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By waveview
#374560
After reading a thermal flying guide * that said pilots often don't bank their gliders steep enough in 360 turns while thermaling. The article went on to say that the best indication of bank angle is the amount of time it takes to complete one 360 degree turn . Higher bank angles mean faster , tighter 360's I guess.

So is there an optimum bank angle for hang gliders while flying thermals?

* http://www.sac.ca/website/index.php/fr/ ... lling/file
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By Fred Wilson
#374562
Given adequate + extra safety speed, punch out the bar. Hard. FUN! :thumbsup:
That'll whip you around quick like, once you get the hang of it.

Plus its a useful tool to know. Thermalling skill 101 stuff.

Can scare the She It out of you the first few times though. Heads up!

Image
Last edited by Fred Wilson on Sat Aug 15, 2015 11:38 am, edited 1 time in total.
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By waveview
#374566
piano_man wrote:Depends on many factors, especially the thermals. Here's some reading that should help.
Thanks Piano Man - the advise in the link about bank it up down low and reduce bank angle as you get higher, makes sense.
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By waveview
#374567
Fred, Thanks for the pointers but always a bit suspicious about posters and captions in a language I can't read. Specially when it's of Arabic origin.
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By TjW
#374568
Fred Wilson wrote:Given adequate + extra safety speed, punch out the bar. Hard. FUN! :thumbsup:
That'll whip you around quick like, once you get the hang of it.

Can scare the She It out of you the first few times though. Heads up!

Image
"Punching out" isn't sustainable, though. It will give a brief, quick turn, (which you might need, sometimes) but it's not the same as simply flying with a little more bank angle.

I don't think there's any particular formula you can memorize as far as how steeply you need to turn, because it will vary from thermal to thermal.
But try a little more than you think you need and see how it affects your climb rate.
For myself, I'd rather find the groove that has me climbing pretty consistently all the way around than tire myself trying to punch out as I pass through the very core. Once I've got it centered, I can play with bank angle to see what works best.
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By andylongvq
#374569
Here's some video of me climbing in my Atos. You can count the duration of the circles because the footage is continuous.

3,000 Foot Climb
https://vimeo.com/67354691

Banking A Bit More Steeply (starts at 4:50 in the video)
https://vimeo.com/71696503

3,000 Foot Climb That Starts Very Slowing (starts at 8:10 in the video)
https://vimeo.com/71696503

Of course, with a flex wing you'll be able to make a smaller circle at a given bank angle than a rigid.

- Andy
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By Wonder Boy
#374573
waveview wrote:After reading a thermal flying guide * that said pilots often don't bank their gliders steep enough in 360 turns while thermaling. The article went on to say that the best indication of bank angle is the amount of time it takes to complete one 360 degree turn . Higher bank angles mean faster , tighter 360's I guess.

So is there an optimum bank angle for hang gliders while flying thermals?

* http://www.sac.ca/website/index.php/fr/ ... lling/file
There is not one single "perfect" bank angle for "all" thermals ...... **But there is for the one you are currently in at that time.

By that I mean you need to maintain the best angle / speed for the piece of lift you are in, at that time. That can change throughout a your climb.
Listen to your instrument, feel the glider and what its telling you to find that sweet spot of "the best climb rate"

So basically, make the beeper box go as fast as it can!
Whether that be a steep bank angle (narrow thermal, gotta bank it up to stay in the core) or flatter fat wide thermal.

*
If you are bored, have a listen, starts off about 5 min mark, (boring for awhile)
about the 5:50 mark starts getting better. https://youtu.be/3NtEgoTgNxM?t=5m49s
This thermal changed a lot down low, some good pieces, some narrow strong stuff, leading up to a consistent strong fairly wide climb.
The thing to watch is how my angle and speed change, while the climb rate stays close to the same in some of it.
Just a general piece to reference
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By mbadley
#374581
This discussion has been going on ever since the first glider circled in lift.

The best advice I have found is "Find the bank angle that makes the beeper go faster!"

If the lift is strong - you get more opportunity to push out and bank higher, tightening your circle and getting around faster. Try that in weak lift and you are likely to find yourself getting dumped into a spiral dive that loses far more altitude than you gained.

Flying 'slow' is also the best way to maximize ANY kind of thermal. The more time you can stay in the lift core, the better you are. I have sometimes found that with thermals that drift fast, if you push out and extend your 'into the wind' part of the circle, then pull in and crank it around quickly on the 'downwind' part you do a lot better than just setting a constant bank.

Some days I get it jussssst right. Other days, seems like nothing works. That really is the joy of flying hang gliders. Otherwise, we'd just add motors and fly it ultralight style.
By blindrodie
#374885
...if you push out and extend your 'into the wind' part of the circle, then pull in and crank it around quickly on the 'downwind' part you do a lot better than just setting a constant bank.
Those are what I call "bird words". :twisted:

That is a good description of classic bird soaring flight patterns in said conditions. Turkey vulture, hawk, eagle, pelican, sea gull... I'm a big fan of observation learning.

