Steep Turns

I know I'm late to this party, but I wanted to chime in as well. I think Averyrm had the best explanantion, but Grabo and Flyboy had good replies as well. Remember that the velocity of any point of an object in circular motion is, in a simplified form, V = omega x radius, where omega is the rate of turn. So if the center of motion of the turn is the down wing then r is zero and the velocity of the inner wing due to the circular motion is zero. The outer wing on the other hand has a velocity due to the circular motion of omega x r, where r in this case is the wingspan, for small bank angles. Of course this is a simplistic point of view in that the inner wing will still be traveling at some velocity due to its forward motion, and the center of the circle is usually not the tip of the inner wing.

But this will be the case for all turns, not just steep turns. As was pointed out, the rate just happens to be a lot higher for the steep turn, although the radius in the plane of motion is smaller than in a medium or shallow turn. What I mean by this is that the radius r that counts is the projection into the plane of motion. As the angle of bank become steeper, the wingspan that actually lies in the plane of motion becomes smaller until it's zero at knife edge.

But I digress. In medium and shallow bank turns the lateral stability is about equal to or greater than the effect of the increased lift on the outer wing due to circular motion. In steeper turns the overbanking tendency dominates. On the issue of adverse yaw. While the most commonly known is that due to aileron deflection, there is also adverse yaw in any banking as the angle of attack on the wings vary as one goes down and the other goes up . Since the lift vector is perpendicular to the relative wind, the lift vector for one wing usually point a little more forward than the other, leading to adverse yaw.

Although it took me a while to finally get through it, I'm almost done reading "Aerodynamics for Naval Aviators". Having a physics and engineering background made it a lot easier to understand, but I think it's a must read for all pilots who really want to understand the details in an applied manner. Another good read is "Emergency Maneuver Training" by RIch Stowell.

Regards,

Dave
 
Awesome reply!

That's what I wanted to say, but I just didn't have the time to type all that much... I'm a man of few words... /ubbthreads/images/graemlins/cool.gif
 
Alright, I'm dragging this one out from the depths of late summer 2004.

For a left steep turn.

1) Roll the plane to the left, 45º point
2) Then apply right rudder
3) Power as needed to maintain altitude
4) If you use trim, then trim.

Or

1) Full right rudder
2) Roll left into the turn to 45º
3) Power asneeded
4) Trim as needed

Eh? Which one?
 
I teach -

Roll into your 50 degree turn (commerical standards), add your power beyond 30 degrees where load factors become apparent, trim the aircraft so you dont have to fight with the controls, and monitor. Once we complete the first 360, I teach to lead with the rudder turning into the opposite direction in order to keep the airplane from wanting to gain altitude on the roll out prior to the second 360.

It works out pretty dang good.
 
Thanks merit. Will have to try that out in a few days. Now in the left bank, right rudder should be used. . . while in the right bank, left rudder should be used. Correct? Opposite of the turn, otherwise using the same side rudder will just speed up the outside wing and eventually a stall (of the slow wing) and then a spin will occur. . . correct?

How's my spin awareness?
 
I may have said that wrong - my bad..

What I meant was -

Lead the turn with the rudder (atleast in the Seminole) once you're coming back around after you've already done your first 360. Said another way, if we turn first to the left keep it coordinated once we're getting to roll out and turn to the right, I'd step right with rudder and lead the turn to the right with right rudder.

Yeah, all that stuff about stalls and spins? Umm... no, none of that will happen. As long as you keep your airspeed up in the steep turn, dont worry about spinning.

You a new pilot?
 
Just keep the airplane coordinated during your steep turns. Dont worry at this point about fancy rudder inputs. Just keep it coordinated and look outside and you'll be fine. Dont worry about spinning the airplane in a steep turn also.

Just because one wing is traveling at a slower rate doesnt mean it'll stall as in a turn.

You'll learn more about it as you go on. Dont be hesitant in steep turns. Nothing to worry about at all.
 
I know. :) Thanks for the confidence boost. I know I can do them. It's just odd being the only one in the plane. . . :)

And the 1.5g's (go ahead, call me a whimp).
 
I think you may be worried about a spin and/or stall. Just remember that spins and stalls occur usually at very slow airpseeds and uncoordinated flight.

Keep the ball centered.

Make sure you keep your eyes out of the cockpit and on the outside horizon during your turns.
 
P-Factor. That's what does it. Anytime you have to add back pressure, you have to add right rudder. It is especially noticable in the steep turn to the right. As you add back pressure goung past 30 or so degrees, you have to add right rudder, and hold it, while you add elevator back pressure to hold the nose up. This added right rudder will increase the overbanking tendency and you will have to hold left aileron. This is always the case in a steep turn to the right. If you are not holding a little right rudder in a right steep turn while holding the nose up, then the ball will be about a half ball out to the right. Try it.

Left turns are not so noticable, and really depends on how true the airplane is rigged. Theroetically, you should need a small amount of right rudder in the left turn because you still have P-Factor, but it isn't so noticable, but it is definitely noticable in a steep turn to the right.

The underlying fundamental control input is that you should know that anytime you pull back on the elevator, you have to push on the right rudder, regardless of your attitude.
 
Why do you have to keep the rudder pressure in? and why the opposite aileron (imagine its cause the overbanking tendicies)?

An aircraft in a steady turn is rotating about two axes: it's pitching and yawing. In a turn to the left, the aircraft is yawing at whatever rate is necessary to keep it aligned with the relative wind. However, the yaw rate creates its own relative wind due to the rotation of the aircraft. In a left turn, the yaw is counter-clockwise looking down from the top. This motion tends to dampen the vertical stabilizer's ability to keep the aircraft pointed into the wind. You need rudder to help it a bit.
 
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