HISS Calibration, Ice Phobics and FAA R/D Evaluations
Final rept. Jan-Mar 1981
ARMY AVIATION ENGINEERING FLIGHT ACTIVITY EDWARDS AFB CA
Pagination or Media Count:
Artificial and natural icing tests of a JUH-1H helicopter were flown in the vicinity of St. Paul, Minnesota, during the three month period of January through March 1981. Productive flight time totaled 15.4 hours in the artificial icing environment behind the Helicopter Icing Spray System HISS and 3.2 hours in natural icing. Test conditions ranged from -5 degrees C to -20 degrees C and 0.25 to 1.0 gram per cubic meter gmm to the 3rd power liquid water content LWC for the artificial testing and -6 degrees C to -9 degrees C and 0.1 to 0.5 gmm to the 3rd power LWC for the natural testing. Tests in the artificial icing environment behind the HISS were flown to define the nature of the HISS cloud in terms of LWC, cloud particle size and distribution and to quantitatively determine the effects of an ice phobic coating on the capability of the UH-1H to fly in icing conditions. The ice phobic coating did not significantly affect the capability of the UH-1H to fly in icing conditions. The capability of the UH-1H to operate in icing conditions was assessed during the artificial icing flights behind the HISS and during the natural icing flights. Flight into moderate or higher intensity icing should be prohibited because of the severe vibrations experienced as a result of asymmetric ice shed. Prolonged flight over 10-15 minutes into light icing is not recommended and should only be attempted with caution and with an option to vacate the icing condition due to consequences of encountering icing of higher intensity. Data to support Federal Aviation Administration research and development requirements were obtained at every opportunity during the test program.
- Test Facilities, Equipment and Methods