Wing Launch - Can it pull your wings off?

On Aug 17, 4:50*am, Derek C wrote:
On Aug 15, 7:51*pm, Andreas Maurer wrote:



On Sun, 15 Aug 2010 10:12:03 +0200, John Smith

wrote:
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?

The timing.

With such a short field it might be necessary to execute this teardrop
circuit at very low altitude because it's not possible anymore to land
straight-on.

Little error margin for finding the right compromise between executing
the turn ionto final at a healthy altitude and not too close to the
airfield.

It's definitely more relaxed to execute this teardrop circuit at
300ft+.

Cheers
Andreas

Here is a video of a German pilot getting a teardrop circuit wrong
after an 80 metre (about 250ft) cable break:

*http://www.youtube.com/watch?v=_xCct...os=zqLm5HhNvPc

Derek C

Andreas, Derek, your posts reveal, in great detail and in ways you
obviously don't realize, just how screwed up many UK winch operations
are. The real danger for US operations is if they take your posts as
"normal" operations - they aren't. I hope they will ignore the UK and
study Continental, specifically German operations instead.

Dyneema doesn't just "break", clumsy, incompetent operations break
it. Clearly your Dyneema is being damaged by poor winch design and
rough handling. You don't let Dyneema "fall", you pull it to the
winch.

On Aug 17, 4:50*am, Derek C wrote:
On Aug 15, 7:51*pm, Andreas Maurer wrote:



On Sun, 15 Aug 2010 10:12:03 +0200, John Smith

wrote:
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?

The timing.

With such a short field it might be necessary to execute this teardrop
circuit at very low altitude because it's not possible anymore to land
straight-on.

Little error margin for finding the right compromise between executing
the turn ionto final at a healthy altitude and not too close to the
airfield.

It's definitely more relaxed to execute this teardrop circuit at
300ft+.

Cheers
Andreas

Here is a video of a German pilot getting a teardrop circuit wrong
after an 80 metre (about 250ft) cable break:

*http://www.youtube.com/watch?v=_xCct...os=zqLm5HhNvPc

Derek C

Yes, and it's obviously a landing accident, not a winch accident. The
pilot had a perfect opportunity to make a safe landing and failed to
do so.

On Aug 17, 10:16*am, bildan wrote:
Andreas, Derek, your posts reveal, in great detail and in ways you
obviously don't realize, just how screwed up many UK winch operations
are. *The real danger for US operations is if they take your posts as
"normal" operations - they aren't. *I hope they will ignore the UK and
study Continental, *specifically German operations instead.

I think I must have lost track of the plot. When did Andreas move to
UK?

Andy

On Tue, 17 Aug 2010 10:19:10 -0700 (PDT), bildan
wrote:

Yes, and it's obviously a landing accident, not a winch accident. The
pilot had a perfect opportunity to make a safe landing and failed to
do so.

Hi Bill,

could you please post the complete clip of the whole flight from the
(supposed) cable break?
Looks like you have more information than this 15-second clip on
YouTube.


Thanks in advance
Andreas

On Tue, 17 Aug 2010 10:16:48 -0700, bildan wrote:

Dyneema doesn't just "break", clumsy, incompetent operations break it.
Clearly your Dyneema is being damaged by poor winch design and rough
handling. You don't let Dyneema "fall", you pull it to the winch.

Its rather difficult to pull the top section in after the rope has broken.

I agree about not crossing the ropes though: good tow-out procedure and
correct choice of which rope to use first should prevent to ropes from
becoming crossed.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

On Tue, 17 Aug 2010 07:25:42 -0700, Derek C wrote:

This particular video probably should have an 18 rating though!

Why?

It shows the effect of a combination of a strong wind gradient on a low,
slow turn as something to avoid, but there is no obvious blood & guts
such as might turn the stomach of a delicate young person of the under 18
persuasion.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

On 8/16/2010 9:19 AM, Andreas Maurer wrote:
On Sun, 15 Aug 2010 19:56:16 -0700 (PDT),
wrote:



That's basically what you get from the new winch
designs. Easier, safer launches with greater performance.
Nope.


Dyneema is an exception. It has been proven safer than steel cable by
every industry that has adopted it - there's lots of industrial safety
data on that. Besides being safer, it's just way nicer to work with.

Hmmm... on my airfield (we were the first ones to use Dyneema) we
already had more than only a couple of incidents that were directly
related to the use of Dyneema and wouldn't have happened with steel
cable. We came to the conclusion that -at least on my airfield- steel
cable offers more advantages than disadvatages than Dyneema.

