The Anti-Anti-Ice Protection

摘要

Modern deicing and anti-icing methods have proven effective when properly applied and the limitations of the fluids are observed. However, the duration of that protection can be degraded by meteorological conditions including freezing rain, ice pellets and hail, heavy snow, high wind velocity, fast-dropping air temperatures or any time when freezing precipitation with high water content is present. Some other factors that can reduce the effectiveness of deicing and anti-icing procedures range from the inclination angle and contours to surface roughness and temperature of aircraft surfaces.A team of researchers from the National Center for Atmospheric Research (NCAR) and United Airlines discovered several under-recognized conditions in which an aircraft might attempt to take off unknowingly with contaminated wings. The project was sponsored by the National Science Foundation through an interagency agreement with the FAA. Its results were reported as "Common Snowfall Conditions Associated With Aircraft Takeoff Accidents," in the January-February 2000 issue of Journal of Aircraft.In the study, the team examined five icing-related FAR Part 121 mishaps. The accidents occurred at New York LaGuardia (KLGA) on March 23,1992 (USAir Flight 405, Fokker F-28); the former Stapleton International Airport (KDEN) on Nov. 15,1987 (Continental Flight 1713, DC-9-14); Washington National (KDCA) on Jan. 13,1982 (Air Florida Flight 90, Boeing 737-222); Logan International (KBOS) on Feb. 16,1980(RedCoat Air Cargo, Flight RY103, Bristol 175 Britannia) and Newark International (KEWR) on Nov. 27,1978 (TWA Flight 505, DC-9-15).