AT releases
Moderator: CHGPA BOD
-
- Posts: 304
- Joined: Wed Feb 09, 2005 8:50 am
AT releases
Damn, Hugh stole a lot of my thunder before I could post but...
The two point release I developed the better part of four years ago blows you
off tow with stored energy, is actuated with minimal force by sliding your
hand inboard along the basetube a couple of inches, and is lighter and
magnitudes cleaner than any other two point system out there. It restores virtually
all of the full point of performance that Rob Kells estimates the external cable
housing crap sucks out of your faired downtube and the transmission element
can't bind in such housing. It is also, as far as anyone has yet been able to
determine, one hundred percent reliable.
Yeah, the modern crop of fast, low pitch pressure gliders makes the one
point/shoulders only/pro tow option very attractive and it's nice not having to
reel in and stuff all that trailing bridle upon getting to altitude. I use and
feel reasonably comfortable with it myself when taking demo hops - especially
after getting the first hundred feet below me.
And the aerotow launch itself seems to have proved itself so insanely safe
that I was starting to think that maybe things weren't all that critical until
someone provided a lot of evidence to the contrary last summer.
The more difficult it is to effect a release the more people are gonna die.
Attention Eagle people:
If you're willing to invest in a couple of extra zipper pulls you don't have
to leave your sail unzipped.
The two point release I developed the better part of four years ago blows you
off tow with stored energy, is actuated with minimal force by sliding your
hand inboard along the basetube a couple of inches, and is lighter and
magnitudes cleaner than any other two point system out there. It restores virtually
all of the full point of performance that Rob Kells estimates the external cable
housing crap sucks out of your faired downtube and the transmission element
can't bind in such housing. It is also, as far as anyone has yet been able to
determine, one hundred percent reliable.
Yeah, the modern crop of fast, low pitch pressure gliders makes the one
point/shoulders only/pro tow option very attractive and it's nice not having to
reel in and stuff all that trailing bridle upon getting to altitude. I use and
feel reasonably comfortable with it myself when taking demo hops - especially
after getting the first hundred feet below me.
And the aerotow launch itself seems to have proved itself so insanely safe
that I was starting to think that maybe things weren't all that critical until
someone provided a lot of evidence to the contrary last summer.
The more difficult it is to effect a release the more people are gonna die.
Attention Eagle people:
If you're willing to invest in a couple of extra zipper pulls you don't have
to leave your sail unzipped.
AT releases
Thanks, Tad. I was too green to fully appreciate your system when you
showed it to me a couple of years ago. Now I'm more interested. Do I
have to fabricate this myself from parts or are you in business? - Hugh
On 5 Mar 2005, at 11:44, TadErcksn@aol.com wrote:
>
> Damn, Hugh stole a lot of my thunder before I could post but...
>
> The two point release I developed the better part of four years ago
> blows you
> off tow with stored energy, is actuated with minimal force by sliding
> your
> hand inboard along the basetube a couple of inches, and is lighter and
> magnitudes cleaner than any other two point system out there. It
> restores virtually
> all of the full point of performance that Rob Kells estimates the
> external cable
> housing crap sucks out of your faired downtube and the transmission
> element
> can't bind in such housing. It is also, as far as anyone has yet been
> able to
> determine, one hundred percent reliable.
>
> Yeah, the modern crop of fast, low pitch pressure gliders makes the one
> point/shoulders only/pro tow option very attractive and it's nice not
> having to
> reel in and stuff all that trailing bridle upon getting to altitude.
> I use and
> feel reasonably comfortable with it myself when taking demo hops -
> especially
> after getting the first hundred feet below me.
>
> And the aerotow launch itself seems to have proved itself so insanely
> safe
> that I was starting to think that maybe things weren't all that
> critical until
> someone provided a lot of evidence to the contrary last summer.
>
> The more difficult it is to effect a release the more people are gonna
> die.
>
> Attention Eagle people:
>
> If you're willing to invest in a couple of extra zipper pulls you
> don't have
> to leave your sail unzipped.
>
>
showed it to me a couple of years ago. Now I'm more interested. Do I
have to fabricate this myself from parts or are you in business? - Hugh
On 5 Mar 2005, at 11:44, TadErcksn@aol.com wrote:
>
> Damn, Hugh stole a lot of my thunder before I could post but...
>
> The two point release I developed the better part of four years ago
> blows you
> off tow with stored energy, is actuated with minimal force by sliding
> your
> hand inboard along the basetube a couple of inches, and is lighter and
> magnitudes cleaner than any other two point system out there. It
> restores virtually
> all of the full point of performance that Rob Kells estimates the
> external cable
> housing crap sucks out of your faired downtube and the transmission
> element
> can't bind in such housing. It is also, as far as anyone has yet been
> able to
> determine, one hundred percent reliable.
>
> Yeah, the modern crop of fast, low pitch pressure gliders makes the one
> point/shoulders only/pro tow option very attractive and it's nice not
> having to
> reel in and stuff all that trailing bridle upon getting to altitude.
> I use and
> feel reasonably comfortable with it myself when taking demo hops -
> especially
> after getting the first hundred feet below me.
>
> And the aerotow launch itself seems to have proved itself so insanely
> safe
> that I was starting to think that maybe things weren't all that
> critical until
> someone provided a lot of evidence to the contrary last summer.
>
> The more difficult it is to effect a release the more people are gonna
> die.
>
> Attention Eagle people:
>
> If you're willing to invest in a couple of extra zipper pulls you
> don't have
> to leave your sail unzipped.
>
>
-
- Posts: 304
- Joined: Wed Feb 09, 2005 8:50 am
AT releases
Oh joy of joys! Finally the prospect of doubling the population of this
system.
Yeah, I welcome with open arms anyone - individual, park, manufacturer - to
plagiarize this rig and keep all that R&D from going the way of Beta tape and,
yeah, I'd be happy to be in the business if anyone would rather avoid the
hassle him-/herself.
I've got extensive documentation on components, loads, and specs and have
written (and several times rewritten) an article. Kolie and Pauls Adamez and
Gerhardt have been very kind to do some photo shoots but I keep finding things I
should have set up better and really ought to go out with a tripod and
sacrifice part of a day before going to press.