Cheers
Andreas


is the crucial issue abrasion, or UV degradation?

Brian W

On Tue, 17 Aug 2010 16:51:29 -0500, brian whatcott
wrote:


is the crucial issue abrasion, or UV degradation?

I guess it's a combination of less-than-perfect winch design, not
completely level airfield and using already damaged cable that results
in shorter than expected lifespan of the Dyneema cable and a
comparably high number of cable breaks.

One problem is that in case of a cable break the latter often falls
into a little wood from which recovery is difficult (pulling the cable
trough the wood usually damages it sufficiently that it needs
replacement).


But our main problem is completely different: As I already wrote in
another posting in this thread, the Dyneema cable gets blown all over
the place in case of a cable break with even a medium crosswind,
forcing us to cease all operation till the cable has definitely been
cleared out of the way.
We've been badly surprised several times about how long the Dyneema
cable stays in the air and how far it can be blown.

Andreas

On Aug 17, 6:16*pm, bildan wrote:
On Aug 17, 4:50*am, Derek C wrote:





On Aug 15, 7:51*pm, Andreas Maurer wrote:

On Sun, 15 Aug 2010 10:12:03 +0200, John Smith

wrote:
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?

The timing.

With such a short field it might be necessary to execute this teardrop
circuit at very low altitude because it's not possible anymore to land
straight-on.

Little error margin for finding the right compromise between executing
the turn ionto final at a healthy altitude and not too close to the
airfield.

It's definitely more relaxed to execute this teardrop circuit at
300ft+.

Cheers
Andreas

Here is a video of a German pilot getting a teardrop circuit wrong
after an 80 metre (about 250ft) cable break:

*http://www.youtube.com/watch?v=_xCct...os=zqLm5HhNvPc

Derek C

Andreas, Derek, your posts reveal, in great detail and in ways you
obviously don't realize, just how screwed up many UK winch operations
are. *The real danger for US operations is if they take your posts as
"normal" operations - they aren't. *I hope they will ignore the UK and
study Continental, *specifically German operations instead.

Dyneema doesn't just "break", clumsy, incompetent operations break
it. *Clearly your Dyneema is being damaged by poor winch design and
rough handling. *You don't let Dyneema "fall", you pull it to the
winch.- Hide quoted text -

- Show quoted text -

I note from his profile that Andreas has a German email address, so I
guess that he lives and flies in Germany!

In fact German and UK practices are pretty similar, apart from the
German land line telephone requirement for communication between the
launch point and the winch. The standard European winch used to be the
German Tost, but it is now becoming the British Skylaunch. The French
National Gliding Centre have recently ordered two turbo-diesel engined
Skylaunch 2 winches, with one already delivered and in service.

Derek C

On Aug 17, 6:16*pm, bildan wrote:
On Aug 17, 4:50*am, Derek C wrote:





On Aug 15, 7:51*pm, Andreas Maurer wrote:

On Sun, 15 Aug 2010 10:12:03 +0200, John Smith

wrote:
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?

The timing.

With such a short field it might be necessary to execute this teardrop
circuit at very low altitude because it's not possible anymore to land
straight-on.

Little error margin for finding the right compromise between executing
the turn ionto final at a healthy altitude and not too close to the
airfield.

It's definitely more relaxed to execute this teardrop circuit at
300ft+.

Cheers
Andreas

Here is a video of a German pilot getting a teardrop circuit wrong
after an 80 metre (about 250ft) cable break:

*http://www.youtube.com/watch?v=_xCct...os=zqLm5HhNvPc

Derek C

Andreas, Derek, your posts reveal, in great detail and in ways you
obviously don't realize, just how screwed up many UK winch operations
are. *The real danger for US operations is if they take your posts as
"normal" operations - they aren't. *I hope they will ignore the UK and
study Continental, *specifically German operations instead.

Dyneema doesn't just "break", clumsy, incompetent operations break
it. *Clearly your Dyneema is being damaged by poor winch design and
rough handling. *You don't let Dyneema "fall", you pull it to the
winch.- Hide quoted text -

- Show quoted text -

I note from his profile that Andreas has a German email address, so I
guess that he lives and flies in Germany!

In fact German and UK practices are pretty similar, apart from the
German land line telephone requirement for communication between the
launch point and the winch. The standard European winch used to be the
German Tost, but it is now becoming the British Skylaunch. The French
National Gliding Centre have recently ordered two turbo-diesel engined
Skylaunch 2 winches, with one already delivered and in service.

Derek C