Leading Turns with Rudder - Revisited

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.

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

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

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 |

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

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

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

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

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

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