Le vendredi 1 mai 2020 16:26:49 UTC+2, Nick Kennedy a écritÂ*:
Eric
Good Morning
Like I said I went to 2 of Dick Johnson's camps at Marfa to fly the Shear Wave.
I got about 10 flights in there.
Others please chime in here as I don't really understand these waves, but here is what I know.
They Are Not classic Mt. lee Waves.
Marfa tends to be pretty breezy/ windy in the spring.
At the first pilot meeting Dick asked who had never been here before and after the usual, do this, don't do that, don't crash,pick up your trash talk he had a meeting for us newbies.
He told us to thermal up as high as we could and then instead of putting the nose down and speeding off, keep the nose up and sniff around and try to transition into the shear wave. It is a area that moves about 1/2 the wind speed and is variable from 1-3 knots up. He explained it was caused by a wind shift. Like say in Marfa the wind at 12k might be 270 @ 28, then just above the wind might be say 230 @ 35. I don't understand how but this bounce occurs in Marfa but you S Turn and 360 in this area going up to stay in it, and you can get pretty high. You slowly drift downwind while climbing. And its smooth.
Like I said I don't really understand it- even now, but its there on a regular enough basis to have camps.
Dick and his wife were great and very helpful to me at these camps!
When he saw my Ka6CR he knew it was not the highest performing ship in the fleet so he pulled out my map and marked some places to put it down NE of Marfa if I came up short, which I did one day, which is another story for Story Time.

I had a similar thing in Norther Germany (which is as flat as flat can get)..
Wind shear at a little less than cloudbase (with well developed streets) created a wave with the Cu clouds as obstacles, and I was able to climb 2000 ft above cloud base.