Inadvertant PTT - Where do you put your hand?

On Apr 17, 4:29*pm, Nigel Pocock wrote:
As for your glass glider......How about moving the seat forward and
moving the rudder pedals forward, so you can reach the release?

Dosnt work for me. If i did that the stick would be jammed fully forward
by my crutch. As it is I have problems with some gliders getting full back
stick. Long body and short legs.

So what do you do?

On Apr 16, 5:59*pm, ContestID67 wrote:
On Apr 16, 5:40*pm, Steve Koerner wrote:

As the OP points out, there are two separate objectives. *One is to be
able to release quickly while the other is to not release
accidently.

Attaching the release cable to your hand has the potential to slightly
quicken the release action but in doing so, you are greatly
compromising the second goal. *Since we're offering 2 cent advise
her
GW

Thanks for your thoughts.

A PTT has the potential of...basically landing out. *That comes with
all the attendent issues of dinging/breaking the glider but rarely
harming the pilot. *I suppose this depends on a number of factors like
PTT height above the ground, the runway's over-run area, fences,
crops, etc, etc.

The other side of this coin is my fear (maybe unfounded) of the
dreaded "balloon". *In that case I am almost guaranteed to be
physically the worse for wear after the event...and maybe a lot
worse. *Because I witnessed one, I am hyper-sensitized to it.

This is all risk analysis. *What is the likelihood of the event I am
protecting against (balloon)? *Is it so remote that the concern is
unfounded and the "cure is worse than the disease"?

Thanks again for everyone's thoughts.

While I appreciate all the issues here I find myself with a different
view. I've been in the weeds twice with bad wing runners at high
desert airports and find that to be by far the higher risk.

My takeoff procedure is: 1) Flaps full negative to reduce the angle of
attack while the tailwheel is on the ground, 2) Hand on airbrake
handle at half open. Both 1&2 increase aileron effectiveness on my
ship. 3) Once I have aileron control, but well below flying speed,
close the divebrakes, move the flaps to tow position. 4) Ease the
stick forward to raise the tailwheel and move hand to near the
release, but not touching it. (I find the risk of accidental release
from turbulence to be greater than not being able to grab the
release). 5) Liftoff.

Procedure is slightly different for nosewheel/skid.

The point is that there is a distinct phase of flight where wing drop
and runway excursion is most likely and separate phase of flight where
ballooning is the main risk - they are in my experience always
separated by several seconds that allow me to do manage for both. I
suppose if you are doing a winch launch it might be different.

9B

On 4/17/2011 8:37 PM, Andy wrote:
While I appreciate all the issues here I find myself with a
different view. I've been in the weeds twice with bad wing runners
at high desert airports and find that to be by far the higher risk.

My takeoff procedure is: 1) Flaps full negative to reduce the angle
of attack while the tailwheel is on the ground, 2) Hand on airbrake
handle at half open. Both 1&2 increase aileron effectiveness on my
ship. 3) Once I have aileron control, but well below flying speed,
close the divebrakes, move the flaps to tow position. 4) Ease the
stick forward to raise the tailwheel and move hand to near the
release, but not touching it. (I find the risk of accidental release
from turbulence to be greater than not being able to grab the
release). 5) Liftoff.

Procedure is slightly different for nosewheel/skid.

The point is that there is a distinct phase of flight where wing
drop and runway excursion is most likely and separate phase of flight
where ballooning is the main risk - they are in my experience always
separated by several seconds that allow me to do manage for both. I
suppose if you are doing a winch launch it might be different.

9B

I used the same procedure on my ASW 20 C for many years. It worked well.
I further improved the situation by having a forward hook retrofitted.
That made the glider go significantly straighter at the beginning of the
launch than the CG hook that came with it originally.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

- "A Guide to Self-launching Sailplane Operation Mar/2004" Much of what
you need to know tinyurl.com/yfs7tnz

Eric has it right.
Different phases of flight and different launch methods = different
risks = different actions.

With a winch launch the prospect of a dropped wing is much smaller, and
the requirement to release immediately is imperative. Energy builds at a
significantly faster rate.

So the time on a winch launch that you would benefit from open airbrakes
is small.

With My Cirrus an aerotow would usually involve hand on airbrakes,
partially deployed until I have roll authority. Then close brakes and
move hand to lanyard for release. There are enough seconds between
aileron authority and flying speed that this is not a hurried scrabble.

On a winch launch the brakes are locked and the hand is on the release
lanyard right from the start. In the std Cirrus, even at 186cm I can't
reach the release while a winch is pushing me back into the seat, and
the time to aileron control is 2s - no time to drop a wing...

With the Kestrel there are flaps to complicate matters, I just leave
them in neutral for aerotow and +1 for winch. Still do the same airbrake
action - it significantly improves aileron control at low speed.

To see the effect for your self - try to balance on the main wheel in a
very light wind with the brakes closed, and open. No comparison...

I understand the reason this works is that the air flows around rather
than over the airbrake paddle - significantly increasing the free stream
velocity just outboard of the airbrake - which is where most gliders
have their ailerons starting.


