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

GC, the GFA put out a safety poster around 30 years ago that actually had
line drawings, of the photos taken of the test I described, all
superimposed on one another (if you can find a copy and make it accessible,
that would help the discussion). I believe the banning of C of G hooks for
aerotowing and the adoption of low tow at about that time were also, at
least in part, the result of those tests.

I think the banning of C of G hooks is the primary reason for Australia's
good record on these sort of accidents, the use of low tow, whilst it may
have other benefits does not, in my opinion, contribute significantly, if
at all.

When the weather improves in the UK and I can get some spare time, I plan
to conduct some more tests, with another aircraft alongside to video them.
I'll include a kiting departure on a C of G hook from low tow as one of the
tests.

It is possible to get tow plane upsets resulting from significant glider
out of position events when on a nose hook. However they don't happen as
fast and there is often time for one or other pilot to release and they
don't become irrecoverable in the way that a kiting event is.

At 04:17 24 February 2014, GC wrote:
On 24/02/2014 02:00, Steve Leonard wrote:
I hear you on the low tow, GC. It is another of those perceptions of
"It isn't what we do, so it must be dangerous." Agree that it will
change the dynamics involved, as well. Did Australia go to low tow
to prevent kiting, or was it for some other reason and that was a
side benefit? I know that high tow increases the trim drag on the
towplane, and low tow reduces it, so on low powered towplanes, this
can be the difference between climbing and not. With America tending
to be a land of excess (horsepower in our towplanes), it is seldom an
issue.

So, I am curious. Was the change made to improve climb rates and you
just have not seen kiting events in Australia, or was there a
significant kiting problem, and low tow was determined to be a
solution? No, I am not being snide or snarky, I do not know and
would like ot learn.

The change was made well before my time in soaring (at least 30 years
ago - in the era where K-6's were just disappearing) but I understand
that kiting specifically and easier control on tow generally were the
reasons for the change. Certainly, it was nothing to do with climb
rates.

Like the Western US and South Africa, Australia experiences strong,
sharp-edged thermals which can be challenging to handle on tow. As
Chris's experiments showed, low wing loading gliders are more
susceptible to kiting and it was a real problem at the time. Low tow
isn't a silver bullet (nothing in aviation is) but it certainly stops
these problems becoming accidents in a way that apparently still happens
in the UK and US.

I believe that mandatory nose hooks for aerotow came in at the same time
but I can't confirm that. As Kirk said, nose hook aerotow is probably
the more important change but my instructing experience makes me think
that both play an important part.

I'm sure that what Australia did may well be overkill for the Eastern US
and much of Europe but I entered the discussion simply to point out that
no electronic solution was needed. A perfectly simple operational
change would secure all the safety anyone wanted - if that was the point
of the discussion. Otherwise it looked like a solution in search of a
problem.

I have nothing useful to contribute on low/high-powered tugs. I've
never noticed any difference. I will say that I've never complained of
excess power in any aircraft I've flown!

GC

Eyes and ears open, willing to learn.

Steve Leonard

At 04:40 24 February 2014, GC wrote:
On 24/02/2014 04:23, Dave Nadler wrote:
I'm confused by a couple of statements in this thread...

1) "Low tow prevents kiting"
Doesn't the kiting event often happen in early take-off,
just as glider is leaving the ground, and before low-tow
is established???

Yes, it does, but only on a C of G hook.


I don't know. We haven't had enough recent kiting accidents in Oz to
know.


2) "Nose hook prevents kiting"
Didn't we have at least one fatal accident in USA
with a nosehook (L-13 IIRCC)??? Others???
Anybody have any facts (Yes, I know, its RAS, but...)???
I'm not saying nose-hooks don't help, however...

So what ARE you saying? Swallows, summer? Just stirring the pot?

Dave, I'm well aware of the much yada yada on r.a.s. regarding low/high
tow of which you've been part. I'm not going to be drawn into it. As I
said, a lot of it appears to me to be based on personality in the form
of "real men fly high tow - and they do it on CG hooks!"

I only wanted to say that if kiting is a problem, nose hooks and low tow
will reduce it to insignificance. If those practices are not worth
adopting, kiting's not a real problem.

GC

But then, I'm easily confused...
....just keep taking the tablets like I told you...
Thanks,
Best Regards, Dave

Can we just not agree that the use of low tow and the non use of CoG hooks
for aerotowing reduce the likelihood of a kiting event occurring?

The available evidence may show that neither will completely prevent the
occurrence but there is evidence to show that there is an apparent
reduction in occurrence. Complete eradication might be the ideal but
reduction is a start in the right direction.

