Wing Launch - Can it pull your wings off?

Derek C wrote:
The consequence of using a 10% weaker link would be a greater chance
of a broken weak link and a failed launch, which might be hazardous in
itself under some circumstances.

No, never! A cable brake is routine and *never* hazardous in *any*
circumstances. If it is, then something in your operation is seriously
flawed.

But a cable brake (or weak link brake) is always an annoyance, as it
interrupts the operation.

On Aug 14, 11:30*am, John Smith wrote:
Derek C wrote:
The consequence of using a 10% weaker link would be a greater chance
of a broken weak link and a failed launch, which might be hazardous in
itself under some circumstances.

No, never! A cable brake is routine and *never* hazardous in *any*
circumstances. If it is, then something in your operation is seriously
flawed.

Depends on the size and nature of the airfield. Our site at Lasham in
the UK is large and flat, and gives you a wide range of options after
a winch launch failure. I have flown at a small sloping German site
where they launched without a weak link because having a weak link
failure was considered a serious hazard. Having said that the speed
control and quality of their winch launches was very good.

Derek C

On Aug 14, 3:30*am, John Smith wrote:

No, never! A cable brake is routine and *never* hazardous in *any*
circumstances...

I do envy your faith in the ubiquity of human competence.

Thanks, Bob K.

Derek C wrote:
On Aug 14, 11:30 am, John wrote:

No, never! A cable brake is routine and *never* hazardous in *any*
circumstances. If it is, then something in your operation is seriously
flawed.

Depends on the size and nature of the airfield. Our site at Lasham in
the UK is large and flat, and gives you a wide range of options after
a winch launch failure. I have flown at a small sloping German site
where they launched without a weak link because having a weak link
failure was considered a serious hazard.

Hmmmmm... I've experienced firsthand a fair number of rope brakes on the
winch (but interestingly not a single weak link break), and hence
consider a rope break pretty much SOP when winching. So I'm not sure I'd
want to fly at that German site. I have no problem with an airfield
where a cable brake puts me in a difficult situation which requires
special procedures but a cable brake shall never be hazardous.

On Aug 14, 9:36*am, Bob Kuykendall wrote:
On Aug 14, 3:30*am, John Smith wrote:

No, never! A cable brake is routine and *never* hazardous in *any*
circumstances...

I do envy your faith in the ubiquity of human competence.

Thanks, Bob K.

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.

Breaks should be totally routine and pilots should handle them
instinctively.

On Aug 13, 12:00*pm, bildan wrote:

If your glider was certified with an Approved Flight Manual, as all
JAR-22 gliders are, FAR's require you to operate in compliance with
that manual.

Please be more specific. What particular FAR requires me to operate
my experimental (racing and exhibition) ASW-28 in compliance with the
flight manual?

The Experimental Operating Limitations contain specific extracts from
the flight manual that I am required to comply with. If content of
the flight manual was not extracted and included in the Experimental
Operating Limitations I am not aware that is has any regulatory
significance.

The flight manual extracts included in my limitations relate only to
maximum gross weight, allowable CG range, and maximum operating
speeds.

Sure, I recognize that it would be good practice to read and comply
with the flight manual, but that is not the same as being required to
do so by federal regulation.

Andy

On Aug 14, 5:28*pm, Andy wrote:
On Aug 13, 12:00*pm, bildan wrote:

If your glider was certified with an Approved Flight Manual, as all
JAR-22 gliders are, FAR's require you to operate in compliance with
that manual.

Please be more specific. *What particular FAR requires me to operate
my experimental (racing and exhibition) ASW-28 in compliance with the
flight manual?

The Experimental Operating Limitations contain specific extracts from
the flight manual that I am required to comply with. *If content of
the flight manual was not extracted and included in the Experimental
Operating Limitations I am not aware that is has any regulatory
significance.

The flight manual extracts included in my limitations relate only to
maximum gross weight, allowable CG range, and maximum operating
speeds.