--
Bruce Greeff
T59D #1771 & Std Cirrus #57

Eric has it right.
Different phases of flight and different launch methods = different
risks = different actions.

With a winch launch the prospect of a dropped wing is much smaller, and
the requirement to release immediately is imperative. Energy builds at a
significantly faster rate.

So the time on a winch launch that you would benefit from open airbrakes
is small.

With My Cirrus an aerotow would usually involve hand on airbrakes,
partially deployed until I have roll authority. Then close brakes and
move hand to lanyard for release. There are enough seconds between
aileron authority and flying speed that this is not a hurried scrabble.

On a winch launch the brakes are locked and the hand is on the release
lanyard right from the start. In the std Cirrus, even at 186cm I can't
reach the release while a winch is pushing me back into the seat, and
the time to aileron control is 2s - no time to drop a wing...

With the Kestrel there are flaps to complicate matters, I just leave
them in neutral for aerotow and +1 for winch. Still do the same airbrake
action - it significantly improves aileron control at low speed.

To see the effect for your self - try to balance on the main wheel in a
very light wind with the brakes closed, and open. No comparison...

I understand the reason this works is that the air flows around rather
than over the airbrake paddle - significantly increasing the free stream
velocity just outboard of the airbrake - which is where most gliders
have their ailerons starting.


--
Bruce Greeff
T59D #1771 & Std Cirrus #57

On Apr 18, 1:22*pm, BruceGreeff wrote:
Eric has it right.
Different phases of flight and different launch methods = different
risks = different actions.

With a winch launch the prospect of a dropped wing is much smaller, and
the requirement to release immediately is imperative. Energy builds at a
significantly faster rate.

So the time on a winch launch that you would benefit from open airbrakes
is small.

With My Cirrus an aerotow would usually involve hand on airbrakes,
partially deployed until I have roll authority. Then close brakes and
move hand to lanyard for release. There are enough seconds between
aileron authority and flying speed that this is not a hurried scrabble.

On a winch launch the brakes are locked and the hand is on the release
lanyard right from the start. In the std Cirrus, even at 186cm I can't
reach the release while a winch is pushing me back into the seat, and
the time to aileron control is 2s - no time to drop a wing...

With the Kestrel there are flaps to complicate matters, I just leave
them in neutral for aerotow and +1 for winch. Still do the same airbrake
action - it significantly improves aileron control at low speed.

To see the effect for your self - try to balance on the main wheel in a
very light wind with the brakes closed, and open. No comparison...

I understand the reason this works is that the air flows around rather
than over the airbrake paddle - significantly increasing the free stream
velocity just outboard of the airbrake - which is where most gliders
have their ailerons starting.

--
Bruce Greeff
T59D #1771 & Std Cirrus #57

One thing to add about wing drop.

On most gliders with a tailwheel or skid the "tail on the ground" AOA
is relatively high - otherwise you can't lift off. In addition, a
downward deflected aileron further increases the AOA. At the beginning
of the roll I have regularly experienced the beginning of a wing drop
and found that corrective aileron to pick the wing up actually makes
it drop faster because you stall the dropping wing at the tip.

Recommended technique: If you don't get a response to your control
input to correct wing drop it often means that the airspeed is still
too low and you will likely get a better response by neutralizing the
ailerons for a second or so for the flow at the tip to re-establish,
then applying just a little corrective aileron to pick the wing up
without stalling. It takes some practice and a lot of discipline.

Works on rollout too.

9B

At 04:21 19 April 2011, Andy wrote:

On most gliders with a tailwheel or skid the "tail on the ground" AOA
is relatively high - otherwise you can't lift off. In addition, a
downward deflected aileron further increases the AOA. At the beginning
of the roll I have regularly experienced the beginning of a wing drop
and found that corrective aileron to pick the wing up actually makes
it drop faster because you stall the dropping wing at the tip.

Recommended technique: If you don't get a response to your control
input to correct wing drop it often means that the airspeed is still
too low and you will likely get a better response by neutralizing the
ailerons for a second or so for the flow at the tip to re-establish,
then applying just a little corrective aileron to pick the wing up
without stalling. It takes some practice and a lot of discipline.

Works on rollout too.

9B


Andy, wouldn't that have the oppisite effect on the other aileron as well
by decreasing the AOA and making it more effective thereby canceling out
making all things equal? I would venture that kicking in highwing rudder
would help more by speeding up the low wing and slowing down the high wing
with double the effectiveness. Just a thought


CH Ventus B

"If we are all "just dust in the wind", then I want to be at the top of a Huge Dust Devil!"

On Apr 19, 2:44*pm, Cliff Hilty
wrote:
At 04:21 19 April 2011, Andy wrote:





On most gliders with a tailwheel or skid the "tail on the ground" AOA
is relatively high - otherwise you can't lift off. In addition, a
downward deflected aileron further increases the AOA. At the beginning
of the roll I have regularly experienced the beginning of a wing drop
and found that corrective aileron to pick the wing up actually makes
it drop faster because you stall the dropping wing at the tip.

