Message-ID: <004801c1769d$c503fb00$82cca443@roylok1.mi.home.com>
From: "Edmond de Chazal" <edechazal@home.com>
To: <lancair.list@olsusa.com>
References: <20011126051623.AAA13108@pop3.olsusa.com>
Subject: Re: Canopy Jettison
Date: Mon, 26 Nov 2001 12:14:12 -0500
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You folks thinking about a jettison feature for your canopy want to think it
through.  You need to be able to disengage the latching and hinging system
and then you need the canopy to depart the airframe in such a way that it
doesn't hit you in the process.  A quick look at the air pressure on the
canopy shows large downward pressure in the front (this pressure also
pushing towards the rear) and lifting pressure from the center rearward.  So
if the canopy were suddenly released, you can expect it to lift at the back
while the front edge moves rearward along the longerons very quickly.  You
better make sure it can't decapitate you or hit you so hard that you're
incapacitated.  Another possibility is that the canopy is pushed backwards
against the rollover so hard that it doesn't lift at the rear and simply
stays put.  Then you've got that additional linkages and possibility of
goofs in your custom design.  As far as getting out of the airplane, there's
a good chance of getting smacked by the tail it seems to me, all assuming
you can get yourself out of that tight sitting position we all have.  Of
course, it might all work as you hope.  On the other hand, why not simply
invest in some spin and unusual attitude recovery training which will make
you a safer pilot all the time?

Regards,
Ed de Chazal

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