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Date: Tue, 13 May 2014 07:47:33 -0400
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From: "Dennis Johnson" <pinetownd@volcano.net>
References: <list-6869348@logan.com>
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Subject: Re: Legacy White Paper
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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