If you are going to do something like this, I suggest that you incorporate the microswitch on the canopy with the throttle position so that a horn or buzzer goes off if the throttle is advanced beyond taxi position with the canopy not down and latched.  A light could be missed on take off until too late, but a horn would not.

 

Oh, if you design something like this, let me know how you did it!  :>)

 

Bill B

 

 

Hey Legacy pilots and builders,

 

There have now been two Legacy crashes, including the loss of a fellow pilot, apparently from canopy openings on takeoff.  I’m sure we’d all recognized even before these losses that the standard Legacy canopy latching system can easily mislead a pilot that it is closed but not be latched down.  And, with these great visibility bubble canopies, but hot green house effects, the canopies are usually propped open on the ground and not closed and latched until just before takeoff.  This makes it fairly likely that every Legacy pilot at some time, with fatigue or distractions, may not latch the canopy down before takeoff…

 

Given this probability of occurrence, we’ve been planning to use simple micro or proximity switches on both the canopy and the latch mechanism to control an indicator/light on our instrument panel as a secondary and hard to miss canopy configuration indicator.  It would be red whenever the canopy is not down OR not latched.  I haven’t yet decided if it would be good to have it green when the canopy is down and latched. 

 

Anyway, I just wanted to share this with other pilots and builders that are thinking about how to mitigate this in flight canopy opening risk after the second accident from this (apparent) root cause.  This kind of set up should be a very easy retrofit for flying Legacy airplanes, too.

 

 

Valin Thorn

Legacy

Houston, TX USA

http://www.starflight.aero/legacy/

 

 

P.S.  Also, if you do the mod we worked up a few years ago that props the canopy open when you unlatch the canopy (so you can get your fingers under it to open it) you get another more clear indication that the canopy is not latched…  Don Barnes has this info on his website:

 

http://www.lancairlegacy.com/tips_canopy_fixes.html