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Dennis,
You first wrote about this "holder opener" 4 years and 400 hours ago.
I suppose that since then, the bracket has made a mark on the roll bar where
it probably moves as you taxi? Have you needed to do any repairs or
preventive maintenance at that area? Is there room for a piece of rubber or
something to protect this area around the bolt where the aluminum rests on
the fiberglass?
How difficult is it to latch the bracket and/or hook the bungee? Do you
have to look or can you do it by "feel" with one hand?
The aluminum bracket looks pretty lightweight. Has it shown any tendency to
bend or deform due to the canopy weight moving during taxi?
You say it will disengage if you raise the canopy slightly. Does this
happen with a strong wind from the rear? How well does it hold if the
bungee is engaged? How much force would be required to raise it if the
bungee was engaged?
I suppose the bracket hangs down by your right shoulder during flight. Is
it ever in your way with anything you do in the cockpit during flight?
If you had the bracket engaged and the bungee hooked, do you think the
canopy would stay in this position if you attempted or made a takeoff? No,
I am not suggesting you try it, I am just asking your opinion!
Do you have a better picture of the bolt that the bracket engages and the
hole/slot in the bracket? Does the head of the bolt contact anything on the
canopy when the canopy is closed and locked?
Is anyone else using this system or a modified version?
If you had to rebuild/replace this "holder opener" system with a better one,
what would you change?
Bill
-----Original Message-----
From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of
Dennis Johnson
Sent: Tuesday, May 13, 2014 6:48 AM
To: Lancair Mailing List
Subject: [LML] Re: Legacy White Paper
I'm a skeptic by nature and don't believe anything important without
convincing evidence. Withholding judgment until I'm convinced by the
evidence is a way of life for me and I take pride in saying, "I don't know"
when evidence is absent or unclear. For me, the root cause of Legacy open
canopy control issues falls within the category of insufficient to make a
conclusion.
I thank Valin for all his efforts and for making this a major topic of
conversation and thought. My personal feelings are that the white paper
offers many good (but unproven) hypotheses and I'm willing to overlook
opinions offered as facts in the interest of the greater good.
That's because the issue itself is literally life and death. It doesn't
matter if the Legacy with an unlatched canopy is inherently uncontrollable
in certain circumstances or not. The result is that people have died.
Regardless of the root cause, taking off with an unlatched canopy might be
fatal.
But there is a simple and inexpensive fix, in my opinion. I installed
Valin's clever canopy latch mod, which holds the canopy open a fraction of
an inch when either canopy latch handle is in the open position. I tested
it and running up the engine on the ground causes enough noise and canopy
shaking that even I would have a hard time ignoring it. My opinion is that
this simple modification could reduce the chance of taking off with an
unlatched canopy. Plus, it serves the original purpose, which is to lift
the canopy a fraction of an inch when the external latch handle is rotated
in order to make it easy to get a finger under the lip of the canopy to open
it.
I invite others to test it themselves. Everyone with Valin's canopy latch
modification, please do an engine run-up with the canopy closed but with the
canopy handle in the open position, which holds the canopy open a fraction
of an inch. Then report on the LML your results. Was there enough unusual
noise and vibration to make it unlikely you would take off that way?
One difference is that my canopy seal does not inflate until the canopy
handle is in the latched position. If you can inflate your canopy seal with
the latch open, try the run-up with the seal inflated and report the
results. Of course, make sure the canopy is fully closed and latched before
taking off!
I also installed a "canopy holder opener" that keeps the canopy open a few
inches for ventilation on the ground. As a result of Valin's paper, I have
now changed my procedure: My goal is that when on the ground, my canopy is
either fully open, fully closed and latched, or held open a few inches by
the "holder opener." My tests show that running up the engine with the
canopy held open a few inches is far too noisy and attention getting to
ignore.
Here is a link to photos and discussion of my canopy holder opener:
Mailing List lml@lancaironline.net Archived Message #54767
I'm not a big fan of a canopy open warning light because of unintended
consequences and, it seems to me, there is an effective and inexpensive
modification that might be more effective.
Thanks Valin, for helping me be a safer Legacy pilot!
Dennis
Legacy, 700 hours
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