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View Full Version : Leading Turns with Rudder - Revisited


Roy Clark, \B6\
August 4th 08, 04:29 PM
At the beginning, Paul wrote:
<An SSA 'Master' CFIG I know is perpetually hammering it into his
<students that to initiate a turn in a glider, 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 it's own separate input). While this may be aerodynamically
>acceptable practice for a 2-33, it seems a recipie for disaster in
>other ships to begin a turn by intentionally skidding. Since in a
>pinch, one has a tendency to revert to instincts that were first
>learned/practiced (right OR wrong), I see this as a setup for possible
>future problems.
>Since I have issues with this, I want to gather some other opinions
>(particularly those of other CFI's) to help present a case to
>possibly get this corrected. He holds little value of MYopinion, so I
<was hoping to get some 'name brand' opinions to help my case. And if
I
<am just putting to much into this, I would rather hear it from this
>group.

Paul,

I share your concerns about this. Not a CFIG, but I was not taught
this way of turning and none of the CFIG’s on multiple BFRs or check-
out flights in the USA – WA (4 different sites), AZ (2), CA (6), NV
(2), NM, CO, FL, PA, MD - or elsewhere, Canada (2); Germany; or
England (2) suggested his method.

So, I checked my home soaring library and found the following that
includes some ‘name brand’ opinions:

“For most beginners, making a turn is the most difficult step in
learning to fly. Two controls have to be operated together to perform
the evolution correctly. The rudder bar must be pushed back and the
stick tilted over. These movements must be made in coordination if the
glider is to be banked and turned at the same time.”
- Edwin Way Teale, The Book of Gliders, page 205, 1930

"Think it through. The turn is to be to the left. Apply the bank to
the wings with the stick, a gentle pressure in that direction. At the
same time apply a little left rudder. Don’t kick it, apply pressure.
These two movements are simultaneous. It’s like the arm motion and
foot work in tennis. If the timing of one or the other is off, it’s
the fence the ball goes over, not only the net."
- Richard A. Wolters, The Art and Technique of Soaring, page 80, 1971

“Unfortunately, this turn-by-rudder idea is hard to kill. It has away
of re-creating itself. It is often used to explain the airplane’s
controls to high school kids or general magazine readers—simply
because it is easy to understand for nonflying writers and readers,
teachers and pupils. It recreates itself also in the pilot’s own
nervous system, even when after he should really know better. This is
because you can use the rudder with apparent success to “steer” the
airplane, that is, to make small changes of direction, in straight
wings-level flight. As explained elsewhere, this is a faulty technique
of flying straight, but it is widely practiced, and if you use you
rudder 30 times a minute to steer the airplane a little bit more to
the right and a little bit more to the left, you are bound to use it
also when you want to steer he airplane a whole lot to the right and a
whole lot to the right and a whole lot to the left!
But the rudder can never produce a turn. It cannot “start” a turn or
even “help the turn get started.” It cannot “stop” a turn or even
“help the turn get stopped. The only effect the rudder can ever
produce is yaw. Yaw, in this sense, means practically the same as
“skid” or “slip.” The airplane’s nose is swung to one side or another
while the flight path continues substantially unchanged, so that the
airplane slices through the air slightly sideways. Yaw is not a turn.
A turn, a clean nice curving of the flight path without skid or slip,
cannot be produced by the rudder but is produced by entirely different
means. The rudder is quite unnecessary for the turn. Some airplanes
haven’t even got a rudder, but only a rigid vertical fin, and yet they
turn. And the birds don’t even have a vertical fin!
All this will be made clear to a patient reader. But first we must
kill the turn-by-rudder idea. Only when that is done can the reader’s
mind be really receptive to the story of how the airplane really does
turn.”
- Wolfgang Langewiesche, Stick and Rudder: An Explanation of the Art
of
Flying, pages 192-3, 1944

“Now that the turn and its forces are understood, the student should
be shown by applying pressure to both the stick (aileron) and rudder
in the same direction.”
- Schweizer Soaring School Manual, Revised Edition, page 26, 1982
[Would
apply to that 2-33.]

"To enter a turn:
1. ….
2. ….
3. While watching the horizon, apply stick and rudder together in the
desired direction."
-Thomas L. Knauff, Glider Basics: From First Flight to Solo, 4th Ed.,
page 52, 1987

“Assume that a turn to the left is to be made. The bank in that
direction is started with left stick and left rudder together.”
- Carle Conway, The Joy of Soaring, page 17, 1989

"Roll into the turn with aileron and, at the same time, use sufficient
in-turn rudder to prevent adverse yaw and any slip."
- Derek P.W. Johnson, The Glider Instructor’s Workbook, page 21, 1993

"Going into the turn
Before turning to the right, for example, first look out to the left
and then round as far as possible in the direction of the turn –
particularly behind the wing.
If it is clear then –
- look ahead over the nose
- roll the glider using aileron and stick together"
- British Gliding Association Instructor’s Manual, 10:2 1994

"Entering the turn
Lookout.
Look over the nose of the glider to check the glider’s attitude and
and bank angle.
Apply bank by using aileron and rudder together."
- Ken Stewart, The Glider Pilot’s Manual, page 46, 1994

"Going into a turn
1. Look around for other aircraft.
2. Look ahead and hold nose in correct attitude.
3. Apply the bank – move stick and rudder together"
- Derek Piggott, Beginning Gliding, 2nd Ed., page 42, 1995

"After release from tow, your instructor will demonstrate adverse yaw
by using ailerons to bank the glider without applying simultaneous
rudder. The glider with yaw in the opposite direction from the
intended turn at first. You instructor will then demonstrate use of
the rudder in coordination with the ailerons to counteract adverse
yaw."
-Bob Wander, Learning to Fly Gliders: A Flight Training Handbook and
Syllabus,
page 19, 2003

"It is important rudder and aileron inputs are coordinated during a
turn so maximum glider performance can be maintained. If too little
rudder is applied or if rudder is applied too late, the result will be
a slip. Too much rudder or rudder applied before aileron results is a
skid. Both skids and slips swing the fuselage of the glider into the
relative wind, creating additional parasite drag, which reduces lift
and airspeed. Although this increased drag caused by a slip can be
useful during approach to landing to steepen the approach path and
counteract a crosswind, it decreases glider performance during other
phases of flight."
- U.S. Department of Transportation, Federal Aviation Administration,
Glider Flying Handbook, page 3-12, 2003

Seems pretty consistent from 1930 to 2003 with the method I was
taught.

