Canopy Jettison??

idleup · #1 02-25-2007, 12:08 AM

Is the general concensus to not install the canopy Jettison components on the tip up? I have not seen many panels with a jettison handle in the middle of them. Does that mean most people are not installing it and just using bolts instead of the pins?

jsharkey · #2 02-25-2007, 05:05 AM

I installed the mechanism in my -6. I think it will be good for quick release maintenance but the canopy uses gas lift struts and the newer "J" type hinges that hook under upper skin. I have my doubts as to whether the thing will actually release and fly off if I ever did pull the handle in flight. Does anyone have real life experience?
Jim Sharkey

terrykohler · #3 02-25-2007, 05:09 AM

Matt:
You should plan to install the bellcrank mechanism and run the actuator rod vertically down the sub-panel. At some point, you'll want to be able to remove the canopy and this arrangement allows you to do so without taking up valuable real estate on the IP. Wish I had taken this approach when I built my 9A. Don't believe anyone has actually jettisoned the canopy in flight.
Terry

robertahegy · #4 02-25-2007, 05:46 AM

I put the mechanism in for easy canopy removal. I also turned the handle horizontal so it does not get in the way so much. It really makes getting the canopy off a breeze. I never intended it to be jettisoned. They tell you to place thin material over the hinges so it tears away in a jettison mode and if you are doing aerobatics where you may need to jettison, to take the gas struts off.

Roberta

db1yg · #5 02-25-2007, 05:52 AM

Matt,

I have seen the jettison system installed as per plans, installed with the release handle pointed down at the sub panel, the release handle pointed forward and accessable under the cowl at the firewall, and not installed at all. With the j hinge (I believe Van originally had a straighter hinge in early models) you would have to have a slot cut in the forward skin in order for the j hinge to lift and clear the aircraft--with no slot I don't see how it could be jettisoned in flight (hmmm--wonder what it would do to the tail if it would jettison). I chose not to install at all for the reasons that you mention -- prime panel real estate and much of the unit is steel (weight). My switches are installed where the handle would have protruded through the panel. I installed 1/4" steel pins with securing clips on the ends as hinges. If I need to remove the canopy I pull the pins--which is harder than the panel mounted handle but I will take the slight inconvenience for the panel space and wt recovery.

Hope this is of value!

Cheers,

db

Mel · #6 02-25-2007, 06:55 AM

The jettison can still be utilized, but there are several things that have to be considered. The forward slots have to be cut, but then they are covered with tape similar to what sailplanes use to cover the wing root. You must remove the struts when doing acro or flight testing, or any other time you will be wearing a parachute. I have the jettison with the original canopy hold up. I don't like the struts. I do recommend that you install the mechanism at least. Even if you don't run it through the panel, it will still come in handy for maintenance as other have stated.

cytoxin · #7 02-25-2007, 07:14 AM

mine is installed per plans.

airguy · #8 02-25-2007, 08:22 AM

Quote:

Originally Posted by db1yg

(hmmm--wonder what it would do to the tail if it would jettison).

Doesn't matter. If you jettison, you're about to bail, and the tail (and everything else) now belongs to the insurance company. I would be happy to discuss with the NTSB after the fact what exactly happened to the tail, and why.

db1yg · #9 02-25-2007, 04:59 PM

That ground discussion is preferable, assuming that the very object that removed the VS has not also removed all or a portion of the "pilot processor containment device". Then that parachute looses all usefullness!!!

Lets just hope none of our RV driver friends ever have to test this in flight!!! Now get that appropriations bill approved!

Look me up the next time you are in the SAT area--I am at Bulverde airpark (1T8).

Cheers,

db

grantcarruthers · #10 02-26-2007, 07:56 AM

Would any of you jettison in your "emergency off field landing checklist" just in case of a tip over.

I personally would to avoid being trapped upside down in my -8.

So in that case I hope the tail makes it through the jettison (I highly doubt it wouldn't) since I won't neccessarily be done flying when/if I jettison the canopy.

Or do you just pack a crash ax and beat your way out in case of a tip over???

And if that's your choice then will the same canopy disassembly procedure work in an acro-bail-out event and ditch the jettison cost/complexity/weight/time to build penalties.

How about a poll??