Sure, I recognize that it would be good practice to read and comply
with the flight manual, but that is not the same as being required to
do so by federal regulation.

Andy

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

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.

On 8/14/2010 8:17 AM, Derek C wrote:
On Aug 14, 11:30 am, John wrote:
Derek C wrote:
The consequence of using a 10% weaker link would be a greater chance
of a broken weak link and a failed launch, which might be hazardous in
itself under some circumstances.

No, never! A cable break is routine and *never* hazardous in *any*
circumstances. If it is, then something in your operation is seriously
flawed.

Depends on the size and nature of the airfield. Our site at Lasham in
the UK is large and flat, and gives you a wide range of options after
a winch launch failure. I have flown at a small sloping German site
where they launched without a weak link because having a weak link
failure was considered a serious hazard. Having said that the speed
control and quality of their winch launches was very good.

Derek C

Out of genuine curiosity, can you share more details of "small sloping...site"?

I have difficulty imagining a winch site unsuitable for either a straight
ahead landing following an 'early-early' launch problem not also suitable for
a 360-to-a-return-at-the-launch-point for a 'later-in-time' launch problem. I
am assuming a 'reasonably powered winch' of course, which I imagine is the
German norm. Short of an anemic winch with the winch/line stashed down a road
in a copse of woods, my imagination fails me here.

My experience in the western U.S. (generally 5000' msl) is any field
considered 'distance-suitable' for (even marginal) aerotowing is - in a
launch-emergency sense - far more 'emergency-option-friendly' than aerotowing,
because you never get dragged at low altitude over completely unlandable
terrain...which is definitely *not* the case in these parts with aerotowing.
Are there folks winch launching from postage-stamp-sized-fields surrounded by
unlandable terrain using a beyond-the-boundary-winch?

Curiously,
Bob W.

On Aug 14, 3:43*pm, bildan 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.

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 don't much hold with either "always" or "never."

All dangers are relative. The added hazards of a cable break may be
fairly low, but I am confident that rigorous analysis will demonstrate
them to be statistically significant.

Even the most competent pilots have their off days and off minutes,
and the intersection of those times and trying circumstances can and
too often will be troublesome.

Note that I do not argue that winch launching is to any great degree
dangerous. That is not the case. I believe that, when executed
conscientiously, winch launching can equal or better the safety record
of aerotow.

What I do argue is that every soaring operation entails non-trivial
risk, and that those risks can only be greater when things do not go
as planned or expected.

Thanks, Bob K.

On Aug 14, 5:24*pm, John Smith wrote:
Derek C wrote:
On Aug 14, 11:30 am, John *wrote:
No, never! A cable brake is routine and *never* hazardous in *any*
circumstances. If it is, then something in your operation is seriously
flawed.

Depends on the size and nature of the airfield. Our site at Lasham in
the UK is large and flat, and gives you a wide range of options after
a winch launch failure. I have flown at a small sloping German site
where they launched without a weak link because having a weak link
failure was considered a serious hazard.

Hmmmmm... I've experienced firsthand a fair number of rope brakes on the
winch (but interestingly not a single weak link break), and hence
consider a rope break pretty much SOP when winching. So I'm not sure I'd
want to fly at that German site. I have no problem with an airfield
where a cable brake puts me in a difficult situation which requires
special procedures but a cable brake shall never be hazardous.

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. The
alternatives were a controlled crash into a vineyard or a water
landing on the local river.

I have also winch launched at a very small UK site called Sandhill
Farm near Shrivenham in Wiltshire, which wasn't much better. At
certain heights you only option was to land in one of the surrounding
fields. They have since given up winch launching as they felt that the
risk to reward (700-800ft launches) ratio was too great.

The only problem with winch launching (of which I am a great fan) is
that you need a reasonable large airfield to get decent heights and to
do it safely without presenting pilots with extremely critical
judgement decisions in the event of a launch failure.

Derek C