Perhaps that SSA ‘Master’ CFI has stronger soaring literature
documentation than the above to support his opinion. Were one of his
pupils involved in an injury incident, I’m quite sure he would need
it.

Jim White[_2_]
August 4th 08, 04:55 PM
This thread is boring...what's the lowest heigght one should start an
aerobatic manoeuvre? Should one use the rudder when rolling in a clover
leaf loop below 500ft?

Jim


At 15:29 04 August 2008, Roy Clark, \B6\ wrote:
>At the beginning, Paul wrote:
>is feed in rudder. On his 1-5 list of making a turn in a glider, #1 is
>>rudder (as it's own separate input). While this may be aerodynamically
>>acceptable practice for a 2-33, it seems a recipie for disaster in
>>other ships to begin a turn by intentionally skidding. Since in a
>>pinch, one has a tendency to revert to instincts that were first
>>learned/practiced (right OR wrong), I see this as a setup for possible
>>future problems.
>>Since I have issues with this, I want to gather some other opinions
>>(particularly those of other CFI's) to help present a case to
>>possibly get this corrected. He holds little value of MYopinion, so I
>group.
>
>Paul,
>
>I share your concerns about this. Not a CFIG, but I was not taught
>this way of turning and none of the CFIG=92s on multiple BFRs or check-
>out flights in the USA =96 WA (4 different sites), AZ (2), CA (6), NV
>(2), NM, CO, FL, PA, MD - or elsewhere, Canada (2); Germany; or
>England (2) suggested his method.
>
>So, I checked my home soaring library and found the following that
>includes some =91name brand=92 opinions:
>
>=93For most beginners, making a turn is the most difficult step in
>learning to fly. Two controls have to be operated together to perform
>the evolution correctly. The rudder bar must be pushed back and the
>stick tilted over. These movements must be made in coordination if the
>glider is to be banked and turned at the same time.=94
>- Edwin Way Teale, The Book of Gliders, page 205, 1930
>
>"Think it through. The turn is to be to the left. Apply the bank to
>the wings with the stick, a gentle pressure in that direction. At the
>same time apply a little left rudder. Don=92t kick it, apply pressure.
>These two movements are simultaneous. It=92s like the arm motion and
>foot work in tennis. If the timing of one or the other is off, it=92s
>the fence the ball goes over, not only the net."
>- Richard A. Wolters, The Art and Technique of Soaring, page 80, 1971
>
>=93Unfortunately, this turn-by-rudder idea is hard to kill. It has away
>of re-creating itself. It is often used to explain the airplane=92s
>controls to high school kids or general magazine readers=97simply
>because it is easy to understand for nonflying writers and readers,
>teachers and pupils. It recreates itself also in the pilot=92s own
>nervous system, even when after he should really know better. This is
>because you can use the rudder with apparent success to =93steer=94 the
>airplane, that is, to make small changes of direction, in straight
>wings-level flight. As explained elsewhere, this is a faulty technique
>of flying straight, but it is widely practiced, and if you use you
>rudder 30 times a minute to steer the airplane a little bit more to
>the right and a little bit more to the left, you are bound to use it
>also when you want to steer he airplane a whole lot to the right and a
>whole lot to the right and a whole lot to the left!
> But the rudder can never produce a turn. It cannot =93start=94 a turn
or
>even =93help the turn get started.=94 It cannot =93stop=94 a turn or
even
>=93help the turn get stopped. The only effect the rudder can ever
>produce is yaw. Yaw, in this sense, means practically the same as
>=93skid=94 or =93slip.=94 The airplane=92s nose is swung to one side or
>ano=
>ther
>while the flight path continues substantially unchanged, so that the
>airplane slices through the air slightly sideways. Yaw is not a turn.
>A turn, a clean nice curving of the flight path without skid or slip,
>cannot be produced by the rudder but is produced by entirely different
>means. The rudder is quite unnecessary for the turn. Some airplanes
>haven=92t even got a rudder, but only a rigid vertical fin, and yet they
>turn. And the birds don=92t even have a vertical fin!
> All this will be made clear to a patient reader. But first we must
>kill the turn-by-rudder idea. Only when that is done can the reader=92s
>mind be really receptive to the story of how the airplane really does
>turn.=94
>- Wolfgang Langewiesche, Stick and Rudder: An Explanation of the Art
>of
> Flying, pages 192-3, 1944
>
>=93Now that the turn and its forces are understood, the student should
>be shown by applying pressure to both the stick (aileron) and rudder
>in the same direction.=94
>- Schweizer Soaring School Manual, Revised Edition, page 26, 1982
>[Would
>apply to that 2-33.]
>
>"To enter a turn:
>1. =85.
>2. =85.
>3. While watching the horizon, apply stick and rudder together in the
>desired direction."
>-Thomas L. Knauff, Glider Basics: From First Flight to Solo, 4th Ed.,
>page 52, 1987
>
>=93Assume that a turn to the left is to be made. The bank in that
>direction is started with left stick and left rudder together.=94
>- Carle Conway, The Joy of Soaring, page 17, 1989
>
>"Roll into the turn with aileron and, at the same time, use sufficient
>in-turn rudder to prevent adverse yaw and any slip."
>- Derek P.W. Johnson, The Glider Instructor=92s Workbook, page 21, 1993
>
>"Going into the turn
>Before turning to the right, for example, first look out to the left
>and then round as far as possible in the direction of the turn =96
>particularly behind the wing.
>If it is clear then =96
>- look ahead over the nose
>- roll the glider using aileron and stick together"
>- British Gliding Association Instructor=92s Manual, 10:2 1994
>
>"Entering the turn
>Lookout.
>Look over the nose of the glider to check the glider=92s attitude and
>and bank angle.
>Apply bank by using aileron and rudder together."
>- Ken Stewart, The Glider Pilot=92s Manual, page 46, 1994
>
>"Going into a turn
>1. Look around for other aircraft.
>2. Look ahead and hold nose in correct attitude.
>3. Apply the bank =96 move stick and rudder together"
>- Derek Piggott, Beginning Gliding, 2nd Ed., page 42, 1995
>
>"After release from tow, your instructor will demonstrate adverse yaw
>by using ailerons to bank the glider without applying simultaneous
>rudder. The glider with yaw in the opposite direction from the
>intended turn at first. You instructor will then demonstrate use of
>the rudder in coordination with the ailerons to counteract adverse
>yaw."
> -Bob Wander, Learning to Fly Gliders: A Flight Training Handbook and
>Syllabus,
> page 19, 2003
>
>"It is important rudder and aileron inputs are coordinated during a
>turn so maximum glider performance can be maintained. If too little
>rudder is applied or if rudder is applied too late, the result will be
>a slip. Too much rudder or rudder applied before aileron results is a
>skid. Both skids and slips swing the fuselage of the glider into the
>relative wind, creating additional parasite drag, which reduces lift
>and airspeed. Although this increased drag caused by a slip can be
>useful during approach to landing to steepen the approach path and
>counteract a crosswind, it decreases glider performance during other
>phases of flight."
>- U.S. Department of Transportation, Federal Aviation Administration,
>Glider Flying Handbook, page 3-12, 2003
>
>Seems pretty consistent from 1930 to 2003 with the method I was
>taught.
>
>Perhaps that SSA =91Master=92 CFI has stronger soaring literature
>documentation than the above to support his opinion. Were one of his
>pupils involved in an injury incident, I=92m quite sure he would need
>it.
>
>
>
>
>

