On 9/9/2016 3:58 PM, Bob T wrote:
Snip

A really scary comment in the NTSB final report: "Postaccident examination
of the glider's release system revealed that it was missing a spring, which
likely resulted in the cable not engaging in the detent and caused the
premature release from the tow line."
http://www.ntsb.gov/_layouts/ntsb.av...04X34426&key=1

It was a bumpy day. I took off about 10 minutes of Bob and hit strong
turbulence and sink over the last few hundred yards of the runway. My 200
foot countdown took much longer than usual, but, as I continued on tow,
finally got up and found a good thermal and left the area, unaware of the
crash that had occurred behind me.

Bob was a very experienced jet pilot with thousands of hours, but had just
gotten into gliding and had only recently purchased the glider. Having his
glider release itself because of a faulty release mechanism in turbulence
only 100 ft. AGL and only desert trees ahead, our newbe pilot made the
unfortunate fatal decision to turn back and spun in.

When was the last time YOU had your release checked by a professional???


"Right on!" regarding "known-good release health."

Philosophical agreement aside...if (big "if") the release was an original
Aerotek release, I've a hard time getting my head around the NTSB's "missing
spring" possibility (though if it happens, it must be possible).

So far as I'm aware, every Zuni left the factory with a clone of Dick
Schreder's dirt-simple HP release (used in every HP I've examined, including
up to HP-16's and one HP-18).

The original release uses a single spring, easily visible (assuming the
cockpit-side of the release wasn't subsequently enclosed by some sort of
doghouse). But more to the point, without the spring the original release
simply doesn't *work* properly - as in, requiring active, precise-and-fiddly,
action (on-the-rope-connnector-person's-part), to make a tension-holding
connection. I know because I tried both my HP-14 and Zuni (S/N 3)releases
sans-spring, on the ground, just out of curiosity. As it was, even with a
properly functioning release, part of my pre-launch routine was describing to
(almost!) every rope-connecting-person how to connect the rope (a task Joe
Pilot could not assist with from within the cockpit). Whereas having "Joe
Average Connector Person" make a successful connection with a functioning
spring is "verbally trivial" from Joe Pilot's perspective, I doubt I could
have talked through J.A.C. Person into making a(n apparently) secure
connection in the absence of a spring. Memory says that doing so requires two
hands, one with access to the interior/cockpit side of the release.

Now if the spring failed or somehow came loose, I'd expect an immediate back
release the instant the rope lost tension for any reason.

Bob W.