FLARM antenna mounts for ASG-29

Oh? Have any of them attempted to jettison their canopies in flight and had
it remain attached by that coax cable and/or mount?

I only expressed doubts due to the forces expected by the huge drag of the
jettisoned canopy. I can't control what "some of the top pilots in the
world" think or do. It's up to them to decide for themselves. I stand by
my doubt.

BTW, there is absolutely NOTHING connected to my canopy. It will float
freely away should I pull the handle.


"Craig R." wrote in message
...
Dan, some of the top pilots in the world flying 29's will disagree with
you and have taken precautions for their antenna installation.


On Thursday, September 5, 2013 7:02:51 AM UTC-7, Dan Marotta wrote:
It's doubtful those flimsy cables/mounts would retain a canopy against the
relative wind.

There was a fatality few years ago in Europe where the pilot did not successfully bail out after a midair where the PDA wires connected to the canopy where suspected as contributing factor.

Ramy

Currently my flarm antenna is mounted to where the cable would indeed
interfere in case of canopy jettison.

Fixing this is at the very top of my to do list for sure, I believe if you
grabbed that antenna wire with your bare hands and pulled it may take more force to break than what you may think.

Suspected...? Show me the pictures and/or official report. Was the canopy
still tied to the wreck as found on the ground? I just don't believe it
unless the cables used were much heavier than the normal PDA cables and were
retained via adel clamps or some such. In all likelihood, connectors would
simply separate or the wires would pull out of the connectors, or the cables
would simply break.

Accident reports, it seems, often blame some unproveable happening and, if
the pilot doesn't survive, he usually gets more than his fair share of the
blame. My objection here is simply to the blind belief that something bad
will happen if you don't do what the "top pilots in the world" do.

Did you note in my previous reply that there is NOTHING connecting my canopy
to the fuselage other than the retention hook? That's not because I'm
afraid of bad things, it's simply for convenience.

I helped a local pilot with her FLARM installation on her new -29 and she
had the antennae mounted to the glare shield. To me the mounts looked
flimsy and would easily separate should the canopy be jettisoned in flight.
The down side was the extra long cable lengths needed to remove the canopy
and set it on the ground so that she could disconnect the cables. Same for
reinstallation of the canopy.

In writing this it occurs to me that those long cables would allow the
difference in velocity of the canopy and airframe to increase sufficiently
to easily snap the cables or mounts.


"Ramy" wrote in message
...
There was a fatality few years ago in Europe where the pilot did not
successfully bail out after a midair where the PDA wires connected to the
canopy where suspected as contributing factor.

Ramy

A Google search away. http://www.aaib.gov.uk/publications/...lider__gdp.cfm

The onus is really not on people to prove doing things are unsafe, the onus is really more on doing things that might be unsafe and proving they are indeed, contrary to obvious concerns, safe.

Like many other owners/pilots I observed, I have installed systems in multiple gliders that have cable connector breakaways (e.g. with telco connectors with the retaining tab mostly removed) and tested as best I can on the ground to make sure the separation works with very little force. etc. to allow easy canopy jettison. I also woudl not want long pieces of cable coming back at the pilot, maybe flailing around in the wind etc. while the pilot is tryign to undo their harness and deal with everything else going on. If you have installed cables fixed to a canopy and think the cable will break and allow straightforward canopy jettison maybe you could share your calculations/design and any testing you did here.

For the third and final time, there is NOTHING attached to my canopy. And
my opinion is just that - my opinion.


"Darryl Ramm" wrote in message
...
A Google search away.
http://www.aaib.gov.uk/publications/...lider__gdp.cfm

The onus is really not on people to prove doing things are unsafe, the onus
is really more on doing things that might be unsafe and proving they are
indeed, contrary to obvious concerns, safe.

Like many other owners/pilots I observed, I have installed systems in
multiple gliders that have cable connector breakaways (e.g. with telco
connectors with the retaining tab mostly removed) and tested as best I can
on the ground to make sure the separation works with very little force. etc.
to allow easy canopy jettison. I also woudl not want long pieces of cable
coming back at the pilot, maybe flailing around in the wind etc. while the
pilot is tryign to undo their harness and deal with everything else going
on. If you have installed cables fixed to a canopy and think the cable will
break and allow straightforward canopy jettison maybe you could share your
calculations/design and any testing you did here.

OK, I read the accident report and I can't agree with their findings. The
following was lifted directly from the report:

"A section of canopy of the ASW 19B was found at the top of Sutton Bank, and
the rest of the canopy was found in close proximity to the glider's
fuselage, some 500 m away. Examination of the glider confirmed that the
jettison procedure had been initiated, but not completed, before
impact with the ground. The forward section of the canopy frame had been
released from the 'lifting arm' prior to ground impact, but the canopy
locking pins were in the 'LOCkeD' position."