Re the first Paul's concerns...
The spinnaker shackle doesn't fail in its function. If a reasonable pull is
applied to the spring loaded latch the gate opens. (Caveat - I have found
that a hang up of the weak link on the notch at the gate may occur upon a low
tension release but it doesn't last long after a little tension is restored.)
It's the activation and transmission elements that fail. Problems I've seen
and/or had reported include improper adjustment of cable play, insufficient throw
capability of the mounted brake lever assembly, and binding of cable and
housing (the sort of problem that used to render a lot of ballistic parachutes
inert). Although the loop activated flavor appears to be a pretty reasonable
second-best, Sunny related that Highland has seen so many failures that they no
longer sell them (your mileage may vary).
The leech line based transmission, evolutionary variations of which I've been
using since 1994, does not fail and is extremely efficient in delivering the
force to where it's needed.
Yeah, the scenario Paul described involving a two point system in which the
primary fails and the bridle wraps could be a real nightmare - especially if
the trim point is way forward on your keel (like mine). There was a group of
tow pilots who hadn't thought things through more than the initial step members
of which were deliberately releasing at the bottom end of the bridle so that
it would stream better out of the way during free flight. When step two
chanced along one of them had his glider fail under negative loading and was lucky
to just get majorly injured.
But in the course of conventional setups and operation this, statistically,
just isn't on the screen - especially if you're using proper equipment and
technique.
Bridle wraps are rare and almost nonexistent if:
the ends are cleanly spliced or tapered and it's of a fairly stiff,
inelastic, and substantial material;
weak links aren't stupidly long; and
releases are initiated under low tension.
The wisdom I scored from Sunny regarding the last point is... At wave off,
climb, dive to slacken the tow line, and release. The tow ring (carabiner)
slowly falls away while the bridle gently feeds through it. (Also eliminates
that annoying stall one experiences otherwise and the shackle doesn't hammer
itself.)
Further along - let's make this a worst case lockout scenario - there's a
weak link at the top of the bridle which will now be experiencing something along
the lines of a double load and a tug driver with a lever on that end which
may do you some good.
And, again, the technology has existed for over a decade such that no one
should even be worrying about a primary release failure.
And there's very little reason that we should have to let go of the steering
wheel to try grab something at a bad time either.
I also note in the 2005/02/21 installment of the Oz Report a reference to
failure of the secondary bridle to feed through the end of the primary after a
wrap. I've been using a painfully obvious remedy to that problem - which also
prevents those components of your equipment from sawing each other apart - for
over a decade as well. It involves a stainless steel sail thimble.
system.
Yeah, I welcome with open arms anyone - individual, park, manufacturer - to
plagiarize this rig and keep all that R&D from going the way of Beta tape and,
yeah, I'd be happy to be in the business if anyone would rather avoid the
hassle him-/herself.
I've got extensive documentation on components, loads, and specs and have
written (and several times rewritten) an article. Kolie and Pauls Adamez and
Gerhardt have been very kind to do some photo shoots but I keep finding things I
should have set up better and really ought to go out with a tripod and
sacrifice part of a day before going to press.
Re the first Paul's concerns...
The spinnaker shackle doesn't fail in its function. If a reasonable pull is
applied to the spring loaded latch the gate opens. (Caveat - I have found
that a hang up of the weak link on the notch at the gate may occur upon a low
tension release but it doesn't last long after a little tension is restored.)
It's the activation and transmission elements that fail. Problems I've seen
and/or had reported include improper adjustment of cable play, insufficient throw
capability of the mounted brake lever assembly, and binding of cable and
housing (the sort of problem that used to render a lot of ballistic parachutes
inert). Although the loop activated flavor appears to be a pretty reasonable
second-best, Sunny related that Highland has seen so many failures that they no
longer sell them (your mileage may vary).
The leech line based transmission, evolutionary variations of which I've been
using since 1994, does not fail and is extremely efficient in delivering the
force to where it's needed.
Yeah, the scenario Paul described involving a two point system in which the
primary fails and the bridle wraps could be a real nightmare - especially if
the trim point is way forward on your keel (like mine). There was a group of
tow pilots who hadn't thought things through more than the initial step members
of which were deliberately releasing at the bottom end of the bridle so that
it would stream better out of the way during free flight. When step two
chanced along one of them had his glider fail under negative loading and was lucky
to just get majorly injured.
But in the course of conventional setups and operation this, statistically,
just isn't on the screen - especially if you're using proper equipment and
technique.
Bridle wraps are rare and almost nonexistent if:
the ends are cleanly spliced or tapered and it's of a fairly stiff,
inelastic, and substantial material;
weak links aren't stupidly long; and
releases are initiated under low tension.
The wisdom I scored from Sunny regarding the last point is... At wave off,
climb, dive to slacken the tow line, and release. The tow ring (carabiner)
slowly falls away while the bridle gently feeds through it. (Also eliminates
that annoying stall one experiences otherwise and the shackle doesn't hammer
itself.)
Further along - let's make this a worst case lockout scenario - there's a
weak link at the top of the bridle which will now be experiencing something along
the lines of a double load and a tug driver with a lever on that end which
may do you some good.
And, again, the technology has existed for over a decade such that no one
should even be worrying about a primary release failure.
And there's very little reason that we should have to let go of the steering
wheel to try grab something at a bad time either.
I also note in the 2005/02/21 installment of the Oz Report a reference to
failure of the secondary bridle to feed through the end of the primary after a
wrap. I've been using a painfully obvious remedy to that problem - which also
prevents those components of your equipment from sawing each other apart - for
over a decade as well. It involves a stainless steel sail thimble.
AT releases
OK, Tad, you've blown me away with too much information - but the part
about loop-type releases having a higher failure rate sure got my
attention. What is the failure mode? Won't release or release
uncommanded? I've had the latter, just learned to make damn sure the
shackle is all the way on the gate. Let's get together at Ridgely or
in town and work on replicating your rig - or making a Mark II... -
Hugh
On 6 Mar 2005, at 14:33, TadErcksn@aol.com wrote:
>
> Oh joy of joys! Finally the prospect of doubling the population of
> this
> system.
