Mailing List lml@lancaironline.net Message #26664
From: Adam Molny <Adam@ValidationPartners.com>
Sender: Marvin Kaye <marv@lancaironline.net>
Subject: A few thoughts on rear-opening canopies
Date: Sat, 20 Nov 2004 21:31:37 -0500
To: <lml@lancaironline.net>
The intent of rear opening canopies is to improve safety by allowing
aircraft egress during an emergency. I propose that the cure may be
worse than the disease. We have all experienced a popped door or
unlatched canopy at one time or another. We are trained to handle this
as a non-event. We know that there is negligible impact on aircraft
performance, and the biggest challenge is keeping your cool when exposed
to the sudden increase in noise.

If a rear opening canopy pops open unintentionally in flight, you have a
major emergency. It will be torn away in an instant. Is an otherwise
undamaged Legacy flyable under those conditions? Could a pilot maintain
control while being hit in the face with a 300mph prop blast? Would he
be able to land the plane safely (assuming the canopy didn't take out
part of the empennage)? Yes, the rear opening canopy will do its job
when called upon, but it may actually decrease safety in day-to-day
operations.

The other issue is convenience in normal operations. I imagine that the
race-style canopy MUST be down-and-locked before engine start, and
remain latched until engine shutdown. You can't follow the usual
practice of leaving the canopy open a few inches to get some cool air
during ground operations. That could get old pretty quickly when you are
20th in line for takeoff on a 100deg day in Phoenix. This last issue is
probably an acceptable tradeoff for people flying purpose-built race
planes, where convenience is low on the priority list.

Just my thoughts on the issue,
Adam Molny
Legacy #151
Forward-hinging canopy
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