Thursday, January 29, 2009

Deicing... nah!

The next few pictures on my memory card are of my airplane sitting on the ramp in a snow storm at night, engines filling up with snow. The snow is coming down so hard that the deicing is not doing any good. But as I sit in here in FL, reading how my home in OH got 10 inches of snow in the last 24 hours, I figure there will be enough talk of snow for all of us today. I'm heading north later today anyway so I'll have be in the middle of it again very soon.

So I am going to skip ahead to some other pictures of FL. Do you recognize this FBO? We are spending a lot of time down here in FL, which I enjoy for about two months out of the year. It's too hot and humid for my taste the rest of the time. I certainly appreciated the temps yesterday when I was able to go run around the nearby lake. Unfortunately, I went in the middle of the day, and am not used to the heat. I was glad to get back to the hotel without any damage.

I do a lot of running on the road to try to stay in shape. Two great websites I have found are http://www.mapmyrun.com/ and http://www.usatf.org/routes/ They both require a little bit of work, but it's usually more reliable than asking at the front desk of the hotel about where to run. Some hotels have preprinted maps, or someone who knows something about the area (take note, hotels! we guests love this). A lot of clerks just look at you strangely, or recommend the 1/4 mi walking trail around the parking lot! I once called up the front desk to ask where I could run around the hotel, and the clerk's response was, "I wouldn't run around here." I asked if it was unsafe (it was about 5am). And he said, "No, but I wouldn't run around here." Well, I wasn't asking if he wanted to run, now was I? But I digress.

So instead of talking about removing frost, ice or snow, I'll talk about removing condensation. There are no windshield wipers on this airplane, so if we get to the airplane in the morning and it looks like this, we take cups of water out of the heated drink canisters and throw them up at the windows! If it builds back up again after we get strapped in, we can turn on the windshield heat or try to blow hot air up with the defrosters, but we definitely don't want to start taxiing without a clear view, much less take off like this guy in a NTSB report.

In trying to find a scientific explanation I found this great website, The Water Cycle. So I'll just quickly say that this condensation is a result of the windows cooling off during the night, and as the temperature rises with the new humid day, the moisture collects on the window. But here's what's really interesting:

According to columnist Cecil Adams, "a modest-size cloud, one kilometer in diameter and 100 meters thick, has a mass equivalent to one B-747 jumbo jet." ("Can a cloud weigh as much as a 747?", http://www.straightdope.com/classics/a980313a.html (another interesting site), accessed on Sep. 11, 2003). But, with all that mass being spread over such a large volume of space, the density, or weight (mass) for any chosen volume, is very small. If you compressed that cloud into a trash bag, well, in that case, you would not want to be standing below it. Even though a cloud weighs tons, it doesn't fall on you because the rising air responsible for its formation keeps the cloud floating in the air. The air below the cloud is denser than the cloud, thus the cloud floats on top of the denser air nearer the land surface.

1 comment:

  1. WOW, I love it! You have to through hot cups of water onto your windscreen :) Honestly though, I never thought about condensation on the front window... Well if your ever up in Great Falls, MT at the FBO that I work out(Holman Aviation), I think I can manage to get you some hot water from inside of the building so you don't have to waste yours :) Fly safe

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