>
> Yeah, I welcome with open arms anyone - individual, park, manufacturer
> - to
> plagiarize this rig and keep all that R&D from going the way of Beta
> tape and,
> yeah, I'd be happy to be in the business if anyone would rather avoid
> the
> hassle him-/herself.
>
> I've got extensive documentation on components, loads, and specs and
> have
> written (and several times rewritten) an article. Kolie and Pauls
> Adamez and
> Gerhardt have been very kind to do some photo shoots but I keep
> finding things I
> should have set up better and really ought to go out with a tripod and
> sacrifice part of a day before going to press.
>
> Re the first Paul's concerns...
>
> The spinnaker shackle doesn't fail in its function. If a reasonable
> pull is
> applied to the spring loaded latch the gate opens. (Caveat - I have
> found
> that a hang up of the weak link on the notch at the gate may occur
> upon a low
> tension release but it doesn't last long after a little tension is
> restored.)
> It's the activation and transmission elements that fail. Problems
> I've seen
> and/or had reported include improper adjustment of cable play,
> insufficient throw
> capability of the mounted brake lever assembly, and binding of cable
> and
> housing (the sort of problem that used to render a lot of ballistic
> parachutes
> inert). Although the loop activated flavor appears to be a pretty
> reasonable
> second-best, Sunny related that Highland has seen so many failures
> that they no
> longer sell them (your mileage may vary).
>
> The leech line based transmission, evolutionary variations of which
> I've been
> using since 1994, does not fail and is extremely efficient in
> delivering the
> force to where it's needed.
>
> Yeah, the scenario Paul described involving a two point system in
> which the
> primary fails and the bridle wraps could be a real nightmare -
> especially if
> the trim point is way forward on your keel (like mine). There was a
> group of
> tow pilots who hadn't thought things through more than the initial
> step members
> of which were deliberately releasing at the bottom end of the bridle
> so that
> it would stream better out of the way during free flight. When step
> two
> chanced along one of them had his glider fail under negative loading
> and was lucky
> to just get majorly injured.
>
> But in the course of conventional setups and operation this,
> statistically,
> just isn't on the screen - especially if you're using proper equipment
> and
> technique.
>
> Bridle wraps are rare and almost nonexistent if:
>
> the ends are cleanly spliced or tapered and it's of a fairly stiff,
> inelastic, and substantial material;
> weak links aren't stupidly long; and
> releases are initiated under low tension.
>
> The wisdom I scored from Sunny regarding the last point is... At wave
> off,
> climb, dive to slacken the tow line, and release. The tow ring
> (carabiner)
> slowly falls away while the bridle gently feeds through it. (Also
> eliminates
> that annoying stall one experiences otherwise and the shackle doesn't
> hammer
> itself.)
>
> Further along - let's make this a worst case lockout scenario -
> there's a
> weak link at the top of the bridle which will now be experiencing
> something along
> the lines of a double load and a tug driver with a lever on that end
> which
> may do you some good.
>
> And, again, the technology has existed for over a decade such that no
> one
> should even be worrying about a primary release failure.
>
> And there's very little reason that we should have to let go of the
> steering
> wheel to try grab something at a bad time either.
>
> I also note in the 2005/02/21 installment of the Oz Report a reference
> to
> failure of the secondary bridle to feed through the end of the primary
> after a
> wrap. I've been using a painfully obvious remedy to that problem -
> which also
> prevents those components of your equipment from sawing each other
> apart - for
> over a decade as well. It involves a stainless steel sail thimble.
>
>
about loop-type releases having a higher failure rate sure got my
attention. What is the failure mode? Won't release or release
uncommanded? I've had the latter, just learned to make damn sure the
shackle is all the way on the gate. Let's get together at Ridgely or
in town and work on replicating your rig - or making a Mark II... -
Hugh
On 6 Mar 2005, at 14:33, TadErcksn@aol.com wrote:
>
> Oh joy of joys! Finally the prospect of doubling the population of
> this
> system.
>
> Yeah, I welcome with open arms anyone - individual, park, manufacturer
> - to
> plagiarize this rig and keep all that R&D from going the way of Beta
> tape and,
> yeah, I'd be happy to be in the business if anyone would rather avoid
> the
> hassle him-/herself.
>
> I've got extensive documentation on components, loads, and specs and
> have
> written (and several times rewritten) an article. Kolie and Pauls
> Adamez and
> Gerhardt have been very kind to do some photo shoots but I keep
> finding things I
> should have set up better and really ought to go out with a tripod and
> sacrifice part of a day before going to press.
>
> Re the first Paul's concerns...
>
> The spinnaker shackle doesn't fail in its function. If a reasonable
> pull is
> applied to the spring loaded latch the gate opens. (Caveat - I have
> found
> that a hang up of the weak link on the notch at the gate may occur
> upon a low
> tension release but it doesn't last long after a little tension is
> restored.)
> It's the activation and transmission elements that fail. Problems
> I've seen
> and/or had reported include improper adjustment of cable play,
> insufficient throw
> capability of the mounted brake lever assembly, and binding of cable
> and
> housing (the sort of problem that used to render a lot of ballistic
> parachutes
> inert). Although the loop activated flavor appears to be a pretty
> reasonable
> second-best, Sunny related that Highland has seen so many failures
> that they no
> longer sell them (your mileage may vary).
>
> The leech line based transmission, evolutionary variations of which
> I've been
> using since 1994, does not fail and is extremely efficient in
> delivering the
> force to where it's needed.
>
> Yeah, the scenario Paul described involving a two point system in
> which the
> primary fails and the bridle wraps could be a real nightmare -
> especially if
> the trim point is way forward on your keel (like mine). There was a
> group of
> tow pilots who hadn't thought things through more than the initial
> step members
> of which were deliberately releasing at the bottom end of the bridle
> so that
> it would stream better out of the way during free flight. When step
> two
> chanced along one of them had his glider fail under negative loading
> and was lucky
> to just get majorly injured.
>
> But in the course of conventional setups and operation this,
> statistically,
> just isn't on the screen - especially if you're using proper equipment
> and
> technique.
