Almost perfect payout winch launch.

On Sat, 18 May 2013 10:03:48 -0600, Dan Marotta wrote:

Guillotine? How about simply mounting a release mechanism to the back
of the tow vehicle with the release cable within reach of the driver or
observer? That's the way they do it on the dry lake in Nevada and I was
not the least concerned about accepting ground launches. And, of
course, there's always the weak link at the glider end...

The guillotine *is* the winch-end release mechanism. What else can you do
but cut the rope if the glider can't release? Jettisoning the drum and
guides, leaving them swinging beneath the glider isn't a good solution!

And, as others have pointed out, if you're not using a stiff 2-3 metre
strop (4.5mm steel cable inside plastic hose) on the glider's end of the
shock rope, then a hesitation or snatch as the take-off run starts can
wrap the cable round your wheel. That's something that's known to prevent
the glider from releasing its end of the cable.

I've just reviewed the video that started this thread and can't see any
sign that such a strop is in use or any indication that the weak link, if
there is one, at the glider end is correct for the glider. In the UK the
weak link housing is an integral part of the strop and the plastic hose
is colour coded to match the weak link: hence the pilot, or anybody else
at the launch point, can visually check that the correct weak is being
used when the cable is accepted prior to launch.


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

Oops! I was thinking of a straight auto tow. I forgot about the payout
winch part.

You are, of course, correct in the need for a guillotine in this
application.


"Martin Gregorie" wrote in message
...
On Sat, 18 May 2013 10:03:48 -0600, Dan Marotta wrote:

Guillotine? How about simply mounting a release mechanism to the back
of the tow vehicle with the release cable within reach of the driver or
observer? That's the way they do it on the dry lake in Nevada and I was
not the least concerned about accepting ground launches. And, of
course, there's always the weak link at the glider end...

The guillotine *is* the winch-end release mechanism. What else can you do
but cut the rope if the glider can't release? Jettisoning the drum and
guides, leaving them swinging beneath the glider isn't a good solution!

And, as others have pointed out, if you're not using a stiff 2-3 metre
strop (4.5mm steel cable inside plastic hose) on the glider's end of the
shock rope, then a hesitation or snatch as the take-off run starts can
wrap the cable round your wheel. That's something that's known to prevent
the glider from releasing its end of the cable.

I've just reviewed the video that started this thread and can't see any
sign that such a strop is in use or any indication that the weak link, if
there is one, at the glider end is correct for the glider. In the UK the
weak link housing is an integral part of the strop and the plastic hose
is colour coded to match the weak link: hence the pilot, or anybody else
at the launch point, can visually check that the correct weak is being
used when the cable is accepted prior to launch.


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