The black art of gliding!
Author: Ivan Anissimov
Hello to everyone who is interested in flying lines.
Line flying is not that critical as ability to launch and land. You might be flying happily for years without being aware that pilots around you are searching for some elusive lift lines. I know-I did. But at some stage you might get bored with their consistently better glides and try to figure out what the heck going on. Placebo is a powerful tool after all.
This time for change I was actually asked to share my thoughts of flying lines. And I got some free time, as it is winter even in Queensland. So, here is my imaginary picture, which might be not related in any way to actual reality and might be not working for anyone apart from me (fingers &toes crossed☺).
Dennis Pagen said that it is always better to have some model in mind, even if it is wrong in parts or all together. Time and experience would allow you to verify or prove wrong some part of your model and you can improve it or find one better. It is like clay for potter, eventually it might turn up in something real and even beautiful. But with no clay you can’t be a potter, you would be just a day dreamer with no hope of making anything.
So, here is my clay, like it or not, but everyone welcome to use it for their own vase or night vase, whichever you need more.
I was always wondering while flying in competitions: why some pilots are staying higher on glides? Especially when I realise that it was the same pilots most of the time. Even more disturbing was the fact that I was never one of them☹.
In earlier days I was satisfied with fairly simple explanations: Enda got the photo nobody else can get and Fred can fly his reserve and still win the comp. Quite a few years later I managed to get decent glider (with decent harness, but that is another story), and found that few pilots annoyingly often glide noticeably better on the same glider as mine. “Just follow them” tactic never works, as you need much better glider to be able to follow anyone. So I had to come up with something else.
After few seasons of asking stupid questions and listening to everything I can hear, I formed my own model and few simple enough responses to the most scenarios during my flights, based on this model. I believe that it works for me, so I will stick with that for now, but will change it as soon as I will find something better.
Here are few assumptions I used to base this model on:
As one smart guy said, what’s coming up must come down. No sh#&t, the air. Warm – up, cold – down. No one arguing, but the question is: how? In what pattern? Is it thermals and blue holes? Or conversion lines and something opposite? Or hexagons? Or that waves with lenties on top? In my model it is all of the above and something else, something that other pilots call “lift lines”. I also noticed a lot of confusion existed in definitions and determination of differences between types of lift listed above. The lift lines I would describe below are just a picture from my mind, nothing more. It might not exist anywhere else, so don’t get too mental or judgemental about it.
Here it is: parallel invisible lines of sinking and rising air around 50-150 meters wide with not much distance between them. Sink/rise rate from close to nothing to around 0.3-0.5 m/sec. If it is any higher I would treat as a thermals or conversion, depending on the day. Most of the times they are parallel to the wind direction and can change their direction, as a wind does, without much notice. It also could be different directions at different heights. Few sets of different lines from different air mass could get mixed up, similar to waves from stones thrown into calm water by my kids (when I got four of them, it becomes mind boggling ☺).
Lift lines also could run parallel to the ridges, roads, rivers, etc (it is all in my mind, remember? I can even draw few more, when I really desperate☺). I have suspicion that these lines has different nature and causes, but I am happy to treat them in the same way when I am flying, as lift is lift anywhere, even in Tasmania.
Vertical size: I would look for them from ground to cloud base and they are continues, in my picture anyway. Tilt: the similar nature as thermals, i.e. nothing if parallel to wind and anything if it is not.
Vertical cut view: hair comb with widish teeth, width of teeth is similar to their spacing.
That is the best I can do in descriptional part. All numbers are come mostly from how far I prepared to go when I searching for lines. If there is some bigger picture, and I am sure there is, I am not too concerned about it, as I can’t use it in my flying. In other words, I would not go for very good lines in New Zealand when flying in Bright.
Now, implications of believing in lift lines:
Less sink on glide and more height at the end of it, capt’n obvious…
More thermals, if you follow lift lines, as thermal would not go up through sink lines.
Less sink, as sink can not go down through lift line. Sinky air will always go down through sink lines.
‘Feel good’ feeling, as you watch the green line on XCSoar or other pilots got hammered in sink line just 40-60 meters next to you.
Where are these lift lines?
As thermals, exactly where you will find them. Just keep an eye on them and they might move from my mind into the real world ☺. They are everywhere.
How to spend more time in lift lines?
That is easy: stay away from sink lines☺. If you see other pilots gliding sink line, don’t follow them. If you will fly a bit upwind from them you might just find a better line. And if you find more sink or they will find thermal, it would be quicker and easier to get to them with tail wind. Then you will find that separation distance, when you still can get to them, but they could not get to you because you are too far of course line and upwind, and you might get your lucky (or unlucky) break from gaggle. But that is more about tactic, isn’t it? Lets go back to our lines.
If you see someone gliding better on the same class glider – move towards them and see if you might glide better then them with the same speed. Maybe move a bit (50 meters bit) further and find more lift there. When you will find a sink, use it to your advantage, stay away from it.
As lift lines not always aligned with your task direction, you’d be better crossing sink lines perpendicularly. I treat them as mini valley crossings.
When you are not in competition and don’t need to be on full bar all the time, you can use a “dolphin technique”, i.e. slow down in lift and speed up in sink.
Correct your course line with light application of weight shift or small input on rear risers. It has to be very light and incremental, without causing pendulum or rocking, otherwise it is very difficult to notice small changes in sink rate what you are chasing.
Little adjustment to direction of flying should keep your vario happy when you following lift line. If vario is less happy – turn back. If you lost it completely – try to get out of sink line by crossing it at right angle if you can, don’t fly along sink line and wait till it finishes because you might meet ground before that.
Craig recommends to keep your course deviations under 25-30 degrees for thermals seeking. It would be logical to use a bit less for line flying, as gain from use of lift lines are much smaller then from thermals. But as I only use it for short distances (30-100 meters), it kind of evens it out.
The main thing is: you only do it when you have nothing better to do, don’t try to fly lines when your glider is gone. Please, be safe and have fun.
Don’t forget that what I just shared with you might be just figment of my imagination!☺
CU on hill somewhere. Say hello.
Ivan
Author: Ivan Anissimov