Our ropes are 200 ft long so the jig would either have to be very large or
the rope would need to mounted and dismounted numerous times.

I've had three rope breaks in the past three years while flying the tug at
Moriarty - never before in the previous 20+ years. Two were the fault of
the glider pilot horribly mishandling the glider and one of those resulted
in the rope being wrapped around the wing of the HP-14. The wing was cut
back to the spar before the rope broke. The third rope break had one of
our instructors flying his Libelle and the rope broke at about 300' AGL on
tow. He and I were both surprised and he handled the emergency perfectly.
The rope broke about 10 feet in front of the glider, probably in an area of
high wear.

We inspect our ropes daily in the morning and during operations throughout
the day. If sufficient wear is noted, the rope is replaced. More often
it's the weak link which gets replaced due to abrasion with the pavement.
We use the top half of drinking water bottles, slipped over the weak link,
and wrapped heavily with duct tape. These work well, but, if the tug lands
such that the protector hits the end of the runway, it's ripped off. We
then replace the weak link.

(Whew!)


"son_of_flubber" wrote in message
...
On Thursday, November 14, 2013 10:50:46 AM UTC-5, Dan Marotta wrote:
Are we gonna fly today or will the eight hour test and evaluation session

use up all available daylight?

Good point. Time is limited.

If an elongation test would detect weakening ropes, you would only need to
do it once a week or so because many forms of degradation is gradual. If
you had a permanent jig for testing elongation, it would take 10 minutes.
Or you could test the ropes at the beginning of wave season when you know
they are gonna get stressed (or even better, you could replace your ropes at
the beginning of wave season).

Ever have a rope break at Moriarty? I know that you have a lot of grit.