Recommended technique: If you don't get a response to your control
input to correct wing drop it often means that the airspeed is still
too low and you will likely get a better response by neutralizing the
ailerons for a second or so for the flow at the tip to re-establish,
then applying just a little corrective aileron to pick the wing up
without stalling. *It takes some practice and a lot of discipline.

Works on rollout too.

9B

Andy, wouldn't that have the oppisite effect on the other aileron as well
by decreasing the AOA and making it more effective thereby canceling out
making all things equal? I would venture that kicking in highwing rudder
would help more by speeding up the low wing and slowing down the high wing
with double the effectiveness. Just a thought

CH Ventus B

"If we are all "just dust in the wind", then I want to be at the top of a Huge Dust Devil!"- Hide quoted text -

- Show quoted text -

I've read about using the rudder many times. I have experience in
very few gliders In my Speed Astir, I get some aileron authority (I
start with full neg flaps) long before the rudder will change my line
even a little. I get aileron first, elevator next, then rudder last.
My lack of rudder response may well be due to using a roller blade
wheel instead of the hard nylon furniture caster that came with it, or
the skid that was probably original equipment.

On Apr 19, 3:11*pm, Grider Pirate wrote:
On Apr 19, 2:44*pm, Cliff Hilty





wrote:
At 04:21 19 April 2011, Andy wrote:

On most gliders with a tailwheel or skid the "tail on the ground" AOA
is relatively high - otherwise you can't lift off. In addition, a
downward deflected aileron further increases the AOA. At the beginning
of the roll I have regularly experienced the beginning of a wing drop
and found that corrective aileron to pick the wing up actually makes
it drop faster because you stall the dropping wing at the tip.

Recommended technique: If you don't get a response to your control
input to correct wing drop it often means that the airspeed is still
too low and you will likely get a better response by neutralizing the
ailerons for a second or so for the flow at the tip to re-establish,
then applying just a little corrective aileron to pick the wing up
without stalling. *It takes some practice and a lot of discipline.

Works on rollout too.

9B

Andy, wouldn't that have the oppisite effect on the other aileron as well
by decreasing the AOA and making it more effective thereby canceling out
making all things equal? I would venture that kicking in highwing rudder
would help more by speeding up the low wing and slowing down the high wing
with double the effectiveness. Just a thought

CH Ventus B

"If we are all "just dust in the wind", then I want to be at the top of a Huge Dust Devil!"- Hide quoted text -

- Show quoted text -

I've read about using the rudder many times. *I have experience in
very few gliders In my Speed Astir, I get some aileron authority (I
start with full neg flaps) long before the rudder will change my line
even a little. I get aileron first, elevator next, then rudder last.
My lack of rudder response may well be due to using a roller blade
wheel instead of the hard nylon furniture caster that came with it, or
the skid that was probably original equipment.- Hide quoted text -

- Show quoted text -

D'oh! As to the original question: For auto-tows (no winch experience)
I hold the release until I have solid aileron, then move to the flap
handle. For Aero tows, I keep my hand ON it on tow. I don't much
worry about an inadvertent release. There's not much subtle about a
Speed Astir, and the release is no exception. It takes a very firm
pull.

On Apr 19, 2:44*pm, Cliff Hilty
wrote:
At 04:21 19 April 2011, Andy wrote:





On most gliders with a tailwheel or skid the "tail on the ground" AOA
is relatively high - otherwise you can't lift off. In addition, a
downward deflected aileron further increases the AOA. At the beginning
of the roll I have regularly experienced the beginning of a wing drop
and found that corrective aileron to pick the wing up actually makes
it drop faster because you stall the dropping wing at the tip.

Recommended technique: If you don't get a response to your control
input to correct wing drop it often means that the airspeed is still
too low and you will likely get a better response by neutralizing the
ailerons for a second or so for the flow at the tip to re-establish,
then applying just a little corrective aileron to pick the wing up
without stalling. *It takes some practice and a lot of discipline.

Works on rollout too.

9B

Andy, wouldn't that have the oppisite effect on the other aileron as well
by decreasing the AOA and making it more effective thereby canceling out
making all things equal? I would venture that kicking in highwing rudder
would help more by speeding up the low wing and slowing down the high wing
with double the effectiveness. Just a thought

CH Ventus B

"If we are all "just dust in the wind", then I want to be at the top of a Huge Dust Devil!"

If I understand correctly Cliff you are asking if negative aileron on
the up wing would create enough negative lift to offset the tip stall
on the down wing. I think even with full negative aileron the
unstalled wing tip is producing positive lift (it's reduced, but not
negative) while the stalled wing tip is producing very little lift. To
convince yourself of this think about trying to recover from a spin
entry with opposite aileron only. It doesn't help much at all - you
are still going into the spin unless and until you get the inside wing
flying again.

I generally have aileron authority at a lower speed than I have rudder
authority - at least with a tailwheel like my -27 has. Andy once the
wingtip is on the ground forget it. Other gliders could be different.
Kicking the rudder is generally a decent way to pick up a wing if you
get an upset at above rudder minimum control speed.

It seems to work for me.

9B