Sunday, September 11, 2005

Thermal soaring at Tehachapi

The club took a field trip to Tehachapi over the holiday weekend, bringing along the PW5 and the Grob 103. I've flown there before with other pilots in a Blanik, and this time I was looking forward to flying solo over the mountains or maybe flying cross-country with another pilot. It didn't quite work out that way but I had a good time and learned quite a bit.

The winds were not favorable much of the weekend, south or north at 10-15 kt much of the time. At Tehachapi, a south or north wind (a) makes for crosswind landings, (b) blows out the thermals, and (c) does not favor shear line formation.

So I didn't fly Sat. - hardly anyone did. Sun. was better, so I did what I thought would be a checkout flight over the mountains with an instructor. (I have my cert, but club rules require an instructor checkout for new environments in club ships.) It turned out that the lift wasn't working over the mountains so we thermaled over the valley for about an hour. We spent quite a bit of time working on getting the most out of the best side of a thermal, and tighter control of speed and bank angle. We had up to 5 ships at a time in the same thermal, and unlike other gaggles I've been in, we were often at nearly the same altitude. So I got some good practice at spacing and speed control and lookout.

My landing was good but my rollout was terrible. Unlike Hemet, where we land in 800x300 feet of dirt, Mountain Valley Airport has two asphalt runways, one for power and one for gliders. I don't know how long the glider runway is - maybe 3000', but only about 8 feet wide! Think about that - an 8' wide runway to land a 50' wide aircraft! Last year I had landed there 3 times, and I think some of them were on the wider power runway, and in the Blanik, which has a swiveling tailwheel. The Grob has fixed wheels, so steering is harder. I was all over the place and, sincer there were gliders staged in the center of the runway for takeoff, I was concerned about running into them, so I braked too much and stopped way short. So... It wasn't unsafe, but it certainly wasn't pretty! After that, I knew I'd need some more flights with CFI before I'd get signed off to fly the Grob solo here. The wind came up again, so no one flew very late into the afternoon.

Monday morning was pretty calm. Several of us did pattern flights. I did two, and both were good landings and good rollouts, much straighter and rolled nicely back to the starting line, stopping perfectly level! So CFI signed me off for solo. Unfortunately the lift got a late start, and the crosswind returned - not strong, but definitely cross. A couple of us were going to fly again but with the late start and marginal lift and knowing we had to tear down both gliders and drive home, we gave up and stayed on the ground.

1 comment:

Anonymous said...

High desert sites like Tehachapi or Cal City are pretty unreliable that late in the season. That's one of the reason the Region 12 regionals, traditionally held at Cal City over Labor day weekend, tend to be so sparsely attended. Conditions that weekend were much better to the south.