Does anyone use a tug tow hook that releases automatically whenglider kites?

On 22/02/2014 20:21, Chris Rollings wrote:
The time difference to go from low tow to kiting compared to high tow to
kiting is about 1 second - try it at safe altitude.

I read your posts carefully, Chris and I don't recall any low tow
experiments. The closest was your description of the glider with the
PA-18 as "in a slightly low normal tow position" which I take to be high
tow for you. So I don't think you speak with any special authority on
low tow. Correct me if I'm wrong. I have a lot of experience with low
tow and your 1 second is wrong unless a normally competent pilot intends
- suicidally - to deliberately go kiting. To use your own words: it's
"...something unlikely to occur accidentally, even with an inexperienced
glider pilot."

...As observed you can't
take-off in low tow so the highest risk time, just after take off when the
combination is accelerating, is exactly the same.

....and no worse. And needs the same training whether it ends in high or
low tow.

The transition from
normal tow to low tow, early in the climb, puts the glider into the
turbulence of the prop-wash which may well cause the, less than one second,
loss of control which is all that is needed to start the kiting.

You originally said 2 to 3 seconds from high tow so it's got to be at
least 4 seconds from low tow on your own figures above - but we won't
quibble about trivia. All I can say is that it's not our - very
considerable - experience. You're welcome to learn nothing from anybody
else (a very English habit, that) but in that case let's drop the
pretence that kiting is a seriously difficult problem to solve and
worthy of vast quantities of speculative rubbish.

Finally,
low tow on a glider with a C of G hook, leaves the rope wrapped around the
side of the cockpit, not really a good idea and C of G hooks are where the
danger lies.
The cheapest mechanical solution is, fit a nose hook to any glider that is
going to be aerotowed.

That's why aerotow is only permitted on nose hooks in Oz. It's the
obvious counterpart of low tow. You don't travel much, do you? I have
done low tows on a CG hook (at Hus Bos) and they were a non-event.

My best estimate of low level kiting fatal/serious accident frequency is of
the order of one in a million. "Tens of thousands of aerotows" is not a
big enough sample to draw conclusions.

Mmm. Statistics aren't your strong point, are they Chris?

I must say I'm quite stunned by your negativity re low tow, especially
if you were once CFI at Booker. I read and was impressed by your tests.
You seemed to take the problem really seriously. This is the reality:
there is a simple solution (not perfect) available immediately to
minimise the risk of kiting. If it's a serious problem, it should be
implemented while the fancy gimcrackery is developed and I'm surprised
you're fighting it. Otherwise, it's not a problem you actually take all
that seriously. As you said, one in a million. Australia thinks it's
serious enough to have actually done something. It appears you don't.
That's fair enough, it's your call, so let's forget all the bull**** and
talk about something else.

GC


At 07:58 22 February 2014, GC wrote:
On 22/02/2014 16:17, Alan wrote:

...You don't get kiting if you fly normal "high" tow behind the
towplane,
if you remain in control.

If you don't remain in control, starting from low tow is not going
to
make a lot of difference.

Experience (tens of thousands of aerotows) shows there is an enormous
difference. The inadequate control and time to go from high tow to
kiting is orders of magnitude different from that required to go from
low tow to kiting. In fact, I've never heard of that ever happening.
Even with low time students. Kiting from high tow, however, is
apparently so common as to need a whole new system of electronic
whizzbangery and gallons of bandwidth to stop.

If the tug has just lifted off, being in low tow sounds a bit
difficult,
but that would be a particularly hazardous time.

Yes. Liftoff is a time to be wary and we train accordingly.
Nevertheless, all I can say is that low tow has prevented kiting
accidents for many years. But don't take my word for it, keep this
ridiculous discussion going with another screwball idea for pivoting,
autoswivelling, pitch-sensing, stick-following nonsense.

If the issue is serious - as it was in Australia - flying low tow will
solve it. If it isn't - see my previous post.

GC



As for automatic methods to mitigate the problem, perhaps the
solution
is not to modify tow planes, but to modify gliders. If the glider is
in a very high pitch attitude on tow, it might be a good time to
automatically
release.

