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

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

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