Can somebody tell me how to turn?

[mdennis]

I have been flying RC for many many years, but gliders for only the last three or four. (Not exclusively)

I can tell when my plane is in rising air, it doesn't always have a great signal, It doesn't necessarily speed up, or the tail doesn't always go up or down, but somethings happening I didn't put there. I can tell when it's in sink for similar reasons, although sink is generally more dramatic. All of my planes are a little different.

I typically fly a straight line until I get bumped, then continue that line until I hit he sink on the other side. I turn back and hopefully get back into the rising air. My plane starts to rise and I begin to try and core the thermal drifting my imaginary thermal backside with the wind, but generally just trying to pay attention to where the lift is best. Overall though, I am losing too much altitude in my turns. When I am flying straight I am rising, when I turn I am losing.

Mixing my rudder with my ailerons helps sometimes, but seems to really hurt when I am in sink. On my larger planes I have a lot of differential in, On my DLG I have none, based on a Mark Drela study. My CG's tend to be pretty far back and are set based on dive tests, inverted flying and trim necessary from a straight and level flight condition.

Should I be trying to keep my fuselage level or my wings level? Airspeed can't remain constant due to upwind and downwind conditions, but should it generally be faster or slower than when I am searching for lift? Should I be switching from camber to neutral to reflex depending on the planes direction and the wind? I don't mind flying and learning all of this on my own and maybe it's just something that each of us must learn on our own with each different plane, but I can't help but think that, like most things, the fundamentals must be mastered first. So what are the fundamentals of turning?

[BMatthews]

Elevator control is key to thermal turns. You need to keep the model flying at it's best speed and that is generally somewhere close to the minimum sink speed and not the best L/D speed. Once in a thermal you're only interested in climb rate, hence slowing it down to the min sink. Elevator needs to be fed in smoothly as the bank is set up and maintained and controlled until the model is rolled out of the turn and the elevator is progressively reduced until the model is back to level.

The wings obvioiusly need to be banked to avoid any slipping and thus drag. The fuselage needs to sit at the angle related to the min sink speed. Once in the turn do NOT try to alter speed to allow for any wind changes. Just try to look through the speed changes and keep the model flying at it's best min sink speed.

Now having said all this a model in turning flight has more drag and a faster sink rate than a model in level flight. It's working harder when in the turn so it's sinking faster. So it follows that keeping the turn as large as possible while still staying in the lift core is the way to go. I've often noticed birds flying in thermals and turning in larger circles that only have climbing going on in one part. I've come to believe that they also live by the bigger efficient turning pattern and know they will only get the "good stuff" once per turn but as long as they are in the bouyant air the rest of the time they are not loosing. Perhaps you can set up to follow this sort of pattern and stay in the thermal but only pass through the faster rising core for part of the turn.

[Ollie]

Use your flying skills. Develop your flying skills. Bring out the right flight skills for the plane and for the perticular thermal. Your "tool box" flying skills for a perticular job. Map out the lift using wind changes in speed and direction, birds, insects, leaves, smoke, the response of the plane. Develop your sensitivity to the lift meaning clues.

"Learning To "See" by Mike Lee

"While there is no doubt that a large number of people must wear glasses for perfect vision, there is a little-known fact that people only see what they want to see. Most of the time, we see only those things which are in close proximity to us and ignore the rest. But when we fly aircraft we must be able to see or we are lost. There is a way to help yourself.

"Good eyesight doesn't require you to borrow the eyes of an eagle to be great. Even if you wear glasses, the trick to seeing well is to train yourself to do so. This is really easy to do, and you can do this anytime that you are awake and looking around.

"The first thing to do is try to notice everything around you. Look especially for details of items like the leaves in the trees, not just the trees. Look for the name emblem on a car as well as the entire car. Watch for the things within your peripheral vision without moving your eyeball from the spot it is focused on. After awhile you will find that you are seeing things you didn't see before.

"Next, move on to more distant objects. Don't just look at a mountain in the distance, look at the detail of the mountain in the distance. When you are out driving, look ahead, way ahead, for the street signs and read them. You will soon find that you are teaching yourself to see better. Your eyesight was always there for you -- it just wasn't fine tuned to see everything.

"If you practice seeing with your eyes, you will soon find that your ability to identify the altitude of your aircraft at distance is easier than before. You won't worry about whether that last control input should have been left, or was it right? Consequently, you will recognize lift faster and run from sink sooner. It is a very conscious effort to train your eyes to see, but the results will last you the rest of your life."

