A very basic question

Hi guys,

Unlike the elevators and rudder that change an aircraft's pitch and
yaw with no other secondary effect, why does the banking of wings by
the use of ailerons not just roll an aircraft but also produces a turn
(yaw)? Logically, one would expect an aircraft to keep going straight
ahead even if the pilot banked the aircraft left or right. Where does
the turning effect come from?

Is there a website you know of that can teach me such basics, without
having to bug you?

Cheers,

Ramapriya

Unlike the elevators and rudder that change an aircraft's pitch and
yaw with no other secondary effect, why does the banking of wings by
the use of ailerons not just roll an aircraft but also produces a turn
(yaw)? Logically, one would expect an aircraft to keep going straight
ahead even if the pilot banked the aircraft left or right. Where does
the turning effect come from?

Is there a website you know of that can teach me such basics, without
having to bug you?

Cheers,

Ramapriya


Rudder most definitely adds roll as a secondary effect.
In fact, I use rudder to momentarily keep the wings level when I'm changing
maps, etc.
At low speeds, when the ailerons are not that effective, rudder can be much
more effective.

As to the aileron, think of the relative wind on the wings.
With an aileron dropped (looking like a flap), there will be increased drag.
Of course the other one goes up, but I don't think the resultant force is
equal on both wings.
Thus, yaw results.
While it seems intuitive to me, I probably don't have the best explanation,
so can anyone else elaborate?

Adam
N7966L
Beech Super III

As to the aileron, think of the relative wind on the wings.
With an aileron dropped (looking like a flap), there will be increased
drag.
Of course the other one goes up, but I don't think the resultant force is
equal on both wings.
Thus, yaw results.

Brian, are you stating that this yaw causes the turn?, actually this is
adverse yaw and resists the turn.

Come, lets step into my flying laboratory, the Grob 103, and we'll explore
that interesting concept called adverse yaw.

BT

"BTIZ" wrote in message
news:K97jd.86842$bk1.136@fed1read05...
As to the aileron, think of the relative wind on the wings.
With an aileron dropped (looking like a flap), there will be
increased drag.
Of course the other one goes up, but I don't think the resultant
force is equal on both wings.
Thus, yaw results.

Brian, are you stating that this yaw causes the turn?, actually this
is adverse yaw and resists the turn.

Come, lets step into my flying laboratory, the Grob 103, and we'll
explore that interesting concept called adverse yaw.

BT
Inside rudder will most definitely produce bank which will produce turn
exactly as Brian said it would. There is a difference between adverse
and complimentary yaw. Actually, there will be no adverse yaw if inside
rudder alone is used to induce complimentary yaw. Only aileron
application into a bank with no inside rudder will produce adverse yaw.
If complimentary yaw (inside rudder) is used with no aileron, the speed
difference between the retreating inside wing and the forward moving
outside wing will cause bank, which will be a direct secondary result of
the complimentary yaw being produced.
In other words, insider rudder will most definitely produce bank as a
secondary effect and as such will produce turn...assuming no anti turn
control input is present.
Dudley Henriques
International Fighter Pilots Fellowship
for email; take out the trash

I was always under the impression that in most light a/c, the dominate
rolling effect from 'inside' rudder is the result of dihedral (or
alternatively, sweep back). RC modelers are pretty adept at setting up
aircraft for 'pure' yaw from rudder input - no dihedral, symmetrical layout,
etc. Or setting up aircraft to bank and turn without ailerons - lots of
didedral.

Though I'd agree that the "forward motion of the outside wing" explanation
accurately predicts the rolling effect from rudder input that occurs on most
a/c - which is ok for training purposes.

"Dudley Henriques"
snip
If complimentary yaw (inside rudder) is used with no aileron, the speed
difference between the retreating inside wing and the forward moving
outside wing will cause bank, which will be a direct secondary result of
the complimentary yaw being produced.
In other words, insider rudder will most definitely produce bank as a
secondary effect and as such will produce turn...assuming no anti turn
control input is present.
Dudley Henriques
International Fighter Pilots Fellowship
for email; take out the trash

"Maule Driver" wrote in message
om...
I was always under the impression that in most light a/c, the dominate
rolling effect from 'inside' rudder is the result of dihedral (or
alternatively, sweep back). RC modelers are pretty adept at setting
up
aircraft for 'pure' yaw from rudder input - no dihedral, symmetrical
layout,
etc. Or setting up aircraft to bank and turn without ailerons - lots
of
didedral.

Though I'd agree that the "forward motion of the outside wing"
explanation
accurately predicts the rolling effect from rudder input that occurs
on most
a/c - which is ok for training purposes.