Roy Clark, \B6\
August 5th 08, 02:32 AM
On Aug 4, 8:55*am, Jim White > wrote:
> This thread is boring...what's the lowest heigght one should start an
> aerobatic manoeuvre?

In the US FAR 91.119 Minimum safe altitudes: General
(b) Over congested areas ... [no lower than] an altitude of 1,000 feet
above the highest obstacle within a horizontal radius of 2,000 feet of
the aircraft.
(c) Over than other congested areas .... an altutude of 500 feet above
the surface, except over open water or sparsely populated areas. In
those cases, the aircraft may not be operated closer than 500 feet to
any person, vessel, vehicle, or structure.

>Should one use the rudder when rolling in a clover
> leaf loop below 500ft?

Yes, at the same time as the ailerons - your choice of any one of
those "boring" citations.

Go for it, Dude!

Tony Verhulst
August 5th 08, 03:04 AM
> In the US FAR 91.119 Minimum safe altitudes: General....
> [no lower than] an altitude of 1,000 feet

Nah.

§ 91.303 Aerobatic flight.

No person may operate an aircraft in aerobatic flight—
<< snipped for brevity >>
(e) Below an altitude of 1,500 feet above the surface; or

Tony V.

Darryl Ramm
August 5th 08, 03:23 AM
On Aug 4, 7:04*pm, Tony Verhulst > wrote:
> > In the US FAR 91.119 Minimum safe altitudes: General....
> > [no lower than] an altitude of 1,000 feet
>
> Nah.
>
> § 91.303 * Aerobatic flight.
>
> No person may operate an aircraft in aerobatic flight—
> << snipped for brevity >>
> (e) Below an altitude of 1,500 feet above the surface; or
>
> Tony V.

What worries me more is doing the cloverleaf with all those damn books
flying around in the cockpit.

Darryl

bumper
August 5th 08, 05:05 AM
"Jim White" > wrote in message
...
> This thread is boring...what's the lowest heigght one should start an
> aerobatic manoeuvre? Should one use the rudder when rolling in a clover
> leaf loop below 500ft?
>
> Jim


Silly FARs and nonsensical regulations about minimum height for aerobatics
notwithstanding, be sure to get this on video for YouTube. Even without the
Darryl's books flying about the cockpit, you may be assured it won't be
boring.

bumper

J a c k
August 7th 08, 05:16 PM
Jim White wrote:


> ...what's the lowest height one should start an
> aerobatic manoeuvre?



How low do you want to recover?



Jack

Jim White[_2_]
August 7th 08, 06:25 PM
At 16:16 07 August 2008, J a c k wrote:
>Jim White wrote:
>
>
>> ...what's the lowest height one should start an
>> aerobatic manoeuvre?
>
>
>
>How low do you want to recover?
>
>
>
>Jack
>
>
>
Above ground
Jim

Shawn[_6_]
August 7th 08, 06:36 PM
Jim White wrote:
> At 16:16 07 August 2008, J a c k wrote:
>> Jim White wrote:
>>
>>
>>> ...what's the lowest height one should start an
>>> aerobatic manoeuvre?
>>
>>
>> How low do you want to recover?
>>
>>
>>
>> Jack
>>
>>
>>
> Above ground
> Jim

How low do you want to recover if a Fed is watching. :-)



Shawn

Jim White[_2_]
August 7th 08, 09:40 PM
At 17:36 07 August 2008, Shawn wrote:
>Jim White wrote:
>> At 16:16 07 August 2008, J a c k wrote:
>>> Jim White wrote:
>>>
>>>
>>>> ...what's the lowest height one should start an
>>>> aerobatic manoeuvre?
>>>
>>>
>>> How low do you want to recover?
>>>
>>>
>>>
>>> Jack
>>>
>>>
>>>
>> Above ground
>> Jim
>
>How low do you want to recover if a Fed is watching. :-)
>
>
>
>Shawn
>
Behind a hill or a hedge

