Wing Launch - Can it pull your wings off?

Bob Kuykendall wrote:
Breaks should be totally routine and pilots should handle them
instinctively.

I'm sorry, Bill, I'm still not buying it. It's the word "never" that
rings my bell.

I stand by my words: A rope break shall *never* be hazardous as such. Of
course, every pilot may screw up, but that's a completely different
question and not limited to rope breaks.

Derek C wrote:
The site in question is a narrow strip 800 metres long, sloping
downhill at about 1 in 10, on top of a hill and totally surrounded by
small unlandable vineyards. They always launched downhill,
irrespective of wind direction. Once above about 200ft, but below
circuit height, the only cable break option to get back onto site was
a 180 degree turn (teardrop circuit) to land back uphill.

And where's the problem?

On Aug 15, 2:23*pm, Bob Whelan wrote:
Are there folks winch launching from postage-stamp-sized-fields surrounded by
unlandable terrain using a beyond-the-boundary-winch?

The site where I converted to winch launching was like that. It's
"Jury Hill", at Greytown, near Wellington NZ.

There is a quite long north/south runway, but the interesting
conditions are often in westerly winds. The westerly runway starts
from the southern end of the main runway and at the time I was flying
there had a length of around 300 - 400 m. The winch run was something
like 1200 m with the remainder of the distance to the winch crossing a
mixture of swamp and low "sand dunes" (not actually sand, but
similarly lumpy). The cable retrieve vehicle used a not terribly
straight path through the lumps, including crossing a farm track and
one or two small streams.

With a glider with good brakes (e.g. Ka7, ASK13) and a bit of a
headwind (and you wouldn't use that runway unless there was too much
crosswind for the other one) you could land straight ahead from a
cable break at 200 or 250 ft and make some kind of circuit from 200 ft
or less, so there was always either one good option or else two
reasonable ones for the same runway, plus the option of simply turning
right 90 degrees onto the 1000+ m runway and land with a crosswind.

Bias disclaimer -
I learned to fly on a winch. First two flights in gliders were aerotow -
Never took an aero tow again until 3 years post solo. So you might say I
have a primacy bias towards winch feeling right and consequently
perceived as safe.

That said -
The BGA statistics, taken from the UK and continental Europe,
unfortunately are unequivocal that winch launching was responsible for a
disproportionate number of fatalities. Note I said disproportionate - so
corrected for the relatively higher percentage of winch launches.

Having run a formal program to remove unsafe practices and to understand
the dynamics of what happens when it goes wrong, the recent statistics
are very good. It turns out that winch launching IS actually very safe
as long as best practice is followed. AND as long as everyone involved -
including the winch driver knows what to do.

So - anyone who considers a launch failure to be an emergency, is in
need of some "upskilling" it should be "ops-normal". But, to say that a
cable break is never dangerous is denial. Any cable break involves
danger - handling it correctly should be standard unexciting practice -
but denial of risk is the most dangerous thing in flying...

For me - there are few things more stressful in all my glider flying
that being dragged at low level by some anaemic tug - full of water -
over the "select a hazard of your choice - rocks, shacks, water, trees,
power lines..."

Conversely - winch launching lets you get into trouble VERY quickly.

Whichever way you launch , there is no substitute for awareness and
having a plan for what to do if things go wrong. For my part - If I have
to chose a launch emergency I would far rather have the winch failure -
you generally have more alternatives for mitigating that risk.

Bruce

On 2010/08/15 6:22 AM, Bob Kuykendall wrote:
On Aug 14, 3:43 pm, wrote:

Bob, John Smith is correct. If a cable break appears hazardous for a
particular pilot, then that pilot is seriously under-trained. Almost
90% of winch training is directed to safely handling rope breaks and a
good winch instructor just won't sign a pilot off until a safe outcome
is assured. Note that I said "rope" since steel cable is no longer
insurable in the US.
Snip

--- news://freenews.netfront.net/ - complaints: ---

"The BGA statistics, taken from the UK and continental Europe,
unfortunately are unequivocal that winch launching was responsible for a
disproportionate number of fatalities"

BGA statistics on Continental Europe are seriously in error. You're
just trying to say that everybody else is a bad as the UK - they
aren't.

I have obtained accident statistics from Germany for 2009. More than
1.5 million winch launches resulted in just 17 accidents (13 of which
were really landing accidents since the glider was in a position for a
safe landing with good height and airspeed.) There were three
fatalities.

That's an absolutely extraordinary safety record - far, far better
than aero tow in the US or winch launch in the UK. The SSF says the
US lost 12 people on aero tow in 2009.

If winch launch is done competently, as it is in Germany, it's orders
of magnitude safer than aero tow as practiced in the US. I strongly
advise adopting the training methods and operating techniques used in
Germany.

John Smith's point is not about the infallibility of pilots, (fools
will find a way) it's that a winch operation should never put a pilot
in a situation where more than basic flying ability is required to
recover from a rope break. This goes for aero tow operations as well.

As an instructor, I can tell if a pilot has to think through a
recovery or is doing it instinctively. I train until it's
instinctive. If they maintain that level of competency, rope breaks
will never be a hazard for them.

On Aug 14, 6:37 pm, bildan wrote:

Every E&R Experimental operations limitations letter I've seen
requires operation in compliance with the AFM.

I can find no such requirement in mine. Does anyone else operating
experimental (racing/exhibition) have this requirement in their
operating limitations? If so, would you please email me a copy.

FAR Part 91.9(a) requires operation in compliance with an AFM if one is part of the
original airworthiness certification. (i.e JAR-22)

My operating limitations do not require compliance with all of part
91. They reference very specific sections. In reference to 91.9 they
state in para 21 - This aircraft shall contain the placards.,
markings, etc. required by 91.9.