Another modification might be to attach the tow rope to the top of
the
glider.
This would cause the tow force to pitch the glider down.


Is this more of a problem when folks try to tow a slow glider like a
2-33 at
high speeds?

Alan

On Sunday, February 9, 2014 5:27:23 PM UTC-5, son_of_flubber wrote:
This topic was buried in a drifting degenerate thread. I'm wondering if anyone knows more about the tow hook innovation mentioned below by UH.



On Saturday, February 8, 2014 9:31:13 AM UTC-5, son_of_flubber wrote:



Why does the pilot need to pull the release if the glider kites? Why is the release for a deadly tow position not fully automatic? Is a simple purely mechanical, totally foolproof and 100% automatic release not possible? As the guy in the glider, I would be fine with a 100% automatic release. If I kite, release me immediately.





On Sunday, February 9, 2014 5:05:52 PM UTC-5, wrote:



There was a design and prototype of a release like this created many years ago and published, I believe, in Soaring magazine. I know if no one that has adopted this which makes it fairly clear that this is not perceived as a huge problem.



Although FAA approval might be an obstacle, a system that would work would be to connect the elevator cable to the tow release cable such that the last small increment of travel toward full up elevator of the tow ship would pull the release.

An additional concern that tow pilots should be aware of is the possibility of an accelerated stall right at release of a kiting glider. With full back stick the angle of attack might increase so rapidly the tug pilot wouldn't get the stick forward fast enough.

On Saturday, February 22, 2014 4:21:55 AM UTC-5, Chris Rollings wrote:

The cheapest mechanical solution is, fit a nose hook to any glider that is
going to be aerotowed.

Does the record support this? Are all the fatal kiting incidents connected to a CG hook on the glider? Has there ever been a fatal kiting incident connected to a glider nose hook?

Aren't new gliders required to have a nose hook for aerotow?

On Saturday, February 22, 2014 8:04:43 AM UTC-5, Karl Striedieck wrote:
On Sunday, February 9, 2014 5:27:23 PM UTC-5, son_of_flubber wrote: This topic was buried in a drifting degenerate thread. I'm wondering if anyone knows more about the tow hook innovation mentioned below by UH. On Saturday, February 8, 2014 9:31:13 AM UTC-5, son_of_flubber wrote: Why does the pilot need to pull the release if the glider kites? Why is the release for a deadly tow position not fully automatic? Is a simple purely mechanical, totally foolproof and 100% automatic release not possible? As the guy in the glider, I would be fine with a 100% automatic release. If I kite, release me immediately. On Sunday, February 9, 2014 5:05:52 PM UTC-5, wrote: There was a design and prototype of a release like this created many years ago and published, I believe, in Soaring magazine. I know if no one that has adopted this which makes it fairly clear that this is not perceived as a huge problem.. Although FAA approval might be an obstacle, a system that would work would be to connect the elevator cable to the tow release cable such that the last small increment of travel toward full up elevator of the tow ship would pull the release. An additional concern that tow pilots should be aware of is the possibility of an accelerated stall right at release of a kiting glider. With full back stick the angle of attack might increase so rapidly the tug pilot wouldn't get the stick forward fast enough.

Full back stick is where I am during run up, beginning of take off roll, and commonly in the flare.
A combination of inputs might be made to work if including:
Climb power above some threshold
Plus some predetermind degree of up pitch control input
Plus some predetermined air speed.
Maybe find a way to add in a rate of deceleration input.
Maybe add reduction in G force for some predetermined time
If the combinations fall into the specified range, you have as problem.
Need is to avoid a single input that may be false.
FWIW
UH

On Saturday, February 22, 2014 8:41:07 AM UTC-5, son_of_flubber wrote:
On Saturday, February 22, 2014 4:21:55 AM UTC-5, Chris Rollings wrote: The cheapest mechanical solution is, fit a nose hook to any glider that is going to be aerotowed. Does the record support this? Are all the fatal kiting incidents connected to a CG hook on the glider? Has there ever been a fatal kiting incident connected to a glider nose hook? Aren't new gliders required to have a nose hook for aerotow?