>
> Bridle wraps are rare and almost nonexistent if:
>
> the ends are cleanly spliced or tapered and it's of a fairly stiff,
> inelastic, and substantial material;
> weak links aren't stupidly long; and
> releases are initiated under low tension.
>
> The wisdom I scored from Sunny regarding the last point is... At wave
> off,
> climb, dive to slacken the tow line, and release. The tow ring
> (carabiner)
> slowly falls away while the bridle gently feeds through it. (Also
> eliminates
> that annoying stall one experiences otherwise and the shackle doesn't
> hammer
> itself.)
>
> Further along - let's make this a worst case lockout scenario -
> there's a
> weak link at the top of the bridle which will now be experiencing
> something along
> the lines of a double load and a tug driver with a lever on that end
> which
> may do you some good.
>
> And, again, the technology has existed for over a decade such that no
> one
> should even be worrying about a primary release failure.
>
> And there's very little reason that we should have to let go of the
> steering
> wheel to try grab something at a bad time either.
>
> I also note in the 2005/02/21 installment of the Oz Report a reference
> to
> failure of the secondary bridle to feed through the end of the primary
> after a
> wrap. I've been using a painfully obvious remedy to that problem -
> which also
> prevents those components of your equipment from sawing each other
> apart - for
> over a decade as well. It involves a stainless steel sail thimble.
>
>
AT releases
I believe the problem is not with the method of pulling the release, but
the way the gate itself was configured with these models - the tow line
would end up pulling on the hinge and there was thus no force to pull the
gate open. There's a couple of ways to mitigate this problem by changing
the way the gate is suspended, but the problem is *not* with the loop pull
itself.
There's a line that connects the gate to the glider. If this line
attaches exactly opposite to the hinge, there's a good chance the tow line
will naturally pull against the hinge. If this is happening it's
imperative to reroute the attachment line.
I had problems with my pull loop release until I had the
attachment line rerouted. At some point Ralph flew my glider and was
scared silly when it didn't release, but unfortunately I don't remember if
this was before or after I rerouted the line.
There may have been other problems associated with not having
extra force from the lever effect of the bicycle release. Sunny or Adam
may know.
Brian Vant-Hull
301-646-1149
On Sun, 6 Mar 2005 mcelrah@verizon.net wrote:
>
> OK, Tad, you've blown me away with too much information - but the part
> about loop-type releases having a higher failure rate sure got my
> attention. What is the failure mode? Won't release or release
> uncommanded? I've had the latter, just learned to make damn sure the
> shackle is all the way on the gate. Let's get together at Ridgely or
> in town and work on replicating your rig - or making a Mark II... -
> Hugh
>
> On 6 Mar 2005, at 14:33, TadErcksn@aol.com wrote:
>
> >
> > Oh joy of joys! Finally the prospect of doubling the population of
> > this
> > system.
> >
> > Yeah, I welcome with open arms anyone - individual, park, manufacturer
> > - to
> > plagiarize this rig and keep all that R&D from going the way of Beta
> > tape and,
> > yeah, I'd be happy to be in the business if anyone would rather avoid
> > the
> > hassle him-/herself.
> >
> > I've got extensive documentation on components, loads, and specs and
> > have
> > written (and several times rewritten) an article. Kolie and Pauls
> > Adamez and
> > Gerhardt have been very kind to do some photo shoots but I keep
> > finding things I
> > should have set up better and really ought to go out with a tripod and
> > sacrifice part of a day before going to press.
> >
> > Re the first Paul's concerns...
> >
> > The spinnaker shackle doesn't fail in its function. If a reasonable
> > pull is
> > applied to the spring loaded latch the gate opens. (Caveat - I have
> > found
> > that a hang up of the weak link on the notch at the gate may occur
> > upon a low
> > tension release but it doesn't last long after a little tension is
> > restored.)
> > It's the activation and transmission elements that fail. Problems
> > I've seen
> > and/or had reported include improper adjustment of cable play,
> > insufficient throw
> > capability of the mounted brake lever assembly, and binding of cable
> > and
> > housing (the sort of problem that used to render a lot of ballistic
> > parachutes
> > inert). Although the loop activated flavor appears to be a pretty
> > reasonable
> > second-best, Sunny related that Highland has seen so many failures
> > that they no
> > longer sell them (your mileage may vary).
> >
> > The leech line based transmission, evolutionary variations of which
> > I've been
> > using since 1994, does not fail and is extremely efficient in
> > delivering the
> > force to where it's needed.
> >
> > Yeah, the scenario Paul described involving a two point system in
> > which the
> > primary fails and the bridle wraps could be a real nightmare -
> > especially if
> > the trim point is way forward on your keel (like mine). There was a
> > group of
> > tow pilots who hadn't thought things through more than the initial
> > step members
> > of which were deliberately releasing at the bottom end of the bridle
> > so that
> > it would stream better out of the way during free flight. When step
> > two
> > chanced along one of them had his glider fail under negative loading
> > and was lucky
> > to just get majorly injured.
> >
> > But in the course of conventional setups and operation this,
> > statistically,
> > just isn't on the screen - especially if you're using proper equipment
> > and
> > technique.
> >
> > Bridle wraps are rare and almost nonexistent if:
> >
> > the ends are cleanly spliced or tapered and it's of a fairly stiff,
> > inelastic, and substantial material;
> > weak links aren't stupidly long; and
> > releases are initiated under low tension.
> >
> > The wisdom I scored from Sunny regarding the last point is... At wave
> > off,
> > climb, dive to slacken the tow line, and release. The tow ring
> > (carabiner)
> > slowly falls away while the bridle gently feeds through it. (Also
> > eliminates
> > that annoying stall one experiences otherwise and the shackle doesn't
> > hammer
> > itself.)
> >
> > Further along - let's make this a worst case lockout scenario -
> > there's a
> > weak link at the top of the bridle which will now be experiencing
> > something along
> > the lines of a double load and a tug driver with a lever on that end
> > which
> > may do you some good.
> >
> > And, again, the technology has existed for over a decade such that no
> > one
> > should even be worrying about a primary release failure.
