Tuesday, November 6, 2012

Winter discontent

The last leg back to Stockholm is what I have left. According to the TAFs, cloud cover will break up sufficiently along the whole route around midday today. The ceilings are on the lowish side, but nothing more than SCT, and dissolving into FEW as the afternoon wears on (before rains associated with the next warm front arrive from the West).

So all looks good, really, but for one thing: Winter has come, and with it comes icing. The Swedish weather service is predicting light to moderate icing along much of the route between 1000 and 4000 feet. Up around Stockholm, the TAFs say the cover should break up to SCT or FEW by noon. And the region around Stockholm does NOT have icing in the forecast.

So my strategy is to:

1) wait a little while to let that warming action happen;
2) fly at F75 or so, above the icing; the sky will be clear above the SCT;
3) pick my way back down to surface when I arrive, which should not be a problem with only SCT to deal with. Half the sky is open to fly in, even if icing were to be a risk in the clouds.

/Brian

Update 1835 LT - Well that worked, too. The plan was great until I got as far as Norrköping AD. I had asked for and gotten clearance to FL75 immediately after getting out from under Hamburg's C airspace. I was a good 1500 feet, at least, above the FEW and SCT in clear, smooth air. That lasted until Växjö, where it looked to me that the clouds were starting to consolidate into SCT. I had been listening to the VOLMET and Arlanda, Bromma and Skavsta all were reporting BKN at 900 to 1100 ft, so I knew that I would have to get down under that while there were still gaps in the clouds. As I neared Växjö I asked Kronoberg how their ceilings looked; they reported SCT020. So I got cleared down to 1600 or below by Kronoberg TWR. That was of course more turbulent, but it's always nice to be down where you can see things.

My first clue that things were going to get close came when I asked Norrköping for transit at 1400ft through their control zone. The response was, "I''m sorry, but we're special VFR, so I can't allow you transit." That meant I had to sail around them to the West. Not such a big deal, but it also meant their ceiling was below 1500ft. As I rounded Norrköpings CTL, the clouds started descending. I was getting pushed down toward terrain. The G1000 was giving me terrain alerts and warnings; I was scanning the sky ahead and the MFD for masts. Eventually, just 10 minutes or so from Eskilstuna (who told me when I called them that their ceilings were "OK", so I knew I could land there) I finally had to pop up through the clouds instead. I couldn't go down any more, safely. To give you an idea, I only had to go up to 1800 ft to get "on top"!

A little dramatic because I really take seriously not flying in cloud, but there was no choice. I just focused on the panel, kept it level and watched my climb pitch and air speed. After just a couple of minutes I saw Eskilstuna AD and took a completely normal right base approach and put it down. After re-fueling, the hop over to my own field was undramatic, as by that time the cloud cover had dissipated almost entirely.

2 comments:

  1. -why was it 1600 "of course more turbulent".
    -holy sh*t you flew up through a layer.
    -did you know when you went up that they would end before you came to your airport. they said 'OK' so you knew they meant, higher than 1500'?

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  2. @Mr. R - Below the clouds is always more turbulent. Perhaps the ground action (warming or cooling) is more active down lower, and the clouds form a stop layer, so the circulation is from the ground up to the clouds and back.

    - Yes, I didn't plan the trip to be in clouds, and all the TAFs said I had the required ceilings, but when you are in the air, and things change, you have to adjust. Better to fly up through the cloud layer than to let it push you down to the ground. But you have to be aware that you are going from visual to instrument flying. You have to be aware that you no longer have a horizon.

    - Yes, since the AD TWR told me they had clear skies, I knew that I would be able to get back down without going through clouds. I interpreted "OK" to mean, CAVOK. Going down through clouds is a lot worse than going up through them.

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