Sunday, November 4, 2007

Real-time Weather Decisions

The internet is really a great tool for aviation, especially when it comes to weather forecasting and trip decisions. Although pilots are required to have a complete outline of the trip (and one of the best ways is through 1-800-WX-BRIEF), it's always a good idea to bone up on the current and forecast weather before giving the briefer a call. That way, you know ahead of time what they should be telling you and it is easier to listen to the specific details without trying to picture it in your head.

Today, I had a bit of information that, somehow, the briefer did not. Inexplicably, as I was looking at the current field weather on my computer screen, the briefer's system indicated "no information". And my source was the automated weather directly from the airport. I don't know where Lockheed-Martin gets its data, but it had better get with the program.

Not that it would have made much difference. The intended flight was a 250 mile night round trip that would have skirted right along a cold front in winds of 30 to 40 knots. The forecast was literally changing hourly, since no one could seem to get a handle on where the front would move and how fast. Rather than push the envelope, we opted for a bit shorter flight along the same route that I flew just two days ago. With it being night, this was fine with me, but I didn't have any flight plan made up for the trip. So we "winged it" as it were, and used VOR and GPS navigation to make the run.

It was still windy, but not as bad in the direction we were going -- only about 25 knots or so. So we made terrible time on the outbound leg, but definitely made it back on the return. And with some mountain waves of turbulence thrown in for good measure, it was challenging to remain on course and at altitude.

We arrived at the destination, and did some touch-and-gos. Two were on the big runway, and two on a smaller crosswind runway. The lesson was aimed at forcing me to maintain the proper glidepath (at night and without the VASI). I still come it a bit too high and with too much power, but again, I managed smooth landings. The shorter, narrower runway forces much of the sloppiness out of the approach, since if you don't have it right on, you won't have enough room.

After a few of those, we went back up for the return trip. Again, fairly uneventful, and a bit more turbulent, since we were 1000 feet lower, but manageable. The arrival at the home base was also a bit of work, since we had a pretty good crosswind. I had nearly full rudder in to compensate. As we touched down, I had to let it go and give opposite rudder as the wind went away and the controls lost effectiveness. I had a bit of a swerve, but it was still a decent landing.

Even with all that, it's only about half of the night cross-country hours that I need, so I'll hopefully have another soon. Maybe next time I'll be able to give the nearby Class C airspace a go.

As a postscript, I feel pretty good about my weather analysis, since I probably could have taken the longer trip if I had an alternate field (just in case). Simply watching the satellite pictures and observing the conditions "up stream" led me to believe that the weather was not going to be quite as bad as forecast. While I don't know what's up a few thousand feet wind-wise, I can see that the forecast overcast and rain is a total no-show. That front just wasn't going anywhere and we probably could have skirted it in both directions. But the local weather lore says that when the wind gets above a certain speed in certain places, the turbulence is terrible. That much is likely the case tonight, and while it technically would have been a reasonable VFR flight, I don't cherish bouncing around the sky like a ping-pong ball.

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