Winch Launch - Fatal

At 08:24 09 December 2016, Pete Smith wrote:
No, the position changes subtly.

On my cirrus and N2 it is at the lower left of the stick box quadrant,
o
the
N3 in question and later gliders it is in the upper left.

Please read the accident report and its conclusions.

The accident described in the report was not so much of an issue
when Earlier ASW,17, 18,19,20 were designed and built. Same applied
to SH.
The accident is directly related to more powerful winches. The same
situation would develop with less powerful winches but it took much
much longer. There was more of a ground run to recognise the wing
on the ground and the acceleration was much less which meant that
when it went wrong it went wrong much slower with more time to
react. Not so with a modern powerful winch, when the problem occurs
it goes wrong very quickly, probably too quickly for any chance for a
meaningful reaction. What is described has always happened from time
to time, the only difference is that it did not start killing people until

the winches got powerful.

So how dangerous is wench launching compared to aero-tow? I only had enough wench launches to remove the "aero-tow only" off my ticket and that was years ago.

On Friday, December 9, 2016 at 7:45:05 AM UTC-8, Don Johnstone wrote:
At 08:24 09 December 2016, Pete Smith wrote:
No, the position changes subtly.

On my cirrus and N2 it is at the lower left of the stick box quadrant,
o
the
N3 in question and later gliders it is in the upper left.

Please read the accident report and its conclusions.

The accident described in the report was not so much of an issue
when Earlier ASW,17, 18,19,20 were designed and built. Same applied
to SH.
The accident is directly related to more powerful winches. The same
situation would develop with less powerful winches but it took much
much longer. There was more of a ground run to recognise the wing
on the ground and the acceleration was much less which meant that
when it went wrong it went wrong much slower with more time to
react. Not so with a modern powerful winch, when the problem occurs
it goes wrong very quickly, probably too quickly for any chance for a
meaningful reaction. What is described has always happened from time
to time, the only difference is that it did not start killing people until

the winches got powerful.

Pretty dangerous for the wench, I imagine. Depending on her weight, you might need a weak link.

The Soaring Safety Foundation (US) should have the best info on this https://www.soaringsafety.org/ This is a very good resource for safety training. There have been some European and UK studies out there since they tend to winch more than US. Aero-tow kills more tow pilots than winching kills wenches.

At 16:19 09 December 2016, Jonathan St. Cloud wrote:
So how dangerous is wench launching compared to aero-tow? I only
had enough
wench launches to remove the "aero-tow only" off my ticket and that
was
years ago.

I do not have the figures but my answer would be as safe as any other
method of launching.
I do not know but I suspect the number of winch launches in the UK
runs to many thousands per year. Accidents like the one described are
very rare, the last recorded 4 years ago.
Aerotows tend to be more of a gotcha for tuggies but there are a lot
less of them so they are even less frequent.
Bungee launching tends to involve lighter gliders but has it's share of
accidents, very few fatal.
Winching is not for the unwary and less forgiving of errors than other
methods, more so since the introduction of modern powerful winches
with the ability to accelerate very very quickly.

......hmmmmm, I would say that those missing figures are fairly important in forming a consensus on that. We lost a passenger when a winch went bad in a two-placer a few years back. Pilot (a good one) was seriously injured. And, on the other side, a high-time pilot was killed after a PTT in Arizona http://www.kathrynsreport.com/2014/0...izona.html?m=1

(Another issue that needs more facts, maybe from the SSF: Are "we" putting passengers at more risk by loading them in the front seat? They are, of course, often the first ones to the scene of an accident.)

Wench launching can be very dangerous, especially if she's heavy and
your aim is poor...

On 12/9/2016 9:19 AM, Jonathan St. Cloud wrote:
So how dangerous is wench launching compared to aero-tow? I only had enough wench launches to remove the "aero-tow only" off my ticket and that was years ago.

On Friday, December 9, 2016 at 7:45:05 AM UTC-8, Don Johnstone wrote:
At 08:24 09 December 2016, Pete Smith wrote:
No, the position changes subtly.

On my cirrus and N2 it is at the lower left of the stick box quadrant,
o
the
N3 in question and later gliders it is in the upper left.

Please read the accident report and its conclusions.

The accident described in the report was not so much of an issue
when Earlier ASW,17, 18,19,20 were designed and built. Same applied
to SH.
The accident is directly related to more powerful winches. The same
situation would develop with less powerful winches but it took much
much longer. There was more of a ground run to recognise the wing
on the ground and the acceleration was much less which meant that
when it went wrong it went wrong much slower with more time to
react. Not so with a modern powerful winch, when the problem occurs
it goes wrong very quickly, probably too quickly for any chance for a
meaningful reaction. What is described has always happened from time
to time, the only difference is that it did not start killing people until

the winches got powerful.

--
Dan, 5J

Damn autocorrect meant wrench launching.
On Friday, December 9, 2016 at 12:02:52 PM UTC-8, Dan Marotta wrote:
Wench launching can be very dangerous, especially if she's heavy and
your aim is poor...

On 12/9/2016 9:19 AM, Jonathan St. Cloud wrote:
So how dangerous is wench launching compared to aero-tow? I only had enough wench launches to remove the "aero-tow only" off my ticket and that was years ago.

On Friday, December 9, 2016 at 7:45:05 AM UTC-8, Don Johnstone wrote:
At 08:24 09 December 2016, Pete Smith wrote:
No, the position changes subtly.

On my cirrus and N2 it is at the lower left of the stick box quadrant,
o
the
N3 in question and later gliders it is in the upper left.

Please read the accident report and its conclusions.

The accident described in the report was not so much of an issue
when Earlier ASW,17, 18,19,20 were designed and built. Same applied
to SH.
The accident is directly related to more powerful winches. The same
situation would develop with less powerful winches but it took much
much longer. There was more of a ground run to recognise the wing
on the ground and the acceleration was much less which meant that
when it went wrong it went wrong much slower with more time to
react. Not so with a modern powerful winch, when the problem occurs
it goes wrong very quickly, probably too quickly for any chance for a
meaningful reaction. What is described has always happened from time
to time, the only difference is that it did not start killing people until

the winches got powerful.

--
Dan, 5J

On Friday, December 9, 2016 at 2:29:56 PM UTC-6, Jonathan St. Cloud wrote:

Damn autocorrect meant wrench launching.

Now autocorrect has you throwing tools about!

Steve

On Tuesday, December 6, 2016 at 9:15:05 AM UTC-5, Jock Proudfoot wrote:


My early flying was nearly all launched by winch; the winches
in the 60s were pretty anaemic.
Nevertheless, the standard practice was to take up cable slack
till it was pretty straight, so the initial acceleration was
directed along the glider axis. this would remove the roll couple as described in the report.
More recently, experience at Bristol GC and the Mynd was like
a superbungee launch and I admit to some concern about the elevator
power to cope with the pitchup.

It would seem that initial acceleration should be moderated.

The PTT problem is unknown to me, but I presume it must mean
passenger temper tantrum.

JMF

I just launched a wrench the other day trying to get the *&#$@ retaining bolt out of the rudder of a Grob Twin Astir. Actually pretty cathartic.

Not to make light of this tragic situation, but a little humor hopefully won't hurt...

P3