Ice and frost on the wing can be serious flying hazards. Hence, the responses to a recent question about the best method for de-icing or de-frosting a wing on the Ask a Flight Instructor website is well worth reading. The question poster had also wrote:
I’ve heard either Glycol or a little bit of rubbing alcohol can be sprayed on the wings. Then what? Just rub it off GENTLY with a towel or nylon bristle brush?
-Also, when is it appropriate to use pitot heat? When visible moisture is present?
In response, Paul Tocknell noted several aircraft icing resources that are well worth mentioning again:
- AC 91-74 Flight in Icing Conditions
- AC 135-17 Pilot Guide: Small Aircraft Ground Deicing
- AC 20-117 Hazards Following Ground Deicing and Ground Operations in Conditions Conductive to Aircraft Icing
- AC 91-51AEffect of Icing on Aircraft Control and Airplane Deice and Anti-Ice Systems
- Aircraft Icing Tutorials / Modules developed by NASA
In addition, Paul noted that you should never take off if you have frost on the wing as even a small amount can impair lift. He also noted that the best way to de-ice a wing is to warm it up in a hangar and once it starts to melt, simply wipe the wing down with a towel so that the water won’t refreeze again once you are out of the hangar.
Paul then wrote that he uses pilot heat whenever he is in any visible moisture regardless of the temperature as you never know when you might pick up icing. In fact, he wrote that he once picked up serious icing on the edge of a summer thunderstorm once and that more than a few aircraft have been lost because a pilot forgot to turn the pilot heat on.
After Paul’s response, Lance, a pilot based up in Alaska, added:
Snow, absolutely none is allowable, however frost that fits between the wing covers and the wings is typically considered flyable. The other thing you want to watch for is whether conditions aloft will allow the frost to sublimate off as you are flying, (same principle as to why if you get into icing conditions descending is not always the only solution). Also the way most pilots up here clean frost and excess snow off of their wings is a clean, soft bristle, push broom, since hangar space comes at a very high premium.
Hence and if you are planning to fly this winter, keeping the above de-icing and de-frosting tips in mind will keep you safe in the air.
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