I would agree with this completely. Dihedral contributes heavily to the
lateral stability of the aircraft if sideslip is present to be sure. The
prime contribution of dihedral is in the development of a stable rolling
moment with sideslip, which is consistent with what most of us are
saying.
The problem with answering many questions in aerodynamics is that there
isn't one single example or answer that will suffice.
(Lift is a PRIME example of this. ) Anyone trying to explain lift in a
simple sentence will find a slew of missing data soon to follow :-) The
problem in aerodynamics is that in much of what is happening, several
explanations are in force physically together at one instant in time.
The way we look at dihedral in the flight test community is primarily as
it's effect on the lateral stability scenario which relates with
sideslip present to relative wind, differential in angle of attack,
changes in lift raising a windward wing producing stability.
I think we're both on the same page, and dealing with the same effect
since all of what we're discussing is present in complimentary yaw IF
dihedral is present.
Now, if we inject an airplane into this equation like a Cessna 195 for
example.......... :-))))
Dudley Henriques
International Fighter Pilots Fellowship
for email; take out the trash

Dudely.. he said turning by banking only.. he said nothing of "inside
rudder"
at least not the way I read it

BT

"Dudley Henriques" wrote in message
news

"BTIZ" wrote in message
news:K97jd.86842$bk1.136@fed1read05...
As to the aileron, think of the relative wind on the wings.
With an aileron dropped (looking like a flap), there will be increased
drag.
Of course the other one goes up, but I don't think the resultant force
is equal on both wings.
Thus, yaw results.

Brian, are you stating that this yaw causes the turn?, actually this is
adverse yaw and resists the turn.

Come, lets step into my flying laboratory, the Grob 103, and we'll
explore that interesting concept called adverse yaw.

BT
Inside rudder will most definitely produce bank which will produce turn
exactly as Brian said it would. There is a difference between adverse and
complimentary yaw. Actually, there will be no adverse yaw if inside rudder
alone is used to induce complimentary yaw. Only aileron application into a
bank with no inside rudder will produce adverse yaw.
If complimentary yaw (inside rudder) is used with no aileron, the speed
difference between the retreating inside wing and the forward moving
outside wing will cause bank, which will be a direct secondary result of
the complimentary yaw being produced.
In other words, insider rudder will most definitely produce bank as a
secondary effect and as such will produce turn...assuming no anti turn
control input is present.
Dudley Henriques
International Fighter Pilots Fellowship
for email; take out the trash

"BTIZ" wrote in message
news:Lphjd.90058$bk1.21776@fed1read05...
Dudely.. he said turning by banking only.. he said nothing of "inside
rudder"
at least not the way I read it

BT

I admit the question is a little vague to say the least. I think I might
have got caught up in that "turn"(yaw) thing and read it to mean
complimentary yaw producing turn as a secondary effect.
I read it as asking several things that were not exactly correct in
premise to begin with!

For example;
"Unlike the elevators and rudder that change an aircraft's pitch and
yaw with no other secondary effect,"

I have a bit of a problem with this premise before even getting into the
"question"
:-)
Then we have this;
"why does the banking of wings by
the use of ailerons not just roll an aircraft but also produces a turn
(yaw)? "

I read his context as aileron being used and producing turn which in the
turn (inside context) would be complimentary yaw.....which of course
wouldn't be the secondary effect of using aileron to begin
with.........are you following this........cause I'm getting lost!!!
:-)))
The parenthesis (yaw) opens up a whole deck of cards since banking the
airplane with just aileron would produce adverse yaw; not complimentary
yaw, and it will also as a secondary effect after adverse yaw had
stabilized, produce turn if not held back with anti turn controls. It's
puzzling the way he worded it really.
I'm not sure really what he was asking at this point!! :-)

Anyway, the answer for uncoordinated turn entry using various isolated
control inputs would be if aileron alone....adverse yaw followed by turn
after stabilization and vector split;
and inside rudder alone; turn as bank is introduced as the secondary and
the lift vector splits.
You are completely right of course about dihedral effect!
Anyway....I think I'll leave this for you guys to play with. I'm going
to bed!!
:-)
Have a good one,
Dudley

"The Weiss Family" wrote in message ...
Unlike the elevators and rudder that change an aircraft's pitch and
yaw with no other secondary effect, why does the banking of wings by
the use of ailerons not just roll an aircraft but also produces a turn
(yaw)? Logically, one would expect an aircraft to keep going straight
ahead even if the pilot banked the aircraft left or right. Where does
the turning effect come from?

Is there a website you know of that can teach me such basics, without
having to bug you?

Cheers,

Ramapriya


Rudder most definitely adds roll as a secondary effect.
In fact, I use rudder to momentarily keep the wings level when I'm changing
maps, etc.
At low speeds, when the ailerons are not that effective, rudder can be much
more effective.

As to the aileron, think of the relative wind on the wings.
With an aileron dropped (looking like a flap), there will be increased drag.
Of course the other one goes up, but I don't think the resultant force is
equal on both wings.
Thus, yaw results.
While it seems intuitive to me, I probably don't have the best explanation,
so can anyone else elaborate?

Adam
N7966L
Beech Super III

Because when the wing is level, the lift is up. When the wing is
banked to the right, the lift is also tilted to the right pulling the
plane in the direction. Same for the left.

Bryan

"The Weiss Family" wrote in message ...
Thus, yaw results.
While it seems intuitive to me, I probably don't have the best explanation,
so can anyone else elaborate?


Tilting of the lift vector also results in a turn.