Leading Turns With Rudder

"toad" wrote in message
...
On Aug 2, 7:35 am, "user" wrote:
Then you're talking about a mental game, which is fine. Focus on the
rudder
since it requires a larger movement at low speed.

.... snip ...

The question
in my mind is, does the original post's premise of a regimen of

"...the FIRST thing you do is feed in rudder. On his 1-5 list of making a
turn in a glider, #1 is rudder (as its own separate input)."

produce a good pilot? At anything more than a few knots above MCA, this
formula will lead to a slewing nose, in equal proportion as I would expect
to see in an underruddered turn entry near MCA.


Yes, it is a mental game. The instructor's job is to train the
student to fly correctly. The talking is just a means to the end. I
don't care if the instructor tells the student to first yell "olly
olly oxen free" before he turns. If the student performs a good
coordinated turn entry, then the instructor has done their job.

Todd
3S

Well, yes, but...

The goal should be to train pilots for a lifetime of safe, high performance
flying. Merely training them to the standards needed for solo or the
practical test is shortchanging them. Beware the knock on ramifications of
"primacy".

If taught to "lead with the rudder" when in fact the goal is simultaneous
application of rudder and aileron, that will come back to bite the trainee
when feet reaction times improve with increasing experience. "Lead with
rudder" is, in fact, only a shortcut that helps the instructor move the
student along faster. In the long run, it puts the student at risk for
skidding turns and stall/spin accidents.

The fact that certain big wing gliders and antiques actually benefit from
this technique doesn't excuse teaching it to primary students. The student
should first learn to do it 'right' and then learn the exceptions.

Teach them correct theory and help them use their feet in coordination with
their hands. It will be hard for them to use their feet in coordination
with their hands at first, but they will learn to do it eventually.

If you want your student to improve coordination of turn entries, try "use
less aileron" rather than "lead with rudder". Or: "Dont use more aileron
than the rudder can cope with".

Bill Daniels

This battlefield is littered with straw men.

Maybe so, maybe so... There is a mysterious figure, left power CFI flying for soaring who
may or may not corporally exist:

http://www.pilotpsy.com/index.html

Sarah



user wrote:
He says... from the lotus position, index finger on thumb, palms turned
upward, and fingers spread. Be the glider. Hmmmmmmmmmm.... Hmmmmmmmmm....

Maybe someday I'll reach that plane (pun intended). In the meantime, the
best I can do is manipulate the controls to keep the string straight and the
speed within a knot or two of where I think it should be. Beep, beep,
beep... Hmmm... Now where did I leave my copy of The Zen of Gliding?

:-)


"noel.wade" wrote in message
...
I probably shouldn't leap back into this mess, but let me just point
out one more thing:

People tend to think about stick movements and pedal movements when
they talk about "coordinated" flying.

But the truth of the matter is that the airplane doesn't CARE what
goes on in the cockpit. It cares about how the air flows over the
craft and the control surfaces.

"Flying coordinated" means making WHATEVER control inputs are
required, in WHATEVER sequence necessary, to keep the airflow as
orderly and efficient as possible.

IMHO the best pilots are the ones who "detach" themselves and shift
their Point Of View to that of the aircraft itself. They aren't
thinking about the flight in terms of how they perceive it as an
occupant from their particular seating position or their control
stick. Thinking in terms of the aircraft and the air around it is
infinitely better than trying to act as a manipulator of levers and
pulleys inside a tube.

--Noel

At 15:26 01 August 2008, toad wrote:
On Jul 31, 6:59 am, "user" wrote:


Slewing the nose before banking... every time you turn?

"Leading with the rudder" does NOT equal "Slewing the nose before
banking" !

You can lead with the rudder and still get a coordinated turn entry.
You might only lead by a fraction of a second, but you can push on the
rudder before the stick. If that is what works best in the glider
that you are flying.

Todd Smith
3S




I agree that it's very glider-related: in some machines I've flown
(especially those with larger and/or multiple spans) there is not enough
rudder to coordinate with full aileron deflection at normal thermal entry
speeds, so a way to counter that is to apply rudder for a longer duration
(before and after aileron input) or more rudder / less aileron (slower
entry). As this is a _transient_ situation and results in improved
coordination and control, I can't get too worried about it; if a training
glider requires similar inputs to fly nicely then why not mention this?
Better than a student losing confidence because their turns feel a bit
imprecise and they don't know why? (I assume they've been taught to turn
the ¨proper¨ way to begin with...)

From what I've seen, I'd say it's much more important to eliminate the
tendency, once turning, to _continuously_ hold rudder deflection into the
turn along with out-turn aileron (lack of comfort with banking?) We all
know where that leads, yet I've seen it demonstrated by some fairly
experienced pilots who were unaware of their habit.

