How About Story Time

On Friday, May 1, 2020 at 1:15:18 PM UTC-5, john firth wrote:
On Saturday, April 4, 2020 at 2:40:32 PM UTC-4, wrote:
Maybe this is a good opportunity for some of us to share some stories of our experiences.
I'll go first.-

During the regional at Harris Hill in 2013 I was flying K21 with grandson Calvin Mampe, Rachel Conklin, and her sister Michelle. All 3 had flown multiple contests with me before, 2 having done so before they were old enough to solo.
Half way through the contest, my wife Dianne had a terrible fall and ended up hospitalized with some very serious injuries. All 3 of the juniors had good flights with me earlier in the contest so I told them to just keep on flying.
On Friday, Calvin and Rachel flew but decided to abandon the task part way around the course due to rain. They did not want to land out and take the ship apart in the rain. Smart!
The next day Rachel and Michelle flew together. About 4:00 I was in the ICU with Dianne when Calvin called. When I answered, he simply said “K21 four miles�. Our 2 young ladies had flown the course for a reasonable score. To my knowledge, this is the first time two young sisters had ever flown in competition. We had a seriously great group hug that night. This may be my best ever moment as a supporter of youth soaring.
Following up- Michelle is now an A&P working for Textron and just finished her first restoration, a 1-26E. Rachel is instructing at Flight Safety and soon will have all the requirements for her ATP.

UH

This is often called "thermal wave" as it seems to need thermals to
get it going; it used to be a fairly frequent occurence in Eastern Canada
in the '70s and 80s.
In 1977 on a day with cloud streets at 7000 ft, I transitioned into
weak wave at cloudbase. It got better high up and I was still climbing 2kts
at 16K; the Cu had become lennies stretching as far as one could see.
I published a paper with the met. details at the 1978 Ostiv conf..

Despite regular flying in the last 20 years, I have not encountered
any thermal wave since! Climate change?

John Firth

My first flight instructor, Ed Gaddy, frequently described thermal wave. Since Ed told me about it, I have always looked for it. It is there more often than we think. I have encountered usable wave-like lift that goes above cloudbase most years and have seen it nearly every place that I have soared in the U.S. Best case was in Eastern North Carolina in 1987. I was flying an SGS-123D. Wind out of the East on the ground, brisk, maybe 15 knots. Gorgeous cloud streets forming. Textbook lenticular clouds on top of each cu. Climbed up to cloudbase at 5000'. Explored out away from the upwind edge of the cloud, about 90 degrees to the wind direction below cloudbase, and found weak, smooth lift, flew back and forth climbing slowly, lift gradually increased to a whole 2 knots. Eventually made it to 8000' several hundred feet below the leading edge of the lennies. Was able to fly along the top of the streets for miles. A couple seasons ago, at a GTA event, I was able to climb my H301 about 1000' above cloudbase. Two towering cu's merged at their bottoms and tops to form one big cloud with a tunnel through it. Flew through that mile long tunnel in zero sink. That was fun, but exceedingly weird.. Kinda like a surfer in the tube.

On Friday, May 1, 2020 at 2:15:18 PM UTC-4, john firth wrote:
This is often called "thermal wave"...

https://www.ssa.org/Contests?show=blog&id=4169

On Friday, May 1, 2020 at 11:52:26 AM UTC-7, Dave Nadler wrote:
On Friday, May 1, 2020 at 2:15:18 PM UTC-4, john firth wrote:
This is often called "thermal wave"...

https://www.ssa.org/Contests?show=blog&id=4169

Thank you, Dave, for that write-up.

On the Canadian prairies, the clue to thermal wave is a shift in cloud orientation. Takes a bit of wind, so typically a day with well defined streets up and down the wind. Abruptly, over a period of only half an hour or so, the skyscape changes - perhaps all of it, perhaps only one large area - to bands of cloud across the wind. Time to go wave hunting! Pressing forward into wind at cloud base, as others have said.

Sometimes, rather dramatic lennies cap the cu, but not always, and not the first clue.

Cheers, Bruce

I have seen lennies over tcu and cb countless times - but never any indication of secondary, tertiary wave action. Only reason I'm not calling it "wave"...

On Friday, May 1, 2020 at 7:20:50 PM UTC-4, wrote:
I have seen lennies over tcu and cb countless times - but never any
indication of secondary, tertiary wave action.
Only reason I'm not calling it "wave"...

Often there's a blue wave in back of a cu that pushes into a
higher wind-speed at top of inversion. Decades ago Ingo Renner
taught me to look for that, as the cap cloud on the cu shows
essentially ridge lift, but the rebound (wave) can go much higher.
So while you can get above the cloud in front of it,
you can get much higher downwind.

Hope I explained that OK,
Best Regards, Dave

On Friday, May 1, 2020 at 7:26:49 AM UTC-7, Nick Kennedy wrote:
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.

Anyone who has driven on washboard dirt roads has experienced shear wave. The car tires moving in a different direction from the stationary dirt road.. That makes the washboard bumps in the road. Not that I understand it. I also saw this in a wave tank with salt and fresh water as a the the lighter water passed over the lower heavier water. *Don Altman, SIO grad student, Hydro Lab, 1983. Wonder where he is today.)
Steve

Way back about 1980 I was approached by my glider friend, Chris Lomax, asking if I could help him retrieve a Libelle piloted by Joe Robertson. Seems he landed out about 10 miles from Ephrata in a dirt field. Well, since he did not have a car with a tow hook could I use my car to retrieve him? I said show me his trailer and we will be there in no time. We located the trailer (one of those homebuilt boxy aluminum types) and proceeded at near light speed toward the west. We took a couple of wrong turns on dirt roads which were dead ends, but no worry, I just backed the trailer into the sage brush and dirt and continued on the way. Soon we spotted Joe standing next to the road and we pulled up with smiles on our proud faces having made it in record time. Only problem was it wasn't Joe's trailer AND it was occupied with another Libelle. This story was kept hush, hush for awhile as the owner of the other Libelle was a very picky pilot who always kept everything he owned very clean. We spent considerable time later cleaning his trailer to a nice shine. Never
heard him complaining about dust and dirt inside so it must have been sealed well. Lynn Wyman

Thanks to all those who threw in there 2 cents about Shear Waves.

I've experienced almost all the described different Thermal, thermal induced waves etc. Cu induced waves..
But these are NOT the Shear waves that develop in Marfa Tx.

The Marfa Shear Waves are localized areas that develop, that move about 1/2 the wind speed and can go pretty High, up into the mid and high 20's. And very slow climbs, like often 1-2 knots, took hours to get high.
I was hoping a couple of Texas Pilots who understand these things were going to chime in with some sort of real explanation.

At one of these meets, I spoke with Jim Crisp, RIP, during a party at his motorhome. I remember asking him about these Shear waves; he would just smile and say
"Who knows? Aren't they wonderful? Let me get you another drink!"

Are you referring to the dry convergence, Marfa and Elsinore are known for it. Could also trigger the wave-like lift above.

On Fri, 1 May 2020 11:15:16 -0700 (PDT), john firth
wrote:

text deleted on shear waves

Despite regular flying in the last 20 years, I have not encountered
any thermal wave since! Climate change?

John Firth

I think shear waves are just a prevalent as always, but we are flying
different ships than we were 40-50 years ago.

Here in N Texas in the 70's I could climb in shear waves in my Ka6E
probably 8-10 times per year. Later in my PIK-20, maybe only once or
twice a year could I find them.

Now in a Ventus cT I find them only once every few years. Higher wing
loading makes find the small initial surges more difficult to detect.

My experience has always been max alt about 500-1000 ft over the
cumulus tops.