There is a lot to be said for studying "Best Practice" but you have to act
on it. If you are used to high tow I would be the first to admit that low
tow looks weird but it is much more stable and requires much less work to
keep the proper position. It appears to me that people are saying that out
of position in low tow is a much less serious situation that out of
position in high tow (too low is better than too high)

Not very relevant to the discussion, but on one occasion a long time ago, I
was on the long rope (low tow) of a dual tow going up to do a formation
aerobatic display at an airshow. The glider I was in was a Pilatus B4
which only had a C of G hook (this was 1974 some years before the tests
described earlier).

Approaching the release point, the tow-plane ran into strong lift under a
small Cb that had drifted in over the airfield. He throttled back and
lowered the nose to avoid being sucked up into the cloud (and Heathrow's
airspace). Both gliders started to catch up with the tow plane and
developed slack lines. I didn't release because I didn't want to have my
rope wrap around the other glider on the short rope and he hadn't released.
Almost at once my rope back-released and the rings, flailing about,
smashed a large hole in the canopy and put a medium sized dent in the
wing.

Not an arguement against low-tows with a single glider I agree.

At 09:14 24 February 2014, Don Johnstone wrote:
Can we just not agree that the use of low tow and the non use of CoG
hooks
for aerotowing reduce the likelihood of a kiting event occurring?

The available evidence may show that neither will completely prevent the
occurrence but there is evidence to show that there is an apparent
reduction in occurrence. Complete eradication might be the ideal but
reduction is a start in the right direction.

There is a lot to be said for studying "Best Practice" but you have to
act
on it. If you are used to high tow I would be the first to admit that low
tow looks weird but it is much more stable and requires much less work to
keep the proper position. It appears to me that people are saying that
out
of position in low tow is a much less serious situation that out of
position in high tow (too low is better than too high)

At 09:14 24 February 2014, Don Johnstone wrote:
Can we just not agree that the use of low tow and the non use
of CoG hooks
for aerotowing reduce the likelihood of a kiting event
occurring?

The available evidence may show that neither will completely
prevent the
occurrence but there is evidence to show that there is an
apparent
reduction in occurrence. Complete eradication might be the
ideal but
reduction is a start in the right direction.

There is a lot to be said for studying "Best Practice" but you
have to act
on it. If you are used to high tow I would be the first to admit
that low
tow looks weird but it is much more stable and requires much
less work to
keep the proper position. It appears to me that people are
saying that out
of position in low tow is a much less serious situation that out
of
position in high tow (too low is better than too high)



In my experience it it normal in South Africa to low tow.
Whether the recent fatal tug upset at MGC was intitially in low
tow I have no idea.

At 16:59 24 February 2014, Peter Wyld wrote:
At 09:14 24 February 2014, Don Johnstone wrote:
Can we just not agree that the use of low tow and the non use
of CoG hooks
for aerotowing reduce the likelihood of a kiting event
occurring?

The available evidence may show that neither will completely
prevent the
occurrence but there is evidence to show that there is an
apparent
reduction in occurrence. Complete eradication might be the
ideal but
reduction is a start in the right direction.

There is a lot to be said for studying "Best Practice" but you
have to act
on it. If you are used to high tow I would be the first to admit
that low
tow looks weird but it is much more stable and requires much
less work to
keep the proper position. It appears to me that people are
saying that out
of position in low tow is a much less serious situation that out
of
position in high tow (too low is better than too high)



From another thread, "With limited trim capabilities, it takes quite a bit
of forward stick pressure in level tow in a 2-33". Is this part of the
problem? Could this be one of the causes of kiting incidents? If so should
this be corrected? If a pilot was to let go of the stick would a 2-33 kite?

On Sunday, February 23, 2014 10:40:09 PM UTC-6, GC wrote:
On 24/02/2014 04:23, Dave Nadler wrote:

I'm confused by a couple of statements in this thread...



1) "Low tow prevents kiting"

Doesn't the kiting event often happen in early take-off,

just as glider is leaving the ground, and before low-tow

is established???



I don't know. We haven't had enough recent kiting accidents in Oz to know.





2) "Nose hook prevents kiting"

Didn't we have at least one fatal accident in USA

with a nosehook (L-13 IIRCC)??? Others???

Anybody have any facts (Yes, I know, its RAS, but...)???

I'm not saying nose-hooks don't help, however...



So what ARE you saying? Swallows, summer? Just stirring the pot?



Dave, I'm well aware of the much yada yada on r.a.s. regarding low/high

tow of which you've been part. I'm not going to be drawn into it. As I

said, a lot of it appears to me to be based on personality in the form

of "real men fly high tow - and they do it on CG hooks!"



I only wanted to say that if kiting is a problem, nose hooks and low tow

will reduce it to insignificance. If those practices are not worth

adopting, kiting's not a real problem.