> >
> > And there's very little reason that we should have to let go of the
> > steering
> > wheel to try grab something at a bad time either.
> >
> > I also note in the 2005/02/21 installment of the Oz Report a reference
> > to
> > failure of the secondary bridle to feed through the end of the primary
> > after a
> > wrap. I've been using a painfully obvious remedy to that problem -
> > which also
> > prevents those components of your equipment from sawing each other
> > apart - for
> > over a decade as well. It involves a stainless steel sail thimble.
> >
> >
>
>
>
the way the gate itself was configured with these models - the tow line
would end up pulling on the hinge and there was thus no force to pull the
gate open. There's a couple of ways to mitigate this problem by changing
the way the gate is suspended, but the problem is *not* with the loop pull
itself.
There's a line that connects the gate to the glider. If this line
attaches exactly opposite to the hinge, there's a good chance the tow line
will naturally pull against the hinge. If this is happening it's
imperative to reroute the attachment line.
I had problems with my pull loop release until I had the
attachment line rerouted. At some point Ralph flew my glider and was
scared silly when it didn't release, but unfortunately I don't remember if
this was before or after I rerouted the line.
There may have been other problems associated with not having
extra force from the lever effect of the bicycle release. Sunny or Adam
may know.
Brian Vant-Hull
301-646-1149
On Sun, 6 Mar 2005 mcelrah@verizon.net wrote:
>
> OK, Tad, you've blown me away with too much information - but the part
> about loop-type releases having a higher failure rate sure got my
> attention. What is the failure mode? Won't release or release
> uncommanded? I've had the latter, just learned to make damn sure the
> shackle is all the way on the gate. Let's get together at Ridgely or
> in town and work on replicating your rig - or making a Mark II... -
> Hugh
>
> On 6 Mar 2005, at 14:33, TadErcksn@aol.com wrote:
>
> >
> > Oh joy of joys! Finally the prospect of doubling the population of
> > this
> > system.
> >
> > Yeah, I welcome with open arms anyone - individual, park, manufacturer
> > - to
> > plagiarize this rig and keep all that R&D from going the way of Beta
> > tape and,
> > yeah, I'd be happy to be in the business if anyone would rather avoid
> > the
> > hassle him-/herself.
> >
> > I've got extensive documentation on components, loads, and specs and
> > have
> > written (and several times rewritten) an article. Kolie and Pauls
> > Adamez and
> > Gerhardt have been very kind to do some photo shoots but I keep
> > finding things I
> > should have set up better and really ought to go out with a tripod and
> > sacrifice part of a day before going to press.
> >
> > Re the first Paul's concerns...
> >
> > The spinnaker shackle doesn't fail in its function. If a reasonable
> > pull is
> > applied to the spring loaded latch the gate opens. (Caveat - I have
> > found
> > that a hang up of the weak link on the notch at the gate may occur
> > upon a low
> > tension release but it doesn't last long after a little tension is
> > restored.)
> > It's the activation and transmission elements that fail. Problems
> > I've seen
> > and/or had reported include improper adjustment of cable play,
> > insufficient throw
> > capability of the mounted brake lever assembly, and binding of cable
> > and
> > housing (the sort of problem that used to render a lot of ballistic
> > parachutes
> > inert). Although the loop activated flavor appears to be a pretty
> > reasonable
> > second-best, Sunny related that Highland has seen so many failures
> > that they no
> > longer sell them (your mileage may vary).
> >
> > The leech line based transmission, evolutionary variations of which
> > I've been
> > using since 1994, does not fail and is extremely efficient in
> > delivering the
> > force to where it's needed.
> >
> > Yeah, the scenario Paul described involving a two point system in
> > which the
> > primary fails and the bridle wraps could be a real nightmare -
> > especially if
> > the trim point is way forward on your keel (like mine). There was a
> > group of
> > tow pilots who hadn't thought things through more than the initial
> > step members
> > of which were deliberately releasing at the bottom end of the bridle
> > so that
> > it would stream better out of the way during free flight. When step
> > two
> > chanced along one of them had his glider fail under negative loading
> > and was lucky
> > to just get majorly injured.
> >
> > But in the course of conventional setups and operation this,
> > statistically,
> > just isn't on the screen - especially if you're using proper equipment
> > and
> > technique.
> >
> > Bridle wraps are rare and almost nonexistent if:
> >
> > the ends are cleanly spliced or tapered and it's of a fairly stiff,
> > inelastic, and substantial material;
> > weak links aren't stupidly long; and
> > releases are initiated under low tension.
> >
> > The wisdom I scored from Sunny regarding the last point is... At wave
> > off,
> > climb, dive to slacken the tow line, and release. The tow ring
> > (carabiner)
> > slowly falls away while the bridle gently feeds through it. (Also
> > eliminates
> > that annoying stall one experiences otherwise and the shackle doesn't
> > hammer
> > itself.)
> >
> > Further along - let's make this a worst case lockout scenario -
> > there's a
> > weak link at the top of the bridle which will now be experiencing
> > something along
> > the lines of a double load and a tug driver with a lever on that end
> > which
> > may do you some good.
> >
> > And, again, the technology has existed for over a decade such that no
> > one
> > should even be worrying about a primary release failure.
> >
> > And there's very little reason that we should have to let go of the
> > steering
> > wheel to try grab something at a bad time either.
> >
> > I also note in the 2005/02/21 installment of the Oz Report a reference
> > to
> > failure of the secondary bridle to feed through the end of the primary
> > after a
> > wrap. I've been using a painfully obvious remedy to that problem -
> > which also
> > prevents those components of your equipment from sawing each other
> > apart - for
> > over a decade as well. It involves a stainless steel sail thimble.
> >
> >
>
>
>
-
- Posts: 304
- Joined: Wed Feb 09, 2005 8:50 am
AT releases
You really didn't expect me to shut up after a paragraph or two, did ya?
Release uncommanded is an annoyance, won't release is the potentially deadly
problem that puts the loop style on the Banned In Ridgely list. The complaint
I heard from Sunny was that the shackle wasn't opening. The problem that you
(Hugh) described in the former category is a byproduct of both styles and
another issue which disappears with a leech line setup.
