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