Indicators of the Failure of Deicing and/or Anti-Icing Processes


When these processes begin to fail or loose their effectiveness the existing fluids become dull, loosing their shine or gloss. Seeing rivets, painted areas or wing seams through the fluid may become blurry and/or start to disappear is when the fluid begins to fail. This may be followed by frozen contamination formation or build up. Each fluid has a published chart of the expected Holdover Time (HOT). These HOT charts are revised and new HOT information is distributed by the FAA each fall. These HOT times are the estimated times that the fluids are normally effective during the listed possible active precipitation(s). These times are only for a ground- use guide.


Aircraft Inspection Procedures


The aircraft contamination inspections can consist of two industry-standard checks. The Pre-Takeoff Check is a check of the aircraft representative surfaces (these surfaces should be designated by the aircraft manufacturer). The FAA recommended primary representative surface is the leading edge of the wing. This check can be done from inside the aircraft. The Pre-Takeoff Contamination Check is usually done from outside of the aircraft. It should include the aircraft manufacturer’s designated critical surfaces being free of adhering contamination. These critical surfaces could be designated in the certificate holder’s aircraft surface contamination plan. This check should be done within 5 minutes of beginning the takeoff. Consider this check if you have exceeded your charted HOT time.


Trust your fingers. Trusting solely visual perception and neglecting tactile perceptions is a dangerous business when it comes to detecting aircraft surface contamination.


As you learned to feel your aircraft by the seat of the pants, learn to sense surface contamination by the tip of your finger.


10 Surface Contamination


Surface Contamination 10


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