With that detail on the checklist, I wouldn't sweat your copy - if it works,
it works. I kinda like it when stood alongside the bicycle brake jobs.
Checked one out as thoroughly as I could on the ground and the best I could
speculate was that the cable will, by definition, be subjected to two changes in
direction and the resulting binding resistance. Its counterpart often gets away
with one turn and, as Brian says, benefits from something on the order of a
four to one force magnification courtesy of the lever mechanical advantage.
I can, however, with a little effort imagine scenarios in which the loop
contributes to a control problem or broken wrist.
I've long been puzzled by reports of gates failing to open after the latch
has cleared (e.g. Ralph's 2000/08/26 malfunction (yes, prior to modification)).
The hypothesis is that our weak links, with their diameters magnitudes
smaller than the lines for which the Wichard Quick Release Shackle 2673 was
designed, focus their tension force directly on the center of the pivot point and
there isn't enough offset to start to swing the gate.
I've never been able to duplicate this failure on the ground (or in the air).
If I pull a loop of 130 pound braided Dacron directly in line it opens. If
I immobilize the shackle upside down (gate up), cram a loop of dental floss
inside the pivot cutout on both sides of the gate end, and pull the line aft 140
degrees and parallel to the fixed arm... it opens - easily and immediately.
A couple of seasons ago Les Taff informed me that the offset drilling
mutilation one often sees is not perpetrated to accommodate opening but to keep the
weak link from getting chewed up by the couple of sharp edges of the pivot
cutout. Apparently some copies are more problematic than others - I've never had
a problem with the ones I've used. And if I did I'd address the issue with a
file.
Another idea with respect to Paul's double failure scenario. In the event of
a primary malfunction under best case scenario options (i.e., at wave off) I
might give a thought to diving then pushing out and rolling (to minimize the
danger of the resulting stall) to try to pop the weak link before I started
using up other options. Opinions?
I don't have any great Mark II concepts. After release I'd like to rid
myself of about eight inches of taut leech line standing up against the breeze but
the last few years of thinking about it haven't yielded anything very
worthwhile.
I took a look at some U2 (right?) diagrams and the basetube looks like it
would be easy to work with.
Release uncommanded is an annoyance, won't release is the potentially deadly
problem that puts the loop style on the Banned In Ridgely list. The complaint
I heard from Sunny was that the shackle wasn't opening. The problem that you
(Hugh) described in the former category is a byproduct of both styles and
another issue which disappears with a leech line setup.
With that detail on the checklist, I wouldn't sweat your copy - if it works,
it works. I kinda like it when stood alongside the bicycle brake jobs.
Checked one out as thoroughly as I could on the ground and the best I could
speculate was that the cable will, by definition, be subjected to two changes in
direction and the resulting binding resistance. Its counterpart often gets away
with one turn and, as Brian says, benefits from something on the order of a
four to one force magnification courtesy of the lever mechanical advantage.
I can, however, with a little effort imagine scenarios in which the loop
contributes to a control problem or broken wrist.
I've long been puzzled by reports of gates failing to open after the latch
has cleared (e.g. Ralph's 2000/08/26 malfunction (yes, prior to modification)).
The hypothesis is that our weak links, with their diameters magnitudes
smaller than the lines for which the Wichard Quick Release Shackle 2673 was
designed, focus their tension force directly on the center of the pivot point and
there isn't enough offset to start to swing the gate.
I've never been able to duplicate this failure on the ground (or in the air).
If I pull a loop of 130 pound braided Dacron directly in line it opens. If
I immobilize the shackle upside down (gate up), cram a loop of dental floss
inside the pivot cutout on both sides of the gate end, and pull the line aft 140
degrees and parallel to the fixed arm... it opens - easily and immediately.
A couple of seasons ago Les Taff informed me that the offset drilling
mutilation one often sees is not perpetrated to accommodate opening but to keep the
weak link from getting chewed up by the couple of sharp edges of the pivot
cutout. Apparently some copies are more problematic than others - I've never had
a problem with the ones I've used. And if I did I'd address the issue with a
file.
Another idea with respect to Paul's double failure scenario. In the event of
a primary malfunction under best case scenario options (i.e., at wave off) I
might give a thought to diving then pushing out and rolling (to minimize the
danger of the resulting stall) to try to pop the weak link before I started
using up other options. Opinions?
I don't have any great Mark II concepts. After release I'd like to rid
myself of about eight inches of taut leech line standing up against the breeze but
the last few years of thinking about it haven't yielded anything very
worthwhile.
I took a look at some U2 (right?) diagrams and the basetube looks like it
would be easy to work with.
AT releases
I don't know where "banned from Ridgely" comes from, since several of us
have been using the pull loop system for years. After I rerouted the
attachment line I never had another release problem, and that was years
ago. I can understand they wouldn't sell them - though I think with
modification they are fine (preferable in my book for instant pull
access).
I rather like the "drilling mutilation" solution: the attachment line
rerouting is a little too subtle for my taste, but I don't have the tools
or perhaps even the skill to drill through a small section of curved metal
without the bit skating all over. Someday I'll probably have it done.
Brian Vant-Hull
301-646-1149
On Mon, 7 Mar 2005 TadErcksn@aol.com wrote:
>
> Release uncommanded is an annoyance, won't release is the potentially deadly
> problem that puts the loop style on the Banned In Ridgely list. The complaint
> I heard from Sunny was that the shackle wasn't opening. The problem that you
> (Hugh) described in the former category is a byproduct of both styles and
> another issue which disappears with a leech line setup.
>
have been using the pull loop system for years. After I rerouted the
attachment line I never had another release problem, and that was years
ago. I can understand they wouldn't sell them - though I think with
modification they are fine (preferable in my book for instant pull
access).
I rather like the "drilling mutilation" solution: the attachment line
rerouting is a little too subtle for my taste, but I don't have the tools
or perhaps even the skill to drill through a small section of curved metal
without the bit skating all over. Someday I'll probably have it done.