Part of the canopy was found quite a ways off (it seems) and the rest was
found some 500m from the wreck. I doubt it would have bounced that far
following the crash. The report mentions the cables apparently being quite
securely fastened to the canopy frame so I've just gotta ask, "How long were
those cables?" 500m? Or did they break loose?

Please understand that I'm not promoting connecting anything to a
jettisonable part of the aircraft. I'm just saying that, if you do, it
likely won't kill you.

And BTW, I used to own an ASW-19b and, if I recall correctly, there was no
spring action to positively jettison the canopy and there was the definite
risk of getting hit in the head by the thing when it did decide to leave.

"Dan Marotta" wrote in message
...
For the third and final time, there is NOTHING attached to my canopy. And
my opinion is just that - my opinion.


"Darryl Ramm" wrote in message
...
A Google search away.
http://www.aaib.gov.uk/publications/...lider__gdp.cfm

The onus is really not on people to prove doing things are unsafe, the
onus is really more on doing things that might be unsafe and proving they
are indeed, contrary to obvious concerns, safe.

Like many other owners/pilots I observed, I have installed systems in
multiple gliders that have cable connector breakaways (e.g. with telco
connectors with the retaining tab mostly removed) and tested as best I can
on the ground to make sure the separation works with very little force.
etc. to allow easy canopy jettison. I also woudl not want long pieces of
cable coming back at the pilot, maybe flailing around in the wind etc.
while the pilot is tryign to undo their harness and deal with everything
else going on. If you have installed cables fixed to a canopy and think
the cable will break and allow straightforward canopy jettison maybe you
could share your calculations/design and any testing you did here.

On Fri, 06 Sep 2013 19:15:13 -0600, Dan Marotta wrote:

OK, I read the accident report and I can't agree with their findings.
The following was lifted directly from the report:

"A section of canopy of the ASW 19B was found at the top of Sutton Bank,
and the rest of the canopy was found in close proximity to the glider's
fuselage, some 500 m away. Examination of the glider confirmed that the
jettison procedure had been initiated, but not completed, before impact
with the ground. The forward section of the canopy frame had been
released from the 'lifting arm' prior to ground impact, but the canopy
locking pins were in the 'LOCkeD' position."

Part of the canopy was found quite a ways off (it seems) and the rest
was found some 500m from the wreck. I doubt it would have bounced that
far following the crash. The report mentions the cables apparently
being quite securely fastened to the canopy frame so I've just gotta
ask, "How long were those cables?" 500m? Or did they break loose?

With respect, I think you misread that. I read it as saying that part of
the canopy was at the top of Sutton Bank. The rest of the canopy *and the
fuselage* were close together and about 500m from the detached portion.


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

If I did misread it, then I stand corrected. Even though we speak the same
language across the pond, it's not always received the same way.


"Martin Gregorie" wrote in message
...
On Fri, 06 Sep 2013 19:15:13 -0600, Dan Marotta wrote:

OK, I read the accident report and I can't agree with their findings.
The following was lifted directly from the report:

"A section of canopy of the ASW 19B was found at the top of Sutton Bank,
and the rest of the canopy was found in close proximity to the glider's
fuselage, some 500 m away. Examination of the glider confirmed that the
jettison procedure had been initiated, but not completed, before impact
with the ground. The forward section of the canopy frame had been
released from the 'lifting arm' prior to ground impact, but the canopy
locking pins were in the 'LOCkeD' position."

Part of the canopy was found quite a ways off (it seems) and the rest
was found some 500m from the wreck. I doubt it would have bounced that
far following the crash. The report mentions the cables apparently
being quite securely fastened to the canopy frame so I've just gotta
ask, "How long were those cables?" 500m? Or did they break loose?

With respect, I think you misread that. I read it as saying that part of
the canopy was at the top of Sutton Bank. The rest of the canopy *and the
fuselage* were close together and about 500m from the detached portion.


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

On Sat, 07 Sep 2013 09:47:39 -0600, Dan Marotta wrote:

If I did misread it, then I stand corrected. Even though we speak the
same language across the pond, it's not always received the same way.

The wording could have been improved.

I'd have written it as:
"A section of canopy of the ASW 19B was found at the top of Sutton Bank,
and the rest of the canopy was found in 500m away in close proximity to
the glider's fuselage. Examination of the glider confirmed that the
jettison procedure had been initiated, but not completed, before impact
with the ground. The forward section of the canopy frame had been
released from the 'lifting arm' prior to ground impact, but the canopy
locking pins were in the 'LOCkeD' position."

I remember reading the AAIB report when it came out.

I presume that by 'the locking pins' they mean the two pins at the rear
that hold the canopy closed. With the front of the canopy freed from the
lifting arm that normally acts as the front pivot but restrained by the
PDA cables after the front had lifted a foot or two, those two pins and
the cable would certainly keep the canopy attached and prevent egress.


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