At 12:55 04 August 2008, Ed Downham wrote:
I agree that it's very glider-related: in some machines I've flown
(especially those with larger and/or multiple spans) there is not enough
rudder to coordinate with full aileron deflection at normal thermal
entry
speeds, so a way to counter that is to apply rudder for a longer
duration
(before and after aileron input) or more rudder / less aileron (slower
entry). As this is a _transient_ situation and results in improved
coordination and control, I can't get too worried about it; if a
training
glider requires similar inputs to fly nicely then why not mention this?
Better than a student losing confidence because their turns feel a bit
imprecise and they don't know why? (I assume they've been taught to
turn
the ¨proper¨ way to begin with...)

From what I've seen, I'd say it's much more important to eliminate
the
tendency, once turning, to _continuously_ hold rudder deflection into
the
turn along with out-turn aileron (lack of comfort with banking?) We all
know where that leads, yet I've seen it demonstrated by some fairly
experienced pilots who were unaware of their habit.

Even with a training glider which requires "lead with rudder" for a full
deflection thermal entry turn it is not necessary for a normal turn entry
with less aileron deflection (The Grob 103 is a perfect example) The Grob
enters a turn in a co-ordinated manner provided the correct amount of
aileron is used simultaneously with rudder to balance. The original point
was teaching lead with rudder to ab initio students and this is clearly
not necessary and bad practice. When teaching turns to ab initio students
no-one teached full aileron deflection do they? It is a technique which
can be introduced to more experienced pilots when they need to use full
aileron deflection for a clean thermal entry, and is perfectly valid as
long as the pilot is ware of the pitfalls of applying large amounts of
rudder.

Better straw men than the real thing...

Bill has a good point. Hard to say how many of our little expediencies lead
to inexplicable accidents farther down the road!


"Nyal Williams" wrote in message
...
This battlefield is littered with straw men.

In article , "user" writes:

Nontheless, the rudder balances aileron drag.

To be more precise, the rudder primarily balances the fore/aft
tilting of the lift vectors on the left and right wings,
which is a result of _roll rate_. The aileron drag difference
has a much smaller contribution.
The PDF diagram in this link illustrates the effect:
http://www.rcgroups.com/forums/showp...0&postcount=31


Coordination is simply defined
as balancing the yaw moment from the ailerons with a SIMULTANEOUS and
opposing yaw moment from the rudder. The amount of rudder needed to
compensate for aileron drag is inversely proportional to speed.

Correct.
But the required rudder deflection is actually inversely proportional
to CL, and hence to the _square_ of the speed.

At 23:44 07 August 2008, Mark Drela wrote:
In article , "user" writes:

Nontheless, the rudder balances aileron drag.

To be more precise, the rudder primarily balances the fore/aft
tilting of the lift vectors on the left and right wings,
which is a result of _roll rate_. The aileron drag difference
has a much smaller contribution.
The PDF diagram in this link illustrates the effect:
http://www.rcgroups.com/forums/showp...0&postcount=31


No sure that the above is the complete answer as it covers profile drag
but completely ignores induced (lift dependent) drag.

Consider a glider wing in level flight and assume we have a drag factor of
2 (Newtons, foot pounds,bananas, doesn't matter)
The airlerons to roll and the lift on the down going aileron wing is
doubled over the area influenced by the aileron, the induced drag
increases by 4. If the ailerons are non differential the lift over the
same area on the opposite wing is reduced by half to 1 giving a total
force of 5 trying to induce yaw. On a glider with long wings the leverage
of these forces will produce a significant adverse yaw while the aileron
is applied. I would agree that when the glider starts to roll the upgoing
wing suffers a reduced angle of attack, over it's whole area, reducing
the lift and vice versa for the other wing, these forces tending to
mitigate the adverse yaw caused by lift inbalance between the two wings.

Hi Mark,

On 07 Aug 2008 23:44:00 GMT, (Mark Drela) wrote:

In article , "user" writes:

Nontheless, the rudder balances aileron drag.

To be more precise, the rudder primarily balances the fore/aft
tilting of the lift vectors on the left and right wings,
which is a result of _roll rate_. The aileron drag difference
has a much smaller contribution.

Flying an open class glider with pretty limited roll rate, I can
assure you that roll rate does NOT influence adverse yaw at all.

As Don Johnstone already pointed out, adverse yaw is caused mainly by
induced drag.


Bye
Andreas

Hi Guys, I am a bit new to this forum, but see that you have quite a
prolonged discussion going on !

The only comment I would like to make is that whilst undergoing some type
conversion at the Long-Myndd, my Instructor said I was not using much
rudder.... Whilst I was flying straight and level...

My attempts at wing leveling where being quite succesful in the turbulent
air, and we were holding a good fixed heading, but he was correct; That
even without any roll, the deflected ailerons would still be producing
differential drag.... and the adverse yaw.

Many thanks to that Instructor, I now always use the rudder whenever I
shift the stick, even in straight and level flight.

Pilot Pete