Wednesday, October 12, 2016

Under, Over or Through

Autumn is settling in, but company wants me to go north. The weather is actually better in the north as a ridge of high pressure is pushing in from the territories, but the south is nasty, cold and rainy. The clouds and weather pages of the graphical area forecast are all scalloped edges and green dots as a low pressure system drags itself slowly across the province, dumping snow and rain. I flip over to the icing and turbulence chart and see a vast area of blue dots centred on my airport. Moderate mixed icing, beyond my aircraft capability, from the freezing level to eighteen thousand feet. I flip back to the clouds and weather page to look at the clouds bases and hmmm over whether I could get thorough VFR underneath it. Picturing the terrain, it's iffy, and there aren't weather reporting stations or escape airports at the worst spots. The terrain isn't that high, but the cloud bases are going to be that low, and forecast low visibility under the bases makes scud running a bad proposition.

Back to the icing chart. Can I get VFR under the weather to a point where it would be safe to climb to an IFR altitude? No, I can do better. The freezing level will actually get quite high today, and while it drops as I go north, it's still high enough at the point where the icing forecast ends that I might be able to go IFR close to the minimum allowed altitude. I pull out the chart and find a not-especially-direct route that uses airways all with minimum altitudes below the ice. I won't even have to fly the wrong way, or between the MOCA and the MEA, below nav aid reception. I'll start a climb just before the end of where the ice is forecast, in order to get onto the adjoining higher airway segment. I check NOTAMs and winds, do the math to declare my ETA and file a flight plan.

I realize at the last moment that I haven't chosen an alternate. The obvious one already has low weather, and while it might technically qualify as an alternate because of its precision approach, I'd like an actual alternate that I feel confident I can get into, if my destination goes down in freezing fog. I ask the briefer to recommend one. He starts to name the same obvious one as I was going to, and then clearly has the same thought as I did, and recommends one that I never consider because has no fuel for me. I put it down anyway. I would be safe on the ground at least, and would land there with enough fuel to get back VFR to the original destination.

A few minutes after I get it all filed, the flight is cancelled. My co-worker apologizes, for making me come into work and get the plane all ready for nothing. I really don't mind. Figuring out a flight plan is a bit like solving a crossword puzzle. There doesn't have to be a point or a prize. And now I don't have to go flying in nasty weather. I go home.

2 comments:

Jared said...

Thank you for this beautiful anticlimax.

RTD8450 said...

I truly admire how you can, in a few words, take an enormously complex process and break it down to be easily understood by the brains of the non-aviator. Your description exudes the confidence of doing a vital task easily, primarily because you do it (well!) all the time. You also provide needed insight for those of us who love aircraft, flying (anywhere) and the aviation community. Many thanks, and sincere cheers from here,
RTD