Fighting Mother Nature's Wintertime Fury

CHECKTIME: A BETTER TOOL FOR ANTI-ICING

- Les Abend

The visual of large blue and green aluminum fragments floating in the ice-laden Potomac River as we descended on our approach into Washington National Airport is still vivid enough to remain locked in my memory. The evening prior, Air Florida Flight 90, a Boeing 737-200, had crashed into the 14th Street Bridge just after takeoff during a nasty snowstorm.

I remember the date because the ink hadn’t dried on my ATP certificate, my having passed the check ride only one day before. The dramatically documented accident occurred on January 13, 1982. Although many other significant factors contributed to the tragedy, the event became a watershed moment for the airline industry, bringing increased awareness to the dangers of airframe icing.

Most of us understand that icing deforms the surface of the wing, seriously degrading lift-producing capability. The degree to which the degradation occurs is dependent on many factors that include, but are not limited to, the type of precipitation, the intensity of the precipitation, the outside temperature and the shape of the airfoil.

Unfortunately, it wasn’t until just over 10 years after the Air Florida crash that deicing and anti-icing operations were profoundly improved. The improvement came as a result of the accident analysis of USAir Flight 405, a Fokker F28 that crashed shortly after takeoff from La Guardia’s Runway 13 during a snowstorm on March 22, 1992. What was discovered?

First, the National Transportation Safety Board determined that the Type I deicing fluid applied to the F28 on two separate occasions before taxi was not capable of continued icing protection for the conditions present beyond a few minutes. It was certainly compromised after the 35 minutes USAir Flight 405 spent on the ground. Type I fluid’s purpose is simply to rid the airplane of contaminants as a deicer, and has very limited ability as an anti-icer.