Jim

Don Johnstone[_3_]
August 7th 08, 10:40 PM
At 20:40 07 August 2008, Jim White wrote:
>At 17:36 07 August 2008, Shawn wrote:
>>Jim White wrote:
>>> At 16:16 07 August 2008, J a c k wrote:
>>>> Jim White wrote:
>>>>
>>>>
>>>>> ...what's the lowest height one should start an
>>>>> aerobatic manoeuvre?
>>>>
>>>>
>>>> How low do you want to recover?
>>>>
>>>>
>>>>
>>>> Jack
>>>>
>>>>
>>>>
>>> Above ground
>>> Jim
>>
>>How low do you want to recover if a Fed is watching. :-)
>>
>>
>>
>>Shawn
>>
>Behind a hill or a hedge
>
>Jim

I would give up if I were you chaps, his replies are about as accurate and
truthful as a 9 bob watch (that's Brit speak for very cheap) :-)

Eric Greenwell
August 12th 08, 06:00 AM
Roy Clark, "B6" wrote:
> So, I checked my home soaring library and found the following that
> includes some ‘name brand’ opinions:
>
> “For most beginners, making a turn is the most difficult step in
> learning to fly. Two controls have to be operated together to perform
> the evolution correctly. The rudder bar must be pushed back and the
> stick tilted over. These movements must be made in coordination if the
> glider is to be banked and turned at the same time.”
> - Edwin Way Teale, The Book of Gliders, page 205, 1930

I agree with the statement above.

> But the rudder can never produce a turn. It cannot “start” a turn or
> even “help the turn get started.” It cannot “stop” a turn or even
> “help the turn get stopped. The only effect the rudder can ever
> produce is yaw.

some snipping.

> - Wolfgang Langewiesche, Stick and Rudder: An Explanation of the Art
> of
> Flying, pages 192-3, 1944

I don't have the full context from the quote above, and while I am
normally loathe to contradict Langewiesche, I must report I have
successfully produced turns with just the rudder in gliders. Give it a
try, and you will find you can produce an adequate turn, because the
yawing causes the dihedral to bank the glider in the desired direction.
At thermalling speeds, the turn isn't entered as quickly or as neatly,
but it happens. The higher the speed, the better the rudder works to
turn the glider.

There is a situation where the rudder does a good job of turning the
glider, and that's when it's rolling fast on the ground. Doing a
"coordinated" turn, where you also use the ailerons, is going to get you
into trouble.

As an instructor, I discovered the emphasis on "coordinated turns" and
telling students "the rudder doesn't turn the glider" led to good
airwork but caused problems while rolling on the ground. I stopped
talking about WHAT turned the glider and started talking about each
controls primary function, and what you wanted to see through the canopy
when you did turns. I'd demonstrate the action of each control, and show
them what a good turn looked like, then let them try it themselves. I
emphasized using the controls to obtain/maintain the desired "picture"
(attitude) out of the canopy.

In the air, they very quickly learned to use the rudder to keep the nose
from yawing as they rolled into the turn. I didn't have to tell them
when to apply rudder or how much to use, as they could see for
themselves when the nose didn't move in the right direction, and correct
it. After some practice, it became automatic, and when they were too
early/late or too much/little with any control, they could recognize the
error and know which control was misapplied.

On the ground, they no longer had problems slavishly trying to
"coordinate", as they continued to use the ailerons to keep the wings in
the desired attitude and used the rudder to keep the nose pointed in the
desired direction.

So, I suggest we stop telling people "the rudder doesn't turn the
glider" because the statement is false, and tell them the truth: we use
the rudder to turn the glider on the ground, and in the air we use the
ailerons, rudder, and elevator to turn the glider.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

* Updated! "Transponders in Sailplanes" http://tinyurl.com/y739x4
* New Jan '08 - sections on Mode S, TPAS, ADS-B, Flarm, more

* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

John Wright
August 12th 08, 10:10 AM
At 05:00 12 August 2008, Eric Greenwell wrote:
>Roy Clark, "B6" wrote:
snipped

>I don't have the full context from the quote above, and while I am
>normally loathe to contradict Langewiesche, I must report I have
>successfully produced turns with just the rudder in gliders. Give it a
>try, and you will find you can produce an adequate turn, because the
>yawing causes the dihedral to bank the glider in the desired direction.

I suggest you give it a try at or near the stall...

(Only in america would we come across such a technique even being
discussed!)

Darryl Ramm
August 12th 08, 10:42 AM
On Aug 12, 2:10*am, John Wright > wrote:
> At 05:00 12 August 2008, Eric Greenwell wrote:>Roy Clark, "B6" wrote:
>
> snipped
>
> >I don't have the full context from the quote above, and while I am
> >normally loathe to contradict Langewiesche, I must report I have
> >successfully produced turns with just the rudder in gliders. Give it a
> >try, and you will find you can produce an adequate turn, because the
> >yawing causes the dihedral to bank the glider in the desired direction.
>
> I suggest you give it a try at or near the stall...
>
> (Only in america would we come across such a technique even being
> discussed!)

What it might stall/spin? Wow nobody would have known that. Thanks so
much for sharing.

Can we give this crap a rest? We all get the stall/spin issue. The
comment was if you stand on the rudder alone a glider will turn. Do
you really think that was being advocated as a method to use?

Darryl

bagmaker
August 12th 08, 11:33 AM
I don't have the full context from the quote above, and while I am
normally loathe to contradict Langewiesche, I must report I have
successfully produced turns with just the rudder in gliders. Give it a
try, and you will find you can produce an adequate turn, because the
yawing causes the dihedral to bank the glider in the desired direction.

I suggest you give it a try at or near the stall...

(Only in america would we come across such a technique even being
discussed!)

And only on the world wide web would an American assume they were the extent of the actual world.

Bagger
winter in Aus-bloody-stralia mate
:-)

Martin Gregorie[_4_]
August 12th 08, 11:58 AM
On Tue, 12 Aug 2008 02:42:16 -0700, Darryl Ramm wrote:

> The
> comment was if you stand on the rudder alone a glider will turn. Do you
> really think that was being advocated as a method to use?
>
No, but it is a useful reminder of the way some aircraft react.