GC



But then, I'm easily confused...

...just keep taking the tablets like I told you...

Thanks,

Best Regards, Dave



So will adding 50 feet to the tow rope!

Zen

At 17:57 24 February 2014, Don Johnstone wrote:
At 16:59 24 February 2014, Peter Wyld wrote:
At 09:14 24 February 2014, Don Johnstone wrote:
Can we just not agree that the use of low tow and the non use
of CoG hooks
for aerotowing reduce the likelihood of a kiting event
occurring?

The available evidence may show that neither will completely
prevent the
occurrence but there is evidence to show that there is an
apparent
reduction in occurrence. Complete eradication might be the
ideal but
reduction is a start in the right direction.

There is a lot to be said for studying "Best Practice" but you
have to act
on it. If you are used to high tow I would be the first to admit
that low
tow looks weird but it is much more stable and requires much
less work to
keep the proper position. It appears to me that people are
saying that out
of position in low tow is a much less serious situation that out
of
position in high tow (too low is better than too high)



From another thread, "With limited trim capabilities, it takes quite a
bit
of forward stick pressure in level tow in a 2-33". Is this part of the
problem? Could this be one of the causes of kiting incidents? If so
should
this be corrected? If a pilot was to let go of the stick would a 2-33
kite?



I've several hundred hours on 2-33's, unless the C of G is well aft the
forward pressure required is not great. The hook is only just under the
nose, it wouldn't kite but it would get out of position high (and probably
off to one side) quite quickly. Any glider, even if trimmed exactly right,
would get out of position very quickly if you let go, a divergent
horizontal 8 is the normal result of letting go.

On Tuesday, February 25, 2014 1:34:31 AM UTC-6, Chris Rollings wrote:

I've several hundred hours on 2-33's, unless the C of G is well aft the

forward pressure required is not great. The hook is only just under the

nose, it wouldn't kite but it would get out of position high (and probably

off to one side) quite quickly. Any glider, even if trimmed exactly right,

would get out of position very quickly if you let go, a divergent

horizontal 8 is the normal result of letting go.


I have several hundred hours in 2-33s (mostly in the back seat giving rides) and I have to disagree - the forward pressure required to maintain normal high tow position at normal (Pawnee) tow speed is significant - and WILL result in a rapid uncommanded climb if it is released (such as in a case when the pilot is distracted). I seriously doubt the 2-33 could be certified today with it's mediocre flying characteristics and sketchy ergonomics.

Some research will reveal articles of long crosscountry repositioning aerotows of 2-33s where a system of bungee cords hooked up to the front stick is described to relieve the pilot of continual forward pressure on the stick.

There have been several cases of 2-33s either climbing or kiting a towplane into the ground. And add to that the technique of "soft releasing" makes towing those beasts even more challenging. First solo of a small 14 year old calls for serious attention to where the glider is going!

I'll stop and take my meds now before going into full rant mode....

Kirk
66

At 13:06 25 February 2014, kirk.stant wrote:
On Tuesday, February 25, 2014 1:34:31 AM UTC-6, Chris Rollings wrote:
=20
I've several hundred hours on 2-33's, unless the C of G is well aft the
=20
forward pressure required is not great. The hook is only just under
the
=20
nose, it wouldn't kite but it would get out of position high (and
probabl=
y
=20
off to one side) quite quickly. Any glider, even if trimmed exactly
righ=
t,
=20
would get out of position very quickly if you let go, a divergent
=20
horizontal 8 is the normal result of letting go.


I have several hundred hours in 2-33s (mostly in the back seat giving
rides=
) and I have to disagree - the forward pressure required to maintain
normal=
high tow position at normal (Pawnee) tow speed is significant - and WILL
r=
esult in a rapid uncommanded climb if it is released (such as in a case
whe=
n the pilot is distracted). I seriously doubt the 2-33 could be certified
t=
oday with it's mediocre flying characteristics and sketchy ergonomics.

Some research will reveal articles of long crosscountry repositioning
aerot=
ows of 2-33s where a system of bungee cords hooked up to the front stick
is=
described to relieve the pilot of continual forward pressure on the
stick.

There have been several cases of 2-33s either climbing or kiting a
towplane=
into the ground. And add to that the technique of "soft releasing"
makes
=
towing those beasts even more challenging. First solo of a small 14 year
o=
ld calls for serious attention to where the glider is going!

I'll stop and take my meds now before going into full rant mode....

Kirk
66


Kirk, I agreed a forward pressure is required on the stick and I admitted
that if the pilot let go of the stick (or failed to maintain that forward
pressure) then the glider would get out of position quite quickly - that is
not a kiting event and it can be stopped at any point by moving the stick
forwards.

Go and try it if you don't believe me.