Gliders with nose hooks don't kite. They may be flown out of position but kiting effect due to low and aft hook is eliminated.
Certification now requires nose hooks for aero tow, in part due to findings of studies described before.
UH

On Saturday, February 22, 2014 1:58:28 AM UTC-6, GC wrote:
On 22/02/2014 16:17, Alan wrote:



...You don't get kiting if you fly normal "high" tow behind the towplane,

if you remain in control.



If you don't remain in control, starting from low tow is not going to

make a lot of difference.



Experience (tens of thousands of aerotows) shows there is an enormous

difference. The inadequate control and time to go from high tow to

kiting is orders of magnitude different from that required to go from

low tow to kiting. In fact, I've never heard of that ever happening.

Even with low time students. Kiting from high tow, however, is

apparently so common as to need a whole new system of electronic

whizzbangery and gallons of bandwidth to stop.



If the tug has just lifted off, being in low tow sounds a bit difficult,

but that would be a particularly hazardous time.



Yes. Liftoff is a time to be wary and we train accordingly.

Nevertheless, all I can say is that low tow has prevented kiting

accidents for many years. But don't take my word for it, keep this

ridiculous discussion going with another screwball idea for pivoting,

autoswivelling, pitch-sensing, stick-following nonsense.



If the issue is serious - as it was in Australia - flying low tow will

solve it. If it isn't - see my previous post.



GC







As for automatic methods to mitigate the problem, perhaps the solution

is not to modify tow planes, but to modify gliders. If the glider is

in a very high pitch attitude on tow, it might be a good time to automatically

release.



Another modification might be to attach the tow rope to the top of the glider.

This would cause the tow force to pitch the glider down.





Is this more of a problem when folks try to tow a slow glider like a 2-33 at

high speeds?



Alan


GC is making his point for low tows very convincingly - why is he immediately being ripped, Chris? Preparing and steering into low tow at a safe altitude, say 300', means to mentally and then practically pushing the stick forward and then holding in the low tow position. That's the opposite maneuver of what's leading to kiting. Drifting upwards takes you into the prop wash and again, it takes forward stick pressure to move into the safe spot. That feedback mechanism is correctly maintaining the intended safe spot while in the normal tow position only visual cues are being used.
I think I'll give the low tow a try, if ever that polar vortex over Chicago makes like tree...
Herb

At 12:33 22 February 2014, GC wrote:
On 22/02/2014 20:21, Chris Rollings wrote:
The time difference to go from low tow to kiting compared to high tow
to
kiting is about 1 second - try it at safe altitude.

I read your posts carefully, Chris and I don't recall any low tow
experiments. The closest was your description of the glider with the
PA-18 as "in a slightly low normal tow position" which I take to be high
tow for you. So I don't think you speak with any special authority on
low tow. Correct me if I'm wrong. I have a lot of experience with low
tow and your 1 second is wrong unless a normally competent pilot intends
- suicidally - to deliberately go kiting. To use your own words: it's
"...something unlikely to occur accidentally, even with an inexperienced
glider pilot."

...As observed you can't
take-off in low tow so the highest risk time, just after take off when
the
combination is accelerating, is exactly the same.

....and no worse. And needs the same training whether it ends in high or

low tow.

The transition from
normal tow to low tow, early in the climb, puts the glider into the
turbulence of the prop-wash which may well cause the, less than one
second,
loss of control which is all that is needed to start the kiting.

You originally said 2 to 3 seconds from high tow so it's got to be at
least 4 seconds from low tow on your own figures above - but we won't
quibble about trivia. All I can say is that it's not our - very
considerable - experience. You're welcome to learn nothing from anybody
else (a very English habit, that) but in that case let's drop the
pretence that kiting is a seriously difficult problem to solve and
worthy of vast quantities of speculative rubbish.

It takes 2 - 3 seconds from high tow and as you say probably 4 seconds from
low tow, but after the first 1 second it's inevitable unless the release is
pulled then and that is equally true of low and high tow. May I suggest
that you take a light weight glider up on a C of G hook and, at a safe
height, in low tow, pitch the glider up about 25 degrees and observe what
happens, then report back on here.