I've always known that was possible to turn using just the rudder GIVEN
THE RIGHT AIRFRAME, because otherwise it would be impossible to fly an RC
model that lacks ailerons: I flew single channel rudder-only models when
I was a lad.

Eric specified it exactly right: to turn an aircraft using just the
rudder requires it to have fairly generous dihedral. The yaw induces a
turn as a secondary effect because dihedral increases the effective AOA
of the advancing wing while reducing it for the retreating one. If the
aircraft has little or no dihedral this secondary effect can be ignored.

All rudder only or rudder & elevator RC models have generous amounts of
dihedral.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

Don Johnstone[_3_]
August 12th 08, 12:40 PM
The further effect of rudder is ????????????

Of course that works but the original point of this whole thread was the
use of rudder slightly before airleron to overcome inertia (prevent the
adverse yaw) I think most agree it is a valid technique for experienced
pilots, who understand the problems, in some gliders.
It is NOT to be taught to ab initio students. They should be using less
aileron anyway so would not have to overcome the problem. It is only large
inputs of aileron in certain gliders where there is a problem.



At 10:58 12 August 2008, Martin Gregorie wrote:
>On Tue, 12 Aug 2008 02:42:16 -0700, Darryl Ramm wrote:
>
>> The
>> comment was if you stand on the rudder alone a glider will turn. Do
you
>> really think that was being advocated as a method to use?
>>
>No, but it is a useful reminder of the way some aircraft react.
>
>I've always known that was possible to turn using just the rudder GIVEN

>THE RIGHT AIRFRAME, because otherwise it would be impossible to fly an RC

>model that lacks ailerons: I flew single channel rudder-only models when

>I was a lad.
>
>Eric specified it exactly right: to turn an aircraft using just the
>rudder requires it to have fairly generous dihedral. The yaw induces a
>turn as a secondary effect because dihedral increases the effective AOA
>of the advancing wing while reducing it for the retreating one. If the
>aircraft has little or no dihedral this secondary effect can be ignored.
>
>All rudder only or rudder & elevator RC models have generous amounts of
>dihedral.
>
>
>--
>martin@ | Martin Gregorie
>gregorie. | Essex, UK
>org |
>

Jim Beckman[_2_]
August 12th 08, 03:10 PM
At 09:10 12 August 2008, John Wright wrote:
>
>>I don't have the full context from the quote above, and while I am
>>normally loathe to contradict Langewiesche, I must report I have
>>successfully produced turns with just the rudder in gliders. Give it a
>>try, and you will find you can produce an adequate turn, because the
>>yawing causes the dihedral to bank the glider in the desired direction.

>
>I suggest you give it a try at or near the stall...
>
>(Only in america would we come across such a technique even being
>discussed!)

So what would you do if your aileron's became disconnected
from the control stick in flight? Interesting problem, right?

It happened to a partner of mine several years ago, in
his 1-26. Exactly how is a bit of a mystery, but using one
safety pin for both control pins was certainly a contributing
factor, and he doesn't do that anymore.

Anyway, what would you have done? He proceeded just as
outlined in the double-indented comment above, flew a wide
pattern and landed successfully back at home base. Of
course, the fact that he was dealing with a 1-26 made the
task somewhat easier than it might have been.

Jim Beckman

John Smith
August 12th 08, 03:53 PM
>> “For most beginners, making a turn is the most difficult step in
>> learning to fly. Two controls have to be operated together to perform
>> the evolution correctly. The rudder bar must be pushed back and the
>> stick tilted over...

> I agree with the statement above.

I don't, because it is twofold wrong.

First, not two controls must be operated together, but all three.

Second, it is not the most difficult step in learning to fly. It is only
difficult if the instructor tells the student that it is difficult makes
a big fuss about it. If however you show he student with some kind of
aircraft model (your hands may be adequate) that the aircraft must turn
around all three axes, then this will be the most natural thing for the
student. Just be sure that you mention adverse yaw and such esotheric
things only after the student has mastered to make perfect turns.

Michael Ash
August 12th 08, 04:22 PM
Jim Beckman > wrote:
> It happened to a partner of mine several years ago, in
> his 1-26. Exactly how is a bit of a mystery, but using one
> safety pin for both control pins was certainly a contributing
> factor, and he doesn't do that anymore.

Could you elaborate on why that was a contributing factor? Is it just the
fact that if you forget a single safety pin, you lose both ailerons?

--
Mike Ash
Radio Free Earth
Broadcasting from our climate-controlled studios deep inside the Moon

PMSC Member
August 12th 08, 05:36 PM
On Aug 12, 6:33 am, bagmaker >
wrote:
> -
> I don't have the full context from the quote above, and while I am
> normally loathe to contradict Langewiesche, I must report I have
> successfully produced turns with just the rudder in gliders. Give it a
>
> try, and you will find you can produce an adequate turn, because the
> yawing causes the dihedral to bank the glider in the desired direction.
>
> I suggest you give it a try at or near the stall...
>
> (Only in america would we come across such a technique even being
> discussed!)-
>
> And only on the world wide web would an American assume they were the
> extent of the actual world.
>
> Bagger
> winter in Aus-bloody-stralia mate
> :-)
>
> --
> bagmaker

Come now. The author of very silly comment you refer to has a .uk
address.

Nyal Williams[_2_]
August 12th 08, 07:55 PM
I have observed that none of the well-known, noted, and outstanding
instructors are posting to this thread. That fact qualifies me to post.

Frequently during a Biennial Flight Review I will ask a pilot to produce a
turn and then stop it with ailerons only (I lock the rudder bar with my
feet) and to observe what happens to the nose and to the yaw string.
(Plenty of altitude and at about 50kts airspeed) Then I ask the pilot to
produce a turn and then stop it with rudder only (I prevent aileron
movement). Then I ask the pilot if he could have just one of these
controls on final, which would be the choice. The answer is always
"Rudder."

