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Old Apr 15, 2011, 07:30 PM
Renegade Eggroll
USA, IL, Chicago
Joined Jan 2011
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Explain the mechanics of bank and yank

I'm a new pilot and I flew a UMT-28 previously and now a HZ Super Cub. With the UMT-28, when I bank left, I push the stick left and while holding it left, move it down (up elevator). My UMT-28 always nose bank hard into the ground. I gather that it's the wrong way to bank and yank. How do I bank and yank properly? Do I push the stick left, return it to center and then down? Help?
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Old Apr 15, 2011, 07:43 PM
Shelter Kitty "Orange Death"
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United States, FL, Monroe
Joined Jan 2008
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The Cub has a ton of dihedral (wings angle up) this makes the plane want to right itself in a turn.
The T-28 not so much so you have to release the bank, holding it over will roll the plane into the ground.
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Old Apr 15, 2011, 08:35 PM
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I do the bank and the yank at the same time so that the stick is moving diagonally, though usually on a slight curve so that the bank comes in a bit before the yank.

The main problem you're probably having is that you're giving it too much bank and not enough yank; the yank part will help to keep the nose up but as the roll angle increases, the elevator just starts to cause problems.

For the T-28, you may want to add a bit of opposite rudder during turns. It's known as a coordinated turn and it helps to keep the nose up.
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Old Apr 15, 2011, 09:12 PM
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United States, CA, Alpine
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You have to vary your aileron input to keep the airplane in the same bank angle. Seems complicated, but eventually you will get it- holding roll input amidst a turn is not going to work out
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Old Apr 15, 2011, 10:36 PM
Registered User
Livermore, CA
Joined Sep 2004
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When you bank/roll a plane, there is less lift from the wings, as gravity pushes stright down. The steeper the bank the less the lift so the plane noses down.
So when you start to roll/bank the plane, you need to pull back on the stick(climb).
The quicker you roll/bank, the quicker you need to pull back on the stick.
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Old Apr 15, 2011, 11:33 PM
Renegade Eggroll
USA, IL, Chicago
Joined Jan 2011
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thank you very much for the explanations! This helps a lot. I'm definitely not pulling back on the stick enough now that I think about it. I'll practice on giving it some opposite rudder as well to keep the nose up.

Tom
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Old Apr 16, 2011, 03:56 AM
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Letchworth, Great Britain (UK)
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I find the biggest problem beginners at our club have, apart from the apparent change in left/right when the plane turns around to come back, is they move the transmitter stick far too much. Sounds to me like you might be doing that.

With an aileron model it doesn't take much stick movement to bank it, and you should try to control your movements so that the bank doesn't go beyond about 30 degrees. As others have said, you probably won't need to hold the stick over, for a model with little or no dihedral will stay where it's put until you give it some opposite stick. If it starts to bank too far during a turn, you have to ease off the aileron stick, or even give a bit of opposite stick, to get it back into correct attitude for the turn.

At the same time as you're controlling the bank with the ailerons, you need to pull a little bit of up elevator. It needn't be a lot, but the more you pull the tighter the turn will be.

Sounds to me like giving opposite rudder input may over-complicate things at your present learning stage. Just practice smooth bank/yank turns first. Oh, keep up a reasonable air speed too, because when you bank for a turn there's a chance you can stall because you've lost some of the lift when the model's on its side.
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Old Apr 16, 2011, 08:29 AM
Canadian Bacon
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Kingston, Canada
Joined Jun 2004
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Here's my take on it Just do a shallow bank , maybe 5 degrees, and use just enough ail. to hold that bank angle. You'll find you have to play with the ails. to hold that bank. At the same time, feed in enough elev. to hold the same altitude. If you give to much elev. you'll see it climb, so back off on the elev. Not enough elev. and it will drop, so crank in a little more up elev. Now practice doing very shallow figure 8s. This will help you get the feel in both directions so you don't get stuck in a rut by only being able to do turns in one direction, which I've seen to often. Keep increasing the bank angle till your comfortable with it and can do it by instinct. You'll find that every plane has different characteristics in this respect and what makes planes interesting. Sort of like people, no two alike. Hope this helps a bit.

