saw this, made me think of recent accidents

[Lauren Tjaden]

Hi,
I saw this '94 article by Larry Tudor in the Oz Report, and it made me think of a couple of recent incidents in the CHGPA. Also, someone reported in this forum that once in the past he had been slammed in from above. I dunno, but I thought it was interesting.
Lauren

The Gradient Rotor
By Larry Tudor

Most pilots mistakenly assume that the only danger involved in landing in strong wind is the wind gradient, but there is another hazard that can imprint your face on the proximate terrain. It is known to sailplane pilots as “gradient rotor”.

My first introduction to gradient rotor was during the last round of the X-C Classic in the Owen’s Valley. After being flushed off the White Mountains in a strong north wind I set up for a conservative approach in the valley, well away from the mountains. I hovered down, and just as I was lowering my legs the glider got slammed from above and I free fell the last 15 feet. As I was sitting there contemplating my sore feet and bent basetube Jeff Burnett had a perfect landing 100 feet in front of me.

Several years later I was sitting in a restaurant outside Lubbock, Texas and I realized what happened. Outside the wind blew strong across the cotton fields picking up dust. Occasionally the dust would form a ball and roll across the field like a tumble weed. The wind was causing a vortex produced by the shear between the gradient and the stronger wind above.

It was obvious that if someone were landing just at the downward edge of the rotor he would be slammed down or at least drop a wing. No amount of extra airspeed could make up for the down air.

The important thing to realize is that this turbulence can exist over flat ground with no obstructions upwind!

I’m not sure what precautions someone can take when flying in strong winds to guarantee safe landings. Certainly, have your feet under you and anticipate being slammed. Perhaps pilots need to assume this risk if they are going to fly when the winds are strong.

Hang Gliding January 1994

[hepcat1989]

Hmmm. Some food for thought.
Thanks Lauren.
Peace, Shawn.

[Ashley Groves]

I have heard stories (rarely, but happens) in the Reno desserts. The stories pretty much vary on plummetting to the ground then flare before impact. Seems that there is a combination of bad luck in getting in one, good luck on getting out without bodily/ equipment damage.

Not sure if that helps anyone.

[brianvh]

read the Hyner report for more accident reminder issues. (Not to me, and nobody was injured, thankfully).

[RedBaron]

Great discussion Lauren!
Exactly what happened to me at Woodstock and later again but that time with no damage to the glider at High Rock. Not sure about a wide open flat field, but I'd certainly characterize all our house LZ's with all those high trees running around as very technical and dangerous. Even speed won't always safe you on a low end glider. And landing a high end glider with lots of speed will most definitely carry you way beyond the confines of the Woodstock LZ for example, unless you want to make that last fast turn below the tree line close to the ground and through the potential rotor zone.
I learned two essential things this season. 1) Wheels will safe your bones. 2) Flying later in the day will safe your glider. It's actually very simple.