Overbanking Tendencies

chris

chris

Well-Known Member
Hey guys,

Is there an easy way to try to explain why the a/c has an overbanking tendency in a climbing turn and why it does not have one in a level or a descending turn? I am working on my instructor rating now and I want to try to use an explanation that is accurate, but also easy to understand and demonstrate.

I find the explanation that "the outer wing travels faster and has a higher AOA" is a little difficult to get the student to visualize and understand it properly. This is how it was explained to me, and I never really did understand it all to well.

Specifically, I cannot try to provide an explanation to the following questions:

1) In a level turn, both wings should be at the same AOA, but the outer wing still travels faster. Why is there no overbanking tendency then in a level turn?

2) In a descending turn, the inner wing is supposedly at a higher AOA, while the outer one travels faster. There is no overbanking tendency because these effects are offset; however, if the inner wing is now at a higher AOA, should not that wing have more drag, and shouldn't there be a yawing tendency towards the inside of the turn? (i.e. aileron drag occurs because one wing is at a higher AOA than the other... in this case, the inner wing is at a higher AOA... shouldn't the aileron drag be higher on the inner wing then?)

Well, that's all for now. Thanks in advance!

Chris.
 
Overbanking tendencies are there in level turns. Thats what steep turns are. Any turn where you are having to hold opposite aileron to maintain bank angle is demonstrating over-banking.

Overbanking occurs as a result of air travelling faster over one wing (the outside one) than the other. Therefore, that wing produces a tiny bit more lift than the inside wing, causing the aircraft to have a tendancy to keep banking despite neutral controls. This can occur at any airspeed. The slower the airspeed, the less the bank angle will be when you begin experiencing overbanking...and vice versa- the higher the airspeed, the steeper the bank angle will be.

Next time you are up flying, do some turns during slow flight and notice that at some relatively shallow bank angle, you will need to start holding opposite aileron to maintain it. Then notice that when you're doing steep turns, its a higher bank angle when you have to begin using opposite aileron to maintain it (because of the higher airspeed).
 
[ QUOTE ]

1) In a level turn, both wings should be at the same AOA, but the outer wing still travels faster. Why is there no overbanking tendency then in a level turn?



[/ QUOTE ] I actually did this today in my PPL training, if i'm correct you would apply rudder as necessary to have a coordinated turn, i think this is what you are talking about, punch me if im wrong
smirk.gif

Ryan
 
PUNCH!
grin.gif


What you're thinking of is adverse yaw. When you make an aileron input, the aileron that moves downward and raises the wing creates drag and yaws the airplane in the opposite direction of the bank. The rudder is used to counter act this yaw and should be neutralized when you neutralize the ailerons.

The overbanking tendency happens when the wing on the outside of a turn moves faster than the wing on the inside and creates more lift, increasing the bank. Coordinated rudder AND aileron are used to correct for overbanking.

Clear as mud?
 
You must log in or register to reply here.
Back
Top