Gord.
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Old Apr 16, 2011, 05:34 PM
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United Kingdom, England, Poole
Joined Nov 2010
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Quote:
Originally Posted by TP16 View Post
For the T-28, you may want to add a bit of opposite rudder during turns. It's known as a coordinated turn and it helps to keep the nose up.
Do you really mean opposite rudder?

I don't have a model with ailerons (just a 3-channel Champ), but I do also fly full-scale gliders. In those you always have to move the rudder in the same direction as the ailerons to compensate for the "adverse yaw" effect: the aileron creates extra drag on the up-going wing and with no rudder input the aircraft's nose would swing in the opposite direction to the turn. When you have a 15- to 20-metre wing-span, the resulting leverage makes the yaw effect quite severe and an aileron-only turn causes the glider to go sideways. For this reason, we have a piece of wool taped to the outside of the canopy: if it is pointing straight back then the turn is coordinated properly, but if it is pointing to one side then a rudder correction is needed.

I am told that most powered aircraft don't have so much adverse yaw and can usually get away with little or no rudder in a normal turn. However, I don't know how to fly a powered plane myself.

Moving the ailerons and rudder in opposite directions produces a "side slip" in which the glider is no longer pointing straight into the airflow. This leads to increased drag and a rapid descent, which can be useful if you are much too high on the landing approach.

For a turn to the right, the sequence would be:
  1. Look over your shoulder to check for other aircraft. (Obviously this doesn't apply to models, but for full size it is very important indeed!)
  2. Simultaneously apply right aileron, right rudder and a touch of up elevator.
  3. Monitor the angle of bank. On reaching the desired angle (typically 30 degrees), centralise the ailerons and rudder but keep the elevator up. The glider continues to turn.
  4. In a steep thermal turn, a bit of opposite aileron is sometimes needed to stop the angle of bank from increasing. If the nose drops, add more up elevator; if the nose rises then reduce the up elevator.
  5. To exit the turn, apply left aileron and rudder.
  6. When the wings are level, centralise the controls (including returning the elevator to neutral).

I would be interested to know if models behave differently...
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Old Apr 16, 2011, 07:56 PM
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ostrich

From my flight sim dogfighting and WWI readings on pilot instruction methinks they maximized their limited power performance or retained their 'energy' in the way you describe. Most of that logic was all about dogfighting. Eyes can't take the strain anymore but kinda' miss those evening skirmishes.
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Old Apr 17, 2011, 09:48 PM
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Impostor
Do you have access to a flight sim? Maybe look into getting one of the free ones like fms if not. Even if the physics may not be perfect on the free or cheap sims, I think they would be perfect for someone to get the hang of bank and yank turning.
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Old Apr 17, 2011, 11:05 PM
Renegade Eggroll
USA, IL, Chicago
Joined Jan 2011
788 Posts
I have Phoenix Sim. I fly in the sim sometimes, but the planes in it feels super stable for some reason. They don't' feel as twitchy as the real ones. I'm not sure if there are settings that I can tweak to make them feel a little more real.
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Old Apr 18, 2011, 12:19 PM
Ochroma Lagopus Tekton
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Blackstock, South Carolina
Joined Sep 2007
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Ostrich: What you're doing is known as a coordinated turn, and it is actually the correct way to turn an aircraft. Without the rudder imput even a powered plane will drag it's tail around a turn instead of tracking it neatly and efficiently around which, as you pointed out, is a Very Bad Thing when flying a sailplane for which drag is it's worst enemy
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Old Apr 18, 2011, 04:34 PM
fmw
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People of think of banking as turning the airplane. Actually you need elevator along with the bank to complete a turn. The rudder input is important in real planes because uncoordinated turns are uncomfortable for passengers. In a model plane, there are no passengers so you can get away with uncoordinated turns. Bank, apply up elevator and adjust the sticks to keep the nose going where it should go. Leave the rudder alone until you have that mastered. Then you can add in some rudder coordination.
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Old Apr 18, 2011, 05:53 PM
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Rhode Island USA
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Okay, so when I do want to try a Coordinated turn, which way do I turn the rudder? With the direction of the turn or opposite?
Confused
VP
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