTA. The first
was the successful calibration of the LRTA rotor
balance, following fabrication and assembly of the
LRTA rotor balance calibration facility (figure 2). This
calibration effort demonstrated the capability of the
LRTA balance design to measure rotor hub loads to
better than 0.5% full-scale. This level of load
measurement accuracy is critical to the successful wind
tunnel testing of large rotor systems.
The second milestone reached in FY99 was the
design, fabrication, and integration of a state-of-the-
art digital rotor-control console for use with the
LRTA. This new console provides the digital com-
mands and feedback controls necessary to safely "fly"
a rotor system in the wind tunnel. In addition, it
provides the capability to control the LRTA dynamic actuators,
allowing for dynamic high-frequency blade
pitch control up to 30 hertz.
With these major milestones met, the LRTA is
now ready to become the workhorse facility for
NASA's large-rotor experimental programs.
Point of Contact: T. Norman
(650) 604-6653
tnorman@mail.arc.nasa.gov
Back To Top
Previous Paper
Return to Global Civil Aviation
Next Paper 