8)
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By Wonder Boy
#374886
waveview wrote:
Wonder Boy wrote:
There is not one single "perfect" bank angle for "all" thermals ...... **But there is for the one you are currently in at that time.
Thanks Mike, after watching your low save video flying the ATOS , I see what you mean.

[youtube]http://www.youtube.com/watch?v=uaWpBZmlq_Q[/youtube]
Excellent :thumbsup:
That was a ratty little s---!! It wasn't playing nice, but I coerced my way in it :wink:
(Had a friend on the radio giving me unwanted wind information from on top on what was happening there, when I was trying desperately to hang on to the ratty little thermal. I asked over and over to stop...... I needed all my concentration)
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By NMERider
#374889
Wonder Boy wrote:....(Had a friend on the radio giving me unwanted wind information from on top on what was happening there, when I was trying desperately to hang on to the ratty little thermal. I asked over and over to stop...... I needed all my concentration)
Radio etiquette spats have nearly resulted in fist fights in my experience. Certainly a lot of screaming back and forth in each others faces. Pilots and drivers generally try to be polite and don't say anything until they can't take it any longer and just explode at each other. I've been guilty, innocent and neutral on this issue. Pat Halfhill has had by far the best radio etiquette of any pilot I've flown with. I'd like Pat to write an article on the topic.

Getting back on topic, the tightest 360's I have ever done while climbing at a rapid rate on my T2C 144 have measured out to 60' in diameter. Interesting to note that the rotation was 7 seconds so these were fairly slow turns. This particular thermal had a segment with severe cascading around the perimeter such that if I dipped a wing tip into the edge I could feel it trying to flip my glider inverted. I was literally twirling around in the core to avoid getting flipped and having to deploy. This nastiness only lasted for two revolutions, thank goodness. My bank angle was moderate--say 45 degrees.

I have been in other cores where my bank angle needed to be around 70 degrees and airspeed was 44 -50mph just to keep control of the wing and stay in the core. Yes, I was climbing too but mostly just trying to stay with it until it smoothed out.

The spot where the Sylmar pilot got flipped and died is notorious for the kind of thermals described above and many of us now cringe when flying in this area. I cringe any place that has the kind of rolling edge thermals that flipped him. And I have unpleasant flashbacks from analyzing each from of the recovered video. I have spoken with several other pilots who have gone though the same or similar experiences. It doesn't deter me from flying but my fear of G-d sure increased.
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By waveview
#375377
Vario lag is 1-3 seconds * so a 360 rotation in 7 seconds would have the vario signal to the pilot a massive 60-140 degrees out when trying to center the lift :(

How do pilots compensate for vario lag when they are thermaling at fast/slow 360's?

* http://www.ddsc.org.au/documents/manual ... ations.pdf
By old newbie
#375378
wow I am glad my vario does not have a 3 second lag
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By Wonder Boy
#375383
waveview wrote:Vario lag is 1-3 seconds * so a 360 rotation in 7 seconds would have the vario signal to the pilot a massive 60-140 degrees out when trying to center the lift :(

How do pilots compensate for vario lag when they are thermaling at fast/slow 360's?

* http://www.ddsc.org.au/documents/manual ... ations.pdf
You're vario lag should not be 1-3, sounds like it's broken.
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By CHassan
#375386
That depends, do you use the machine to tell you where lift is? Or do you use the machine to verify what you felt was lift?

I used a slow vario response setting for a long time. I always wanted confirmation that I started turning in lift. Not erroneous indication of lift. (stick thermals) I wanted to be able to rely on my gut.

I, more recently, have started using a quicker response with higher sensitivity. I still prefer to rely on my gut when I'm established in a thermal, but the constant 'beeps', 'boops', and 'booooooweees' helps remind me that sometimes not sinking as fast is the best available option!

....and that is MY opinion!
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By TjW
#375388
One of the biggest advantages of Frank Colver's original hang gliding vario over was how quickly it responded, compared to the sailplane varios people were using at the time. (or rate of climb instruments out of power planes, which were pretty severely damped/filtered/averaged.)

But my current vario has a pretty big lag. That's probably due to averaging.
Given my druthers, in light lift I'd druther have a quick responding audio, and use my integrating vario (the altimeter) to tell me whether I gained or lost in each turn. In stronger lift it doesn't matter quite so much
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By waveview
#375444
Wonder Boy wrote:
waveview wrote:Vario lag is 1-3 seconds * so a 360 rotation in 7 seconds would have the vario signal to the pilot a massive 60-140 degrees out when trying to center the lift :(

How do pilots compensate for vario lag when they are thermaling at fast/slow 360's?

* http://www.ddsc.org.au/documents/manual ... ations.pdf
You're vario lag should not be 1-3, sounds like it's broken.
Mike, the vario is one of the quality name brand models popular in hang gliding.

Placed the vario at floor level then lifted it quickly up over my head to a complete stop. The vario has STOPPED climbing at this point but the audio climb sound continued at a reducing tone for 4.8 seconds. Do other vario's do this?
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By Tormod
#375448
Varios have adjustments ranging from "nervous" to what you describe, time to read the manual!