The point that is overlooked is that, faced with a totally unexpected and
very alarming picture, pilots do not react in one second or even two and
when they do react the physical act or reaching for the release and pulling
it takes at least a couple more seconds, probably more - too late, it's all
over. Taking off with a hand on the release might just help, though I
doubt it would help enough and I'm pretty sure it would cause significantly
more accidents with unintentional releases.


Finally,
low tow on a glider with a C of G hook, leaves the rope wrapped around
the
side of the cockpit, not really a good idea and C of G hooks are where
the
danger lies.
The cheapest mechanical solution is, fit a nose hook to any glider that
is
going to be aerotowed.

That's why aerotow is only permitted on nose hooks in Oz. It's the
obvious counterpart of low tow. You don't travel much, do you? I have
done low tows on a CG hook (at Hus Bos) and they were a non-event.

My best estimate of low level kiting fatal/serious accident frequency
is
of
the order of one in a million. "Tens of thousands of aerotows" is not
a
big enough sample to draw conclusions.

Mmm. Statistics aren't your strong point, are they Chris?

Why do you say that?


I must say I'm quite stunned by your negativity re low tow, especially
if you were once CFI at Booker. I read and was impressed by your tests.
You seemed to take the problem really seriously. This is the reality:
there is a simple solution (not perfect) available immediately to
minimise the risk of kiting. If it's a serious problem, it should be
implemented while the fancy gimcrackery is developed and I'm surprised
you're fighting it. Otherwise, it's not a problem you actually take all
that seriously. As you said, one in a million. Australia thinks it's
serious enough to have actually done something. It appears you don't.
That's fair enough, it's your call, so let's forget all the bull**** and
talk about something else.

I have always taught low tow as useful for avoiding a slack line when
towing cross-country, I'm not against it. I simply don't believe that it
significantly, if at all reduces the risk of a kiting incident. I would be
pleased to see a description of some flight tests that proved me wrong.


GC


At 07:58 22 February 2014, GC wrote:
On 22/02/2014 16:17, Alan wrote:

...You don't get kiting if you fly normal "high" tow behind the
towplane,
if you remain in control.

If you don't remain in control, starting from low tow is not
going
to
make a lot of difference.

Experience (tens of thousands of aerotows) shows there is an enormous
difference. The inadequate control and time to go from high tow to
kiting is orders of magnitude different from that required to go from
low tow to kiting. In fact, I've never heard of that ever happening.
Even with low time students. Kiting from high tow, however, is
apparently so common as to need a whole new system of electronic
whizzbangery and gallons of bandwidth to stop.

If the tug has just lifted off, being in low tow sounds a bit
difficult,
but that would be a particularly hazardous time.

Yes. Liftoff is a time to be wary and we train accordingly.
Nevertheless, all I can say is that low tow has prevented kiting
accidents for many years. But don't take my word for it, keep this
ridiculous discussion going with another screwball idea for pivoting,
autoswivelling, pitch-sensing, stick-following nonsense.

If the issue is serious - as it was in Australia - flying low tow will
solve it. If it isn't - see my previous post.

GC



As for automatic methods to mitigate the problem, perhaps the
solution
is not to modify tow planes, but to modify gliders. If the glider is
in a very high pitch attitude on tow, it might be a good time to
automatically
release.

Another modification might be to attach the tow rope to the top
of
the
glider.
This would cause the tow force to pitch the glider down.


Is this more of a problem when folks try to tow a slow glider
like
a
2-33 at
high speeds?

Alan

I think the Aussies figured this out.

Nose hook on glider plus low tow (and suitable training for the high-low transition, which really isn't that hard) solves the problem.

Now, is the key part of the solution the glider hook position, or the tow position?

Without any statistics, my scientific wild-ass guess (SWAG) is about 80% nose tow hook on glider and 19% low tow; I'll concede 1% to training just because I know how poorly most glider pilots listen to any training when "safety" is involved...

Seriously, I think the key is to stop towing on CG hooks in turbulent conditions. Or at least tell the tow pilot when a CG hook is being used and make sure the glider pilot is fully aware of the potential for kiting. Perhaps insist that CG gliders go to low tow.

And if anyone thinks you can release a towplane Schweizer release under tension, especially with an upward component, I suggest that you try it on the ground. You may be unpleasantly surprised.

