Unexpected

My weather flying is so much less scientific than in other countries. In the modern world pilots look at high and low pressure charts, consider winds aloft, check temperature and dew point spreads, and even understand what to expect as the barometer rises and falls. Me? I look outside and decide if I can see that hill. If I can, then it’s worth taking off.

Often tropical weather changes rapidly with isolated storms. Thankfully, those isolated storms are rarely embedded here in Papua. If there’s a bad storm, one to avoid, usually it’s clear for miles and miles around it.

One day I departed on a longer flight leg than normal. I was headed all the way to Sentani, an hour north and east of my home airport in Wamena. Enroute to Sentani there were several isolated storms, and I worked my way around them quite easily.

After dropping my passengers off and getting loaded back up for our return flight, I started up, got cleared for departure and left Sentani behind. I wanted to get home before things got much worse.

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This map spans nearly 3000 miles and is the best source of weather we have.

Once I was airborne, I found the weather had moved. I’d expected that, and confirmation was comforting. To get around the storms I initially headed almost due west. 40 miles later I rounded the end of the worse of the storms and found myself 12,000′ above the jungle with about a hundred miles visibility. There were a couple more smaller storms building on my route but they looked pretty insignificant compared to the huge one I’d just circumnavigated with tops only at  an estimated 18,000′ to 20,000′ or so.

I had a couple options for how to deal with the smaller storms in my path. I opted for shooting straight between them over some lower clouds connecting them. I set my course, switched on the auto-pilot and took those few minutes to do some monthly instrument checks.

A few moments later I’d finished my task and re-evaluated my situation. I was on course to slide between the two building clouds, but I realized that I’d be passing through the very tops of the clouds between them. This didn’t concern me at all. In hindsight, it really should have.

I hadn’t even entered the first cloud when the updraft began. As soon as I felt that, I knew I might be in for a ride. I killed the auto-pilot and reduced power. Seconds later it hit. As the misty swirls engulfed my plane, what felt like a huge ocean swell washed over my place rocking it’s nose up and dropping one wing. I flew on instinct. Power back. Maintain pitch attitude. Accept altitude deviations. The hits kept coming. My vision tunneled in on the instruments as the grey clouds around the plane tossed me about in my seat.

It lasted about 20-30 seconds. But even that felt too long. Out the other side of the clouds I popped, and again I had a beautiful few. Miles and miles of jungle stretched out ahead with blue sky and a few puffy white clouds along the way between me and the mountains nearly a hundred miles away.

As the plane droned on as if nothing had happened, I pondered how I could have missed the possibility of that turbulence. All the signs were there. A rapidly building cloud at 12,000′ between two known storms. Isolated storms building and moving through the area. I just hadn’t been thinking about it clearly. Perhaps I was tired. Perhaps the altitude was affecting my thinking process. Whatever it was, it was a cheap lesson for me. Don’t mess with storms. When they say in training to stay 20 miles away from a known storm, they mean it. Keep clear and arrive alive.

Have you been surprised by the weather? What events can you think of that contributed to you being surprised like that?

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