Winds
Note: I’ve just heard about the Colgan crash in Buffalo. My heart goes out to those affected. It’s too soon to speculate as to causes so I won’t. But I feel the loss for all those involved.
Well, the last two lessons were affected by mechanical problems: the starter and turn coordinator. This one is affected by weather. I’d been watching the weather as a front was coming through. The thing I’m concerned about for are the winds at the lesson time.
I had studied the weather online, and talked carefully with the Flight Service Station (FSS - the pilot briefing people). The winds were pretty high - 17 knots gusting to 21 - but were quite close to the runway heading. So the crosswind component of that was small. The winds were 20 degrees off the runway heading so 17 * sin(20) or about 6 knots was the crosswind. Not bad at all. I can and have handled crosswinds up to 15 knots. The maximum demonstrated crosswind for my plane is 20 knots and I would feel confident with that too.
(Knots are used in aviation and marine environments for a number of reasons, mostly navigationally related. But that’s another subject. To get regular MPH from kts is “N kts * 1.15 = M mph”.)
Of course the crosswind for takeoff and landing is not the only wind effect. The higher you go the stronger the winds are, especially in the first 6000 feet of altitude. The more winds, the more turbulence as the winds tumble over the hills or simply don’t flow smoothly. This increase with altitude is from friction when the wind interacts with the trees and buildings on the surface. (Way up higher it is more pronounced, but I can only fly up to around 10-12 thousand feet. So the jet stream doesn’t affect me.)
This wind, both current and forecast, was within a range that - my experience showed - wouldn’t have turbulence that was too much. I wasn’t really concerned about comfort as it was just me and my instructor. As instructor R said later, “Above some windspeed you’re not learning anything since you’re spending all your time controlling the plane.”
So I get to the airport and make one last check on the forecast winds; they’re now “20G235″ or 20 knots gusting to 25 knots. And the direction changed too. Now they’re 30 degrees from the runway heading for a crosswind of 10 knots gusting to 18. (20 * sin(30), and 35 * sin(30))
So, I walked into the flight school office, found R, and told him we were canceling for the day. Then I went out and put additional tiedowns on my plane as the forecast for tomorrow has gusts up to 55 knots. While I may not be able to control the weather, I can certainly control how I deal with it!