OT, been watching "Rake" (the original Aussie version) on DTV. Excellent!

Now, where is that Bearcat flight manual I've been reading?

Fun thread, hope is makes people think a bit about what CAN happen on tow, and saves a life or two.

Kirk
66

At 14:28 22 February 2014, wrote:
On Saturday, February 22, 2014 1:58:28 AM UTC-6, GC wrote:
On 22/02/2014 16:17, Alan wrote:
=20
=20
=20
...You don't get kiting if you fly normal "high" tow behind the
towplan=
e,
=20
if you remain in control.
=20

=20
If you don't remain in control, starting from low tow is not going
t=
o
=20
make a lot of difference.
=20
=20
=20
Experience (tens of thousands of aerotows) shows there is an
enormous=20
=20
difference. The inadequate control and time to go from high tow to=20
=20
kiting is orders of magnitude different from that required to go
from=20
=20
low tow to kiting. In fact, I've never heard of that ever
happening.=20
=20
Even with low time students. Kiting from high tow, however, is=20
=20
apparently so common as to need a whole new system of electronic=20
=20
whizzbangery and gallons of bandwidth to stop.
=20
=20
=20
If the tug has just lifted off, being in low tow sounds a bit
diffic=
ult,
=20
but that would be a particularly hazardous time.
=20
=20
=20
Yes. Liftoff is a time to be wary and we train accordingly.=20
=20
Nevertheless, all I can say is that low tow has prevented kiting=20
=20
accidents for many years. But don't take my word for it, keep this=20
=20
ridiculous discussion going with another screwball idea for
pivoting,=20
=20
autoswivelling, pitch-sensing, stick-following nonsense.
=20
=20
=20
If the issue is serious - as it was in Australia - flying low tow
will=20
=20
solve it. If it isn't - see my previous post.
=20
=20
=20
GC
=20
=20
=20

=20

=20
As for automatic methods to mitigate the problem, perhaps the
soluti=
on
=20
is not to modify tow planes, but to modify gliders. If the glider is
=20
in a very high pitch attitude on tow, it might be a good time to
automa=
tically
=20
release.
=20

=20
Another modification might be to attach the tow rope to the top of
t=
he glider.
=20
This would cause the tow force to pitch the glider down.
=20

=20

=20
Is this more of a problem when folks try to tow a slow glider like
a=
2-33 at
=20
high speeds?
=20

=20
Alan
=20

GC is making his point for low tows very convincingly - why is he
immediate=
ly being ripped, Chris? Preparing and steering into low tow at a safe
alti=
tude, say 300',

If you wait 'till 300 feet the majority of the risk of a fatal kiting
incident is already behind you, once past 400 feet there is just about
enough height for the tow pilot to recover.

means to mentally and then practically pushing the stick
fo=
rward and then holding in the low tow position. That's the opposite
maneuv=
er of what's leading to kiting. Drifting upwards takes you into the prop
w=
ash and again, it takes forward stick pressure to move into the safe
spot.
=
That feedback mechanism is correctly maintaining the intended safe spot
wh=
ile in the normal tow position only visual cues are being used.
I think I'll give the low tow a try, if ever that polar vortex over
Chicago=
makes like tree...
Herb


I've been aware of the Australian preference for low tow and the reasons
for it for over 30 years. My own flight testing and experience lead me to
believe that it does not significantly reduce the probability of a kiting
accident.

On 23/02/2014 01:31, Chris Rollings wrote:

It takes 2 - 3 seconds from high tow and as you say probably 4 seconds from
low tow, but after the first 1 second it's inevitable unless the release is
pulled then and that is equally true of low and high tow. May I suggest
that you take a light weight glider up on a C of G hook and, at a safe
height, in low tow, pitch the glider up about 25 degrees and observe what
happens, then report back on here.

Chris, that is complete nonsense. How many low tows have you flown?
From normal low tow, kiting is NEVER inevitable after 1 second. It's
ridiculous to claim it's inevitable from low tow in exactly the same
time as high tow. Do you tow on 10 foot ropes?? Besides, low tow means
the glider has to transit the wake before kiting reaches the point of no
return. Even really bad pilots notice that and react - before kiting is
inevitable. I have NEVER seen even a student pitch 25 degrees nose up
from low tow, nor have I ever heard of such a thing happening uncommanded.