Brian Vant-Hull
301-646-1149
On Mon, 7 Mar 2005 TadErcksn@aol.com wrote:
>
> Release uncommanded is an annoyance, won't release is the potentially deadly
> problem that puts the loop style on the Banned In Ridgely list. The complaint
> I heard from Sunny was that the shackle wasn't opening. The problem that you
> (Hugh) described in the former category is a byproduct of both styles and
> another issue which disappears with a leech line setup.
>
-
- Posts: 304
- Joined: Wed Feb 09, 2005 8:50 am
AT releases
Naw, the "Banned In Ridgely" comment was just a reiteration of my earlier
mention that it's no longer available at the counter. And, yeah, it's next in my
preference line below what I've got and above the brake lever. If one is
accepting the aerodynamic penalties of a two point system anyway I think it's
nuts not to have the option of having a finger on the trigger when the cart
starts to roll. If the cable routing turn radii are sufficient and the bottom end
of the housing is properly secured I don't see a problem.
Although there doesn't seem to be any data to back up my paranoia I keep
envisioning the downstream end of the latter mechanism protruding from an eye
socket. Also seems like somebody is eventually gonna find a way to snag something
real important. And it doesn't exactly scream "streamlining".
I must part paths with you on my feelings about the drilling however - I
really, really hate it. Rotates the load 90 degrees from the way it was designed
to operate and dumps it all on the latch which wasn't envisioned to take
anything. And I'm wondering if it might have an adverse enough effect on required
trigger tension that you really need that brake lever mechanical advantage at
the upper range of things.
Before doing anything irreversible allow me to run a tensioner between the
fixed arm of the shackle and the glider's nose. If your attachment line
rerouting is addressing any problems, I believe the tensioner will do it better and
bestow a couple of other advantages as well.
Also, although, as I said, I've never had a problem, I just took a couple of
small files to a couple of spinnaker shackles and rounded out some sharp edges
around the pivot cutout and hinge pin riveted faces. It took a few minutes
and reduced the threat level to the weak link from no way to no freakin' way -
without marring the finish of those beautiful pieces of hardware. Possibly
more labor intensive than clamping one under a drill press but not much and with
infinitely more satisfactory results.
mention that it's no longer available at the counter. And, yeah, it's next in my
preference line below what I've got and above the brake lever. If one is
accepting the aerodynamic penalties of a two point system anyway I think it's
nuts not to have the option of having a finger on the trigger when the cart
starts to roll. If the cable routing turn radii are sufficient and the bottom end
of the housing is properly secured I don't see a problem.
Although there doesn't seem to be any data to back up my paranoia I keep
envisioning the downstream end of the latter mechanism protruding from an eye
socket. Also seems like somebody is eventually gonna find a way to snag something
real important. And it doesn't exactly scream "streamlining".
I must part paths with you on my feelings about the drilling however - I
really, really hate it. Rotates the load 90 degrees from the way it was designed
to operate and dumps it all on the latch which wasn't envisioned to take
anything. And I'm wondering if it might have an adverse enough effect on required
trigger tension that you really need that brake lever mechanical advantage at
the upper range of things.
Before doing anything irreversible allow me to run a tensioner between the
fixed arm of the shackle and the glider's nose. If your attachment line
rerouting is addressing any problems, I believe the tensioner will do it better and
bestow a couple of other advantages as well.
Also, although, as I said, I've never had a problem, I just took a couple of
small files to a couple of spinnaker shackles and rounded out some sharp edges
around the pivot cutout and hinge pin riveted faces. It took a few minutes
and reduced the threat level to the weak link from no way to no freakin' way -
without marring the finish of those beautiful pieces of hardware. Possibly
more labor intensive than clamping one under a drill press but not much and with
infinitely more satisfactory results.
AT releases
Duh... I've never thought of doing maneuvers before releasing - just
keep flying straight and level and pop the release. I don't normally
stall - just keep the nose at the same AOA (don't let it pop up) and
enjoy the relaxation of letting the glider fly at it's own speed
instead of being dragged faster than it wants to go. - Hugh
On 7 Mar 2005, at 09:15, TadErcksn@aol.com wrote:
>
> You really didn't expect me to shut up after a paragraph or two, did
> ya?
>
> Release uncommanded is an annoyance, won't release is the potentially
> deadly
> problem that puts the loop style on the Banned In Ridgely list. The
> complaint
> I heard from Sunny was that the shackle wasn't opening. The problem
> that you
> (Hugh) described in the former category is a byproduct of both styles
> and
> another issue which disappears with a leech line setup.
>
> With that detail on the checklist, I wouldn't sweat your copy - if it
> works,
> it works. I kinda like it when stood alongside the bicycle brake jobs.
> Checked one out as thoroughly as I could on the ground and the best I
> could
> speculate was that the cable will, by definition, be subjected to two
> changes in
> direction and the resulting binding resistance. Its counterpart often
> gets away
> with one turn and, as Brian says, benefits from something on the order
> of a
> four to one force magnification courtesy of the lever mechanical
> advantage.
>
> I can, however, with a little effort imagine scenarios in which the
> loop
> contributes to a control problem or broken wrist.
>
> I've long been puzzled by reports of gates failing to open after the
> latch
> has cleared (e.g. Ralph's 2000/08/26 malfunction (yes, prior to
> modification)).
> The hypothesis is that our weak links, with their diameters magnitudes
> smaller than the lines for which the Wichard Quick Release Shackle
> 2673 was
> designed, focus their tension force directly on the center of the
> pivot point and
> there isn't enough offset to start to swing the gate.
>
> I've never been able to duplicate this failure on the ground (or in
> the air).
> If I pull a loop of 130 pound braided Dacron directly in line it
> opens. If
> I immobilize the shackle upside down (gate up), cram a loop of dental
> floss
> inside the pivot cutout on both sides of the gate end, and pull the
> line aft 140
> degrees and parallel to the fixed arm... it opens - easily and
> immediately.
>
> A couple of seasons ago Les Taff informed me that the offset drilling
> mutilation one often sees is not perpetrated to accommodate opening
> but to keep the
> weak link from getting chewed up by the couple of sharp edges of the
> pivot
> cutout. Apparently some copies are more problematic than others -
> I've never had
> a problem with the ones I've used. And if I did I'd address the issue
> with a
> file.