Actually, neither of these controls produce the turn. After the aircraft
is banked, the elevator causes the turn by ncreasing the angle of attack.
If you doubt this, ease the stick forward a bit the next time you start a
turn. This is how aerobatic pilots fly down straight down the runway
banked at least 45 degrees (and with some top rudder to hold the nose up.

Doing an adequate turn is easy enough; doing a perfect turn is not so
easy. I sometimes tell students that I did a perfect one in 1957 and am
hoping to do another one soon so that I will know it was not an accident.
(Read Langewiesche's description of a perfect turn very carefully to see
whether your performance matches it.)

At 14:10 12 August 2008, Jim Beckman wrote:
>At 09:10 12 August 2008, John Wright wrote:
>>
>>>I don't have the full context from the quote above, and while I am
>>>normally loathe to contradict Langewiesche, I must report I have
>>>successfully produced turns with just the rudder in gliders. Give it a

>>>try, and you will find you can produce an adequate turn, because the
>>>yawing causes the dihedral to bank the glider in the desired
direction.
>
>>
>>I suggest you give it a try at or near the stall...
>>
>>(Only in america would we come across such a technique even being
>>discussed!)
>
>So what would you do if your aileron's became disconnected
>from the control stick in flight? Interesting problem, right?
>
>It happened to a partner of mine several years ago, in
>his 1-26. Exactly how is a bit of a mystery, but using one
>safety pin for both control pins was certainly a contributing
>factor, and he doesn't do that anymore.
>
>Anyway, what would you have done? He proceeded just as
>outlined in the double-indented comment above, flew a wide
>pattern and landed successfully back at home base. Of
>course, the fact that he was dealing with a 1-26 made the
>task somewhat easier than it might have been.
>
>Jim Beckman
>
>

Jim Beckman[_2_]
August 12th 08, 07:55 PM
At 15:22 12 August 2008, Michael Ash wrote:
>Jim Beckman wrote:
>> It happened to a partner of mine several years ago, in
>> his 1-26. Exactly how is a bit of a mystery, but using one
>> safety pin for both control pins was certainly a contributing
>> factor, and he doesn't do that anymore.
>
>Could you elaborate on why that was a contributing factor? Is it just the

>fact that if you forget a single safety pin, you lose both ailerons?

Well, the safety pin couldn't be found in the glider after
the flight. The safety pin had to fail, somehow, before
the control pins could fall out (which they did, one at a
time). Seems to me that using one safety pin instead of
two means you only need one failure to lose both ailerons.
Better to put two failure requirements in the path.

BTW, while he still had one aileron functioning, he found
the glider to be controllable, but sluggish. Not bad enough
that he realized what had happened, though, until the
other aileron disconnected.

Oh, another point to clarify the situation - the glider had
*not* been disassembled before the failure. I don't know
how good his pre-flight was, I generally reach back over
the seat and feel for the pins and safety pins. With a
transparent turtle deck on this glider, you can also check
visually.

Jim Beckman

Martin Gregorie[_4_]
August 12th 08, 08:14 PM
On Tue, 12 Aug 2008 11:40:14 +0000, Don Johnstone wrote:

> The further effect of rudder is ????????????
>
My point was to emphasise that whether a glider can be ruddered round or
not depends on the airframe, not to continue the discussion about the
right way to turn a glider.

Libelles, which have noticeable dihedral, can be gently steered with
rudder alone while a nearly flat wing, such as a Junior, will tend to fly
sideways rather than turn.

I think this is useful stuff to know for the same reason that its nice to
know that you can fly gentle aileron-only turns in, say, an ASK-21. If
you lose control over one axis for some reason, then knowing how to
compensate may just save your life. However it would surprise me if all
gliders react the same to uncoordinated turns, so trying aileron-only and
rudder-only turns at a safe height could be a worthwhile exercise for any
owner.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

Eric Greenwell
August 12th 08, 09:09 PM
bagmaker wrote:
> -
> I don't have the full context from the quote above, and while I am
> normally loathe to contradict Langewiesche, I must report I have
> successfully produced turns with just the rudder in gliders. Give it a
>
> try, and you will find you can produce an adequate turn, because the
> yawing causes the dihedral to bank the glider in the desired direction.
>
>
> I suggest you give it a try at or near the stall...

I've not done it myself, but I've read about how attempting a
coordinated turn at or near stall can cause an "over the top" spin entry
when the out-of-turn aileron is deflected downward and stalls the outer
wing tip. In any case, my experience (and the text books) indicates that
an attempt to turn at or near a stall risks entering into a spin, even
with "proper" use of the controls. The pilot should speed up before
attempting the turn, coordinated or not.

This reminds me of another frequently repeated statement: "you won't
spin if you keep the yaw string centered." Besides my amazing ability to
turn a glider with just the rudder, I also have the ability to enter a
spin from a coordinated turn! I've done it in our club's Blanik and my
current glider, and I think it works on most gliders. Here's my secret:

*enter a coordinated, shallow (say, about 10 degree bank) turn
*reduce the airspeed slowly while keeping the yaw string straight
*at some point, the inner wing will drop, and the spin begins (it might
be spiral dive with some gliders)
*recover in the usual fashion when desired (I prefer to do it sooner
than later)

Of course, the glider's attitude is nose high, along with other warning
signs that the pilot is not doing things right. Still, I wonder how many
pilots unintentionally flew too slowly, but thought they were safe
because the yaw string was centered.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

* Updated! "Transponders in Sailplanes" http://tinyurl.com/y739x4
* New Jan '08 - sections on Mode S, TPAS, ADS-B, Flarm, more

* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

Eric Greenwell
August 12th 08, 09:27 PM
John Smith wrote:
>>> “For most beginners, making a turn is the most difficult step in
>>> learning to fly. Two controls have to be operated together to perform
>>> the evolution correctly. The rudder bar must be pushed back and the
>>> stick tilted over...
>
>> I agree with the statement above.
>
> I don't, because it is twofold wrong.