The point that is overlooked is that, faced with a totally unexpected and
very alarming picture, pilots do not react in one second or even two and
when they do react the physical act or reaching for the release and pulling
it takes at least a couple more seconds, probably more - too late, it's all
over. Taking off with a hand on the release might just help, though I
doubt it would help enough and I'm pretty sure it would cause significantly
more accidents with unintentional releases.

This is getting silly. What point are you trying to make? Clearly you
have a lot of instructing behind you but the level of stupidity and
incompetence you appear to expect from ordinary pilots is way below my
experience. Is low tow so uncool that you have to attack it to the
point of complete unreasonableness?

All I can repeat is that many years of experience in Australia has shown
that low tow prevents kiting. You can attack me theoretically as long
as you like but I will continue to say that our experience is different.
And I think you'd agree that experience trumps theory.

GC



Finally,
low tow on a glider with a C of G hook, leaves the rope wrapped around
the
side of the cockpit, not really a good idea and C of G hooks are where
the
danger lies.
The cheapest mechanical solution is, fit a nose hook to any glider that
is
going to be aerotowed.

That's why aerotow is only permitted on nose hooks in Oz. It's the
obvious counterpart of low tow. You don't travel much, do you? I have
done low tows on a CG hook (at Hus Bos) and they were a non-event.

My best estimate of low level kiting fatal/serious accident frequency
is
of
the order of one in a million. "Tens of thousands of aerotows" is not
a
big enough sample to draw conclusions.

Mmm. Statistics aren't your strong point, are they Chris?

Why do you say that?


I must say I'm quite stunned by your negativity re low tow, especially
if you were once CFI at Booker. I read and was impressed by your tests.
You seemed to take the problem really seriously. This is the reality:
there is a simple solution (not perfect) available immediately to
minimise the risk of kiting. If it's a serious problem, it should be
implemented while the fancy gimcrackery is developed and I'm surprised
you're fighting it. Otherwise, it's not a problem you actually take all
that seriously. As you said, one in a million. Australia thinks it's
serious enough to have actually done something. It appears you don't.
That's fair enough, it's your call, so let's forget all the bull**** and
talk about something else.

I have always taught low tow as useful for avoiding a slack line when
towing cross-country, I'm not against it. I simply don't believe that it
significantly, if at all reduces the risk of a kiting incident. I would be
pleased to see a description of some flight tests that proved me wrong.


GC


At 07:58 22 February 2014, GC wrote:
On 22/02/2014 16:17, Alan wrote:

...You don't get kiting if you fly normal "high" tow behind the
towplane,
if you remain in control.

If you don't remain in control, starting from low tow is not
going
to
make a lot of difference.

Experience (tens of thousands of aerotows) shows there is an enormous
difference. The inadequate control and time to go from high tow to
kiting is orders of magnitude different from that required to go from
low tow to kiting. In fact, I've never heard of that ever happening.
Even with low time students. Kiting from high tow, however, is
apparently so common as to need a whole new system of electronic
whizzbangery and gallons of bandwidth to stop.

If the tug has just lifted off, being in low tow sounds a bit
difficult,
but that would be a particularly hazardous time.

Yes. Liftoff is a time to be wary and we train accordingly.
Nevertheless, all I can say is that low tow has prevented kiting
accidents for many years. But don't take my word for it, keep this
ridiculous discussion going with another screwball idea for pivoting,
autoswivelling, pitch-sensing, stick-following nonsense.

If the issue is serious - as it was in Australia - flying low tow will
solve it. If it isn't - see my previous post.

GC



As for automatic methods to mitigate the problem, perhaps the
solution
is not to modify tow planes, but to modify gliders. If the glider is
in a very high pitch attitude on tow, it might be a good time to
automatically
release.

Another modification might be to attach the tow rope to the top
of
the
glider.
This would cause the tow force to pitch the glider down.


Is this more of a problem when folks try to tow a slow glider
like
a
2-33 at
high speeds?

Alan