>
> Another idea with respect to Paul's double failure scenario. In the
> event of
> a primary malfunction under best case scenario options (i.e., at wave
> off) I
> might give a thought to diving then pushing out and rolling (to
> minimize the
> danger of the resulting stall) to try to pop the weak link before I
> started
> using up other options. Opinions?
>
> I don't have any great Mark II concepts. After release I'd like to rid
> myself of about eight inches of taut leech line standing up against
> the breeze but
> the last few years of thinking about it haven't yielded anything very
> worthwhile.
>
> I took a look at some U2 (right?) diagrams and the basetube looks like
> it
> would be easy to work with.
>
>
keep flying straight and level and pop the release. I don't normally
stall - just keep the nose at the same AOA (don't let it pop up) and
enjoy the relaxation of letting the glider fly at it's own speed
instead of being dragged faster than it wants to go. - Hugh
On 7 Mar 2005, at 09:15, TadErcksn@aol.com wrote:
>
> You really didn't expect me to shut up after a paragraph or two, did
> ya?
>
> Release uncommanded is an annoyance, won't release is the potentially
> deadly
> problem that puts the loop style on the Banned In Ridgely list. The
> complaint
> I heard from Sunny was that the shackle wasn't opening. The problem
> that you
> (Hugh) described in the former category is a byproduct of both styles
> and
> another issue which disappears with a leech line setup.
>
> With that detail on the checklist, I wouldn't sweat your copy - if it
> works,
> it works. I kinda like it when stood alongside the bicycle brake jobs.
> Checked one out as thoroughly as I could on the ground and the best I
> could
> speculate was that the cable will, by definition, be subjected to two
> changes in
> direction and the resulting binding resistance. Its counterpart often
> gets away
> with one turn and, as Brian says, benefits from something on the order
> of a
> four to one force magnification courtesy of the lever mechanical
> advantage.
>
> I can, however, with a little effort imagine scenarios in which the
> loop
> contributes to a control problem or broken wrist.
>
> I've long been puzzled by reports of gates failing to open after the
> latch
> has cleared (e.g. Ralph's 2000/08/26 malfunction (yes, prior to
> modification)).
> The hypothesis is that our weak links, with their diameters magnitudes
> smaller than the lines for which the Wichard Quick Release Shackle
> 2673 was
> designed, focus their tension force directly on the center of the
> pivot point and
> there isn't enough offset to start to swing the gate.
>
> I've never been able to duplicate this failure on the ground (or in
> the air).
> If I pull a loop of 130 pound braided Dacron directly in line it
> opens. If
> I immobilize the shackle upside down (gate up), cram a loop of dental
> floss
> inside the pivot cutout on both sides of the gate end, and pull the
> line aft 140
> degrees and parallel to the fixed arm... it opens - easily and
> immediately.
>
> A couple of seasons ago Les Taff informed me that the offset drilling
> mutilation one often sees is not perpetrated to accommodate opening
> but to keep the
> weak link from getting chewed up by the couple of sharp edges of the
> pivot
> cutout. Apparently some copies are more problematic than others -
> I've never had
> a problem with the ones I've used. And if I did I'd address the issue
> with a
> file.
>
> Another idea with respect to Paul's double failure scenario. In the
> event of
> a primary malfunction under best case scenario options (i.e., at wave
> off) I
> might give a thought to diving then pushing out and rolling (to
> minimize the
> danger of the resulting stall) to try to pop the weak link before I
> started
> using up other options. Opinions?
>
> I don't have any great Mark II concepts. After release I'd like to rid
> myself of about eight inches of taut leech line standing up against
> the breeze but
> the last few years of thinking about it haven't yielded anything very
> worthwhile.
>
> I took a look at some U2 (right?) diagrams and the basetube looks like
> it
> would be easy to work with.
>
>
-
- Posts: 304
- Joined: Wed Feb 09, 2005 8:50 am
AT releases
I would strongly recommend the climb, dive, release procedure at all waves
off.
There's nothing that pops the nose up at release - it's been popped since you
left the cart. That may not be real apparent on the glider you're driving
but take a side view of a tug with glider in tow next time you're sinking past
such a combination.
If you release under tension the AOA changes instantly - and your pitch
attitude has to be reduced to regain it. Either you pull in or do nothing and wait
for the glider to work on the problem.
"Popping the release" subjects the spinnaker shackle to a bit of abuse and
the bridle to a little extra friction and wear but also sends the bridle, which
is supposed to keep going up with you, whipping towards equipment which is
about to descend with somebody else.
Give the gentle option a try - it's pretty neat watching the slow feed
through the floating carabiner. And I would be amazed if a wrap ever developed when
the tow line is slackened.
off.
There's nothing that pops the nose up at release - it's been popped since you
left the cart. That may not be real apparent on the glider you're driving
but take a side view of a tug with glider in tow next time you're sinking past
such a combination.
If you release under tension the AOA changes instantly - and your pitch
attitude has to be reduced to regain it. Either you pull in or do nothing and wait
for the glider to work on the problem.
"Popping the release" subjects the spinnaker shackle to a bit of abuse and
the bridle to a little extra friction and wear but also sends the bridle, which
is supposed to keep going up with you, whipping towards equipment which is
about to descend with somebody else.
Give the gentle option a try - it's pretty neat watching the slow feed
through the floating carabiner. And I would be amazed if a wrap ever developed when
the tow line is slackened.
AT releases
Winter boredom and the Oz report resulted in my invention of "the squid"AT shoulder release. This is a two ring (or 3 -- haven't decided which is better) where the final loop runs thru a grommet and you hold it in your teeth. Want off? Open your mouth. When you are 100 ft up and presumably out of danger you slide a barrel (the body of the squid) over the loop which crimps it at the grommet and you have a standard barrel release. I can hold on with my teeth all the way and not use the slider/keeper but gotta be sure I have fresh polident.
Tried it at Manquin and down in Fla. Seems to work fine. (flew with a standard barrel on the other side just in case) Also gets a lot of laughs. Show it to you.
Tried it at Manquin and down in Fla. Seems to work fine. (flew with a standard barrel on the other side just in case) Also gets a lot of laughs. Show it to you.