I typed in haste, as I've decided I don't agree with the statement,
either, especially the part about the turn being the most difficult
step. Learning to stay behind the towplane was the hardest part for my
students, and they learned it more quickly if they *did not* use
coordinated turns to keep in place.

Initially, I told them to keep the glider wings parallel to the towplane
wing, to use the rudder align the yaw string, and the elevator to keep
the towplane vertically centered on the "aim point" of the canopy. After
serveral tows and the "coordinated turn" practice during those flights,
they transitioned to using coordinated turns without any further
guidance on my part.

My experience was students learned most rapidly if they were shown what
the correct attitudes were (the picture out of the canopy) and how the
controls affected the attitude.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

* Updated! "Transponders in Sailplanes" http://tinyurl.com/y739x4
* New Jan '08 - sections on Mode S, TPAS, ADS-B, Flarm, more

* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

Nyal Williams[_2_]
August 12th 08, 09:40 PM
This is the situation in which having the yaw string slightly to the
outside is helpful; a slight amount of slip, which Dick Johnson
recommended for increasing climb.

At 20:09 12 August 2008, Eric Greenwell wrote:

>This reminds me of another frequently repeated statement: "you won't
>spin if you keep the yaw string centered." Besides my amazing ability to

>turn a glider with just the rudder, I also have the ability to enter a
>spin from a coordinated turn! I've done it in our club's Blanik and my

>current glider, and I think it works on most gliders. Here's my secret:
>
>*enter a coordinated, shallow (say, about 10 degree bank) turn
>*reduce the airspeed slowly while keeping the yaw string straight
>*at some point, the inner wing will drop, and the spin begins (it might
>be spiral dive with some gliders)
>*recover in the usual fashion when desired (I prefer to do it sooner
>than later)
>
>Of course, the glider's attitude is nose high, along with other warning

>signs that the pilot is not doing things right. Still, I wonder how many

>pilots unintentionally flew too slowly, but thought they were safe
>because the yaw string was centered.
>
>--
>Eric Greenwell - Washington State, USA
>* Change "netto" to "net" to email me directly
>
>* Updated! "Transponders in Sailplanes" http://tinyurl.com/y739x4
> * New Jan '08 - sections on Mode S, TPAS, ADS-B, Flarm, more
>
>* "A Guide to Self-launching Sailplane Operation" at
www.motorglider.org
>

Don Johnstone[_3_]
August 13th 08, 12:10 AM
A glider may stall at any attitude. If yaw is present or induced a spin
will result. If the aircraft is banked when a stall occurs the glider will
slip in the direction of the "down" wing and yaw will be induced = spin.

(1)The signs of an approaching stall in a glider are

Nose high attitude (not always)
Reduced airspeed (quieter) (not always)
Lack of effectiveness of controls
Buffet (sometimes masked)

Symtoms of the stall

(2)Nose pitches down (despite stick movement)
Heavy buffet
High rate of sink
Low or fluctuating airspeed

Nothing at all about yaw string.

In the example, given by Nyal below, if the glider stalls with slip it is
more likely that a spin will result.
Ignore 1 and you WILL move to 2. If any yaw is present autorotation will
start but on some gliders will stop without control input, mistakenly said
to be a glider which will not spin. On other gliders varying amounts of the
full spin recovery will be required.
On the instrument panel of a DH Chipmunk there is a placard which reads
"Full forward movement of the stick may be required to recover from a
spin" There is absolutely NO maybe about it, that is the other extreme.
The lack of skin on my right knuckles has got nothing to do with it
dragging on the ground.


At 20:40 12 August 2008, Nyal Williams wrote:
>This is the situation in which having the yaw string slightly to the
>outside is helpful; a slight amount of slip, which Dick Johnson
>recommended for increasing climb.
>
>At 20:09 12 August 2008, Eric Greenwell wrote:
>
>>This reminds me of another frequently repeated statement: "you won't
>>spin if you keep the yaw string centered." Besides my amazing ability
to
>
>>turn a glider with just the rudder, I also have the ability to enter a
>>spin from a coordinated turn! I've done it in our club's Blanik and
my
>
>>current glider, and I think it works on most gliders. Here's my
secret:
>>
>>*enter a coordinated, shallow (say, about 10 degree bank) turn
>>*reduce the airspeed slowly while keeping the yaw string straight
>>*at some point, the inner wing will drop, and the spin begins (it might

>>be spiral dive with some gliders)
>>*recover in the usual fashion when desired (I prefer to do it sooner
>>than later)
>>
>>Of course, the glider's attitude is nose high, along with other
warning
>
>>signs that the pilot is not doing things right. Still, I wonder how
many
>
>>pilots unintentionally flew too slowly, but thought they were safe
>>because the yaw string was centered.
>>
>>--
>>Eric Greenwell - Washington State, USA
>>* Change "netto" to "net" to email me directly
>>
>>* Updated! "Transponders in Sailplanes" http://tinyurl.com/y739x4
>> * New Jan '08 - sections on Mode S, TPAS, ADS-B, Flarm, more
>>
>>* "A Guide to Self-launching Sailplane Operation" at
>www.motorglider.org
>>
>

Michael Ash
August 13th 08, 12:49 AM
Jim Beckman > wrote:
> At 15:22 12 August 2008, Michael Ash wrote:
>>Jim Beckman wrote:
>>> It happened to a partner of mine several years ago, in
>>> his 1-26. Exactly how is a bit of a mystery, but using one
>>> safety pin for both control pins was certainly a contributing
>>> factor, and he doesn't do that anymore.
>>
>>Could you elaborate on why that was a contributing factor? Is it just the
>
>>fact that if you forget a single safety pin, you lose both ailerons?
>
> Well, the safety pin couldn't be found in the glider after
> the flight. The safety pin had to fail, somehow, before
> the control pins could fall out (which they did, one at a
> time). Seems to me that using one safety pin instead of
> two means you only need one failure to lose both ailerons.
> Better to put two failure requirements in the path.