91.9 (a) states

a) Except as provided in paragraph (d) of this section, no person may
operate a civil aircraft without complying with the operating
limitations specified in the approved Airplane or Rotorcraft Flight
Manual, markings, and placards, or as otherwise prescribed by the
certificating authority of the country of registry.

It is my interpretation that "or as otherwise prescribed by the
certificating authority of the country of registry" means that the
details of the operating limitations specified by FAA (the
certificating authority in the country of registry) take precedence.
Those operating limitations make specific reference to the requirement
for placards and markings but make no reference to the AFM.

Why would the operating limitations pick out specific sections of part
91, and specific data from the AFM, for inclusion unless only those
included references/restrictions were applicable? It would be far
simpler to state that the aircraft is required to operate in
accordance with Part 91.

I'm very sure (based on FAA interpretations) if an E&R airworthiness
certificate is issued for a glider which had a standard airworthiness
certificate with AFM in it's country of origin, the mere issuance of a
US E&R airworthiness certificate does not excuse the owner of the
glider from compliance with the AFM.

Can you please give me references to, or email copies of, any
interpretation that requires compliance with the AFM when the
operating limitations do not. Do those interpretations also relate to
compliance with an approved maintenance manual?

thanks

Andy

On Sun, 15 Aug 2010 07:34:22 -0700, bildan wrote:

As an instructor, I can tell if a pilot has to think through a recovery
or is doing it instinctively.

As a pilot, one never knows whether one will get to the top of a winch
launch. During my training, at HUSBOS, simulated cable breaks were very
much in evidence. Recovery does become instinctive, and rather fun.

--
Alex

The debate on the merits and technicalities of winch launching will
rage on ad infinitum as it has for years in the winch newsgroups.
However, in terms of winch safety the statistics for the UK and
Germany are very different. Winch launching on the Continent shows a
much lower accident rate than the British experience. In other cases a
mishandling of statistics paints an out-of-focus picture. For example
an article published in Soaring magazine a while back quoted
statistics from a very small sample group to make a point about winch
safety. The article was very much off-base and was a poor piece of
work based on insufficient data. The German study, however, does
appropriately apply statistical analysis to an appropriate sample
size.

I am surprised that no one has asked the question: Is it sensible to
winch launch a 50-year old wooden glider, in which the type has had
reported structural issues? A quick look at the UK winch accident
records seems to involve a disproportionate number of old gliders and
marginal winch equipment. Having flown at winch operations in both the
UK and Germany, my limited experience has been that the Germans
(generally speaking) are operating with better equipment than may be
the case in the UK. (Yes, of course there are some operations in the
UK with all the latest stuff and good procedures. But on the grand
average maybe not as good as on the Continent.)

So when the original question is asked, the first context should be –
Really? Winch launching 50-year old wood wing gliders?

Bob

On Aug 15, 5:03*pm, RL wrote:
The debate on the merits and technicalities of winch launching will
rage on ad infinitum as it has for years in the winch newsgroups.
However, in terms of winch safety the statistics for the UK and
Germany are very different. Winch launching on the Continent shows a
much lower accident rate than the British experience. In other cases a
mishandling of statistics paints an out-of-focus picture. For example
an article published in Soaring magazine a while back quoted
statistics from a very small sample group to make a point about winch
safety. The article was very much off-base and was a poor piece of
work based on insufficient data. *The German study, however, does
appropriately apply statistical analysis to an appropriate sample
size.

I am surprised that no one has asked the question: Is it sensible to
winch launch a 50-year old wooden glider, in which the type has had
reported structural issues? * A quick look at the UK winch accident
records seems to involve a disproportionate number of old gliders and
marginal winch equipment. Having flown at winch operations in both the
UK and Germany, my limited experience has been that the Germans
(generally speaking) are operating with better equipment than may be
the case in the UK. (Yes, of course there are some operations in the
UK with all the latest stuff and good procedures. But on the grand
average maybe not as good as on the Continent.)

So when the original question is asked, the first context should be –
Really? Winch launching 50-year old wood wing gliders?

Bob

If gliders are not capable of being winch launched using the correct
weak link, they are not airworthy. We winch launch vintage gliders all
the time in the UK as part of a very active Vintage Glider movement.


Derek C

The debate on the merits and technicalities of winch launching will
rage on ad infinitum as it has for years in the winch newsgroups.
However, in terms of winch safety the statistics for the UK and
Germany are very different. Winch launching on the Continent shows a
much lower accident rate than the British experience. In other cases a
mishandling of statistics paints an out-of-focus picture. For example
an article published in Soaring magazine a while back quoted
statistics from a very small sample group to make a point about winch
safety. The article was very much off-base and was a poor piece of
work based on insufficient data. *The German study, however, does
appropriately apply statistical analysis to an appropriate sample
size.

Glad you brought this up, I also didn't like that article. My main
problem was less the sample data size, but rather the timeframe it
represented. It lumps all the statistics going back to the 60s into
single figures when it should really be separated into at least 2 or 3
different 'eras' for that same timeframe, when various gliding
authorities and groups identified common problems and implemented
standardized solutions that were game changers. Also, modern winches
are orders of magnitude more powerful and more importantly quite
controllable. That combined with material advances (UHMW etc) further
separate modern winching from it's roots.

Modern winching is pretty much a science and has come a long way since
the 60s so it does not do the soaring community (US at least...) a
favor to combine it all into single raw statistics cause it paints a
negative biased picture based on irrelevant data. It would be like
combining accident data from the era before seatbelts and airbags with
modern car accident statistical data, and then using that to form
statistics/articles to help potential future drivers decide how safe
cars are.

-Paul