Obligatory Frost Reminder

October 14, 2009 by Bruce Landsberg

FrostOne of the great benefits of flying is that it keeps us close to nature. In the summer it’s thunderstorms and high density altitude. In the winter it’s winds, snow, ice and frost. This is a brief reminder of something we all learned in ground school. Frost or otherwise contaminated wings do not work well and can be quite unpredictable.

Over the past decade there have been several high profile accidents involving corporate jets that didn’t have the juice to get airborne because of wing contamination. “Looks OK to me” is not a substitute for really checking wing and tail surfaces. Frost is deceptive because it’s so thin but it messes up the boundary layer flow – badly.

When I fly in frost season and can’t get into a hangar, a can of automotive windshield deicer spray works very well. It’s about $3 a can and I can usually get two defrostings . Do NOT spray on your windows – just wings and tails surfaces.

A short story – I had forgotten my deicer and had to rely on the FBO at a big airport. They tugged out a machine the size of a small boxcar, fired the beastie up and then we waited 15 minutes while it belched, barfed, shook and smoked to heat up the very expensive deicing fluid inside.

The line person blasted away with a nozzle designed for Boeings until the little Piper I was flying was literally dripping with goop. I mentioned that it was probably sufficient and just for curiousity asked how much the goop cost per gallon. Let’s just say that I could have bought enough deicer to last me for a decade.

That said, you just have to wait for the sun or pay the price. Either way – it’s far better than an attempted frosted takeoff. That could be really expensive.

Cold-FactsCheck out ASF’s Cold Facts: Wing Contamination Safety Brief.

Who’s got a frost or wing contamination story?

Bruce Landsberg
Senior Safety Advisor, Air Safety Institute

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  • http://www.computertutorit.com Jeff Perkins

    Your comment on the cost of deicing brought back a wallet pain I experienced myself just lsat year. Being a renter pilot, the airport I use to rent from locally has always had a little garden sprayer that they use for deicing the aircraft when you don’t want to wait for the sun to do it’s work. I flew up to my parents in N. Ky and as usual landed and parked at the Lunken Field in Southern OH for the holidays last year. I planned a quick get out the morning after and when I arrived I found the frost had created an entirely new paint job. I too, did not know any better, so I asked the lady at the counter if they had deicing, she said sure, it was something a little high, but she gave me the price per gallon. I was thinking of my home FBO at Morristown Murrell and the fact that they used maybe 2 gallons max of a 3 gallon sprayer… so heck $20 to $30 didn’t seem all that much to pay to get in the air an hour or two earlier than waiting on the sunlight. HAH! I got all sweaty when they came out with the firetruck and blasted that plain…. I think the final bill was somewhere around $240 to coat my little 172 with goo! Some lessons just dont’ come cheap!