Makes sense to me. Thanks.

--
Mike Ash
Radio Free Earth
Broadcasting from our climate-controlled studios deep inside the Moon

Nyal Williams[_2_]
August 13th 08, 12:55 AM
I agree with all you say. A slip makes a spin less likely, perhaps not
significantly so, but surely less likely than a skidded turn.

At 23:10 12 August 2008, Don Johnstone wrote:
>A glider may stall at any attitude. If yaw is present or induced a spin
>will result. If the aircraft is banked when a stall occurs the glider
will
>slip in the direction of the "down" wing and yaw will be induced =
spin.
>
>(1)The signs of an approaching stall in a glider are
>
>Nose high attitude (not always)
>Reduced airspeed (quieter) (not always)
>Lack of effectiveness of controls
>Buffet (sometimes masked)
>
>Symptoms of the stall
>
>(2)Nose pitches down (despite stick movement)
>Heavy buffet
>High rate of sink
>Low or fluctuating airspeed
>
>Nothing at all about yaw string.
>
>In the example, given by Nyal below, if the glider stalls with slip it
is
>more likely that a spin will result.
>Ignore 1 and you WILL move to 2. If any yaw is present autorotation will
>start but on some gliders will stop without control input, mistakenly
said
>to be a glider which will not spin. On other gliders varying amounts of
>the
>full spin recovery will be required.
>On the instrument panel of a DH Chipmunk there is a placard which reads
>"Full forward movement of the stick may be required to recover from a
>spin" There is absolutely NO maybe about it, that is the other extreme.
>The lack of skin on my right knuckles has got nothing to do with it
>dragging on the ground.
>
>
>At 20:40 12 August 2008, Nyal Williams wrote:
>>This is the situation in which having the yaw string slightly to the
>>outside is helpful; a slight amount of slip, which Dick Johnson
>>recommended for increasing climb.
>>
>>At 20:09 12 August 2008, Eric Greenwell wrote:
>>
>>>This reminds me of another frequently repeated statement: "you won't

>>>spin if you keep the yaw string centered." Besides my amazing ability
>to
>>
>>>turn a glider with just the rudder, I also have the ability to enter a

>>>spin from a coordinated turn! I've done it in our club's Blanik and
>my
>>
>>>current glider, and I think it works on most gliders. Here's my
>secret:
>>>
>>>*enter a coordinated, shallow (say, about 10 degree bank) turn
>>>*reduce the airspeed slowly while keeping the yaw string straight
>>>*at some point, the inner wing will drop, and the spin begins (it
might
>
>>>be spiral dive with some gliders)
>>>*recover in the usual fashion when desired (I prefer to do it sooner
>>>than later)
>>>
>>>Of course, the glider's attitude is nose high, along with other
>warning
>>
>>>signs that the pilot is not doing things right. Still, I wonder how
>many
>>
>>>pilots unintentionally flew too slowly, but thought they were safe
>>>because the yaw string was centered.
>>>
>>>--
>>>Eric Greenwell - Washington State, USA
>>>* Change "netto" to "net" to email me directly
>>>
>>>* Updated! "Transponders in Sailplanes" http://tinyurl.com/y739x4
>>> * New Jan '08 - sections on Mode S, TPAS, ADS-B, Flarm, more
>>>
>>>* "A Guide to Self-launching Sailplane Operation" at
>>www.motorglider.org
>>>
>>
>

Jim[_13_]
August 13th 08, 06:15 PM
On Tue, 12 Aug 2008 20:09:25 GMT, Eric Greenwell
> wrote:

>bagmaker wrote:
>> -
>> I don't have the full context from the quote above, and while I am
>> normally loathe to contradict Langewiesche, I must report I have
>> successfully produced turns with just the rudder in gliders. Give it a
>>
>> try, and you will find you can produce an adequate turn, because the
>> yawing causes the dihedral to bank the glider in the desired direction.
>>
>>
>> I suggest you give it a try at or near the stall...
>
>I've not done it myself, but I've read about how attempting a
>coordinated turn at or near stall can cause an "over the top" spin entry
>when the out-of-turn aileron is deflected downward and stalls the outer
>wing tip. In any case, my experience (and the text books) indicates that
>an attempt to turn at or near a stall risks entering into a spin, even
>with "proper" use of the controls. The pilot should speed up before
>attempting the turn, coordinated or not.
>
>This reminds me of another frequently repeated statement: "you won't
>spin if you keep the yaw string centered." Besides my amazing ability to
>turn a glider with just the rudder, I also have the ability to enter a
>spin from a coordinated turn! I've done it in our club's Blanik and my
>current glider, and I think it works on most gliders. Here's my secret:
>
>*enter a coordinated, shallow (say, about 10 degree bank) turn
>*reduce the airspeed slowly while keeping the yaw string straight
>*at some point, the inner wing will drop, and the spin begins (it might
>be spiral dive with some gliders)
>*recover in the usual fashion when desired (I prefer to do it sooner
>than later)
>
>Of course, the glider's attitude is nose high, along with other warning
>signs that the pilot is not doing things right. Still, I wonder how many
>pilots unintentionally flew too slowly, but thought they were safe
>because the yaw string was centered.

The understanding of just what a centered yaw string indicates is
something I have always struggled with.

After some thought experiments, and some flying experiments too,
I have come to my own realization that I must never assume that
a centered yaw string indicates anything about the angle of attack
occuring on the left and right wings.

In a coordinated turn, that is, a turn during which the yaw string
is centered, the angle of attack of the inside and outside wings is
not the same. the AOA of the inside (on the turn side) wing is
greater than the AOA of the outside wing and will stall before the
outside wing, and if the pilot allows this process to further develop
the glider will enter a spin.. We all know this, but I have to keep
reminding myself. The centered yaw string is not an indication of
equal AOA of the two wings. It only indicates the direction of air
flow right where the yaw string is. I think I better write this
on a postit and stick it to my panel!

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