That means that you "see" with you skilled, trained mind more than your eyes. Even a blind person "sees" things because he notices them better than you. A deaf person can read your lips.

[Ollie]

There is more.

Think about flying skill training from a reflex point of view. Reflex time type are automatic nervious reflex ~0.1 sec. (burning touch), higher-mind thinking reflex <0.4 sec. (think about it) and anticipation (no reflex). At an airspeed of 20 feet per second, reflex length in feet is 2 feet target for 0.1 sec automatic reflex, more than 8 feet for <0.4 sec. higher-mind reflex and zero length for anticipition.

What kind of goal? At no change position of goal get anticipition zero length but if it is a moving goal you need anticipition zero length plus more than 8 feet higher-minded reflex.

Your skill flying training is a purpose to make the reflex smaller in length and time for your standard goal.

[mdennis]

Ollie,
If I understand what you are saying correctly; I need to learn to fly ahead of my plane and anticipate what it will need. Much like when you drive a car you look ahead to where you are going, but remain cognizant of what your car is doing. Or like when you first learned how to fly and RC plane you had to think about what is left and right, but now do it without thinking about it.

[Ollie]

Right on, Dennis!

Focus your mind about flying the plane and the air movement and other lift cues. Your goal to intergrate data about this flying experence about it within a split second. Don't focus your mind about the girl friend or your bank balance when you are flying.

[davidjensen]

I'm no expert but I do see many glider pilots banking their planes too much in a turn. Each plane is different and the ideal bank angle is plane specific and the correct use of rudder (not necessarily mixed with aileron) is critical to a good turn.

[BMatthews]

Being mentally ahead of the plane is part of it but a larger part of what I think Ollie quoted or wrote is more about YOU being in tune with what the airplane needs in order to know what is needed for you to retrim your Tx to switch from one flight mode to the other. The two key modes being best L/D or "most efficient travelling speed" to minimum sink speed and how to hold that sort of performance while in a turn. Being observant and comparing how your model is flying in relation to it's surroundings is a large part of this.

You need to spend some time trying various turn settings and turn sizes and get to know when and how the model responds best for each turn size.

But as a general "feel good" statement I've found that all my models over the years did quite well with minimal control throw added. Even surprisingly steep turns can be maintained with less than you think.

Once you know the turn parameters for your model and various sizes of turns the transition becomes the goal. You need to test and practice to learn just how much elevator to feed in during the transitions so the model looses as little as possible from level to turning. With practice it will enter a turn with no additional loss over what it would have had while in level flight.

So it's part philosophy and part practice.

Oh, and adding control inputs creates a lot of drag if you try to make the plane alter it's course too quickly. You'll get far less braking effect if you learn to use a little bit of control input and just be patient while the model slowly rotates into the desired turn. This also makes it far easier to input the proper elevator trim. A quick jab at the controls to make a model snap into the turn will create a lot of drag and upset the path of the model to the point that it makes it hard to see what the model needs and even if the thermal is still there until you get it settled back into a steady state and can see how it's reacting. Now and then a snappy entry is needed but I've found that it's by far the exception than the rule. Slow and smooth is where it's at.

[xtc]

I'm no expert but I do see many glider pilots banking their planes too much in a turn. Each plane is different and the ideal bank angle is plane specific and the correct use of rudder (not necessarily mixed with aileron) is critical to a good turn.
i also notice this alot but i also notice that sport plane pilots or power plane pilots have a lot less sence for drift than glider pilots

a great number of pilots still have there minds on the ground rather than in the air

turns in relation to the ground will cause pilots to turn more aggressive rather than drifting with thermals

i really got a laugh a while back when i had a guy that was on CANADA`S national team for pattern planes a told me that you MUST apply throttle before all downwind turns as to carve around the turn with power to keep the circle co-ordinated or round and i was then told that the only thing rc pilots have to relate airspeed is the ground

my point is;; thermals drift so your turns will also ,,anything else is driving around the sky in relation to the ground

why cant your airspeed be constant on up-wind verse downwind turns ??or is that ground speed?

[mdennis]

Thanks you for pointing that out. My terminology was incorrect. I think you want to maintain the same airspeed. Ground speed will change as you go upwind or downwind.