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"I believe that when the
canopy was suck up far enough that it blanketed the tail causing the aircraft to
pitch nose down, causing the closing of the canopy there in turn causing the
elevator to become effective again which then allowed me to regain control and
level again, which caused the canopy again to open, etc.,
etc."
This may or may not be relevant to open canopy
controllability, but I think the preceding description is backwards.
The tail provides negative lift in level flight, pushing the nose down, not
up. If the open canopy blanketed the tail, I think the nose would have
pitched up, not down.
I point this out for two reasons:
1. It's an important concept that all of
us pilots sometimes get backwards and that can lead us to make incorrect
decisions with possibly bad outcomes.
2. A Legacy pilot I respect took off with his canopy
open and reported that there was absolutely no control issues. Lots of
noise and charts blowing around, but the canopy opened a couple of inches
and stayed there. I'm unable to reconcile his report with the "Accident
Narrative" description.
I'm not saying that the error in the description of the
recent incident invalidates the conclusion that an open Legacy canopy
causes serious control issues. I can understand that in the heat of
battle, it would be easy to confuse whether the nose was pitching
up when the canopy opened or vice versa. But considering that I
have totally contradictory evidence from another Legacy open canopy
takeoff, it does create a question that should be answered.
Based on the numerous LML posts and discussions with other
Lancair pilots, taking off with an unlatched canopy is not uncommon and Legacy
pilots need to decide if it's a controllability issue or
not.
My personal opinion is that a warning light or buzzer that
the canopy is unlatched would be helpful, but insufficient. Pilots ignore
warning lights and buzzers all the time because we become totally focused on
other tasks. That is a well established fact. Or a passenger
could snag a sleeve or purse handle around the Legacy's canopy
latch handle and accidentally raise the handle in flight. If I really
believe that an open Legacy canopy has the potential to make the airplane
uncontrollable, the current latch handle, at a minimum, must be locked in
flight to prevent accidental opening.
Maybe it's just wishful thinking on my part, but for the
moment, I'm going with my friend's experience that there is no controllability
problem instead of the recent "Accident Narrative."
However, it has shaken that belief and I need to
reconsider.
I invite Lancair International to provide solid facts
on the issue, based on flight testing or aerodynamic modeling. If it
really is a controllability issue, we must do something to reduce the risk and
we must do it now. If it's not an issue, let's stop wasting time worrying
about warning lights and develop a training program to deal with an open
canopy.
Best,
Dennis
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