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-   -   Jettisoning a canopy (https://vansairforce.net/community/showthread.php?t=135717)

Gash 03-15-2016 11:27 AM

Have any of our aeronautical engineers here ever been able to estimate the load on the back of the canopy at various airspeeds? I wouldn't know where to begin on a calculation like this.

It would seem that in a bailout situation with adrenaline pumping, a pilot might be able to unstrap and push up on the unpinned canopy with the shoulders and upper back to force it off. This is of course if the air load is not too high.

rvbuilder2002 03-15-2016 12:39 PM

Quote:

Originally Posted by Gash (Post 1062468)
It would seem that in a bailout situation with adrenaline pumping, a pilot might be able to unstrap and push up on the unpinned canopy with the shoulders and upper back to force it off. This is of course if the air load is not too high.

It is only theory, but I don't think any pushing would be required.
There should be low pressure (lift) on the fwd end of the canopy and high pressure at the back (attempting to push it fwd).
As long as the occupant was able to un-pin both sides and then slide the canopy aft enough to get it out from under the overhang on the wind screen, I think the rest of the process would take care of it self (the reason I suggested that a hand not be inserted into the handle.......).

Berchmans 03-15-2016 01:30 PM

Reminder
 
And remember if you reach this point in your aviation experience that once that engine quits or your decide to leave the plane you no longer own it, the insurance company does...in the words of Bob Hoover, fly the plane as far into the crash as you can...

donaziza 03-15-2016 07:50 PM

that the sliding canopy for the RV-7 cannot support the body weight of the pilot when inverted when the pilot forgets to attach his seatbelt. Think you have too much experience to do this? This pilot had over 2300 hours.



Nobody is saying if this guy was wearing a parachute or not. I'm guessing he was, otherwise why jettison his canopy. I can't believe he forgot to fasten his seatbelt. My guess is he first undid his seatbelt, "THEN" tried to jettison his canopy. Then the canopy hung up on him, he rolled inverted, and was knocked out by hitting his still there canopy. Therefore, never opened his chute. (Same thing happened to a Marine Corps instructor in a T 28 many years ago)

OK, I'm going to get on my soapbox now. I've got an 8, not a 7, but I've got the quick release pip pins also. Since nobody knows for sure what happens when you try to jettison your canopy, my plan is to stay strapped in tight, "then" pull the canopy back a little and push up. (DO NOT insert fingers in canopy opening---too many reports here of it slamming back shut) Everybody talks about this pressure on the canopy, so I don't know if pushing up will work or not---but one could try to slow down first and then push. Then when you "know" what its like to fly without a canopy, then unstrap, roll inverted, fall out and hope your kneecaps come with you (since they partially stick under the instrument panel). OK, I know what you're all saying----a heck of a lot to think about if you're panicked.

But I don't know what other option one would have. I've sat on the ground and rehearsed these steps in the proper order, so I wouldn't have to think much about it if say I caught fire or whatever.

I'm gonna guess this is exactly what this guy did, only his canopy didn't leave his plane properly, and his body weight is what took it off.

What say you guys out there?

skylor 03-15-2016 08:04 PM

Quote:

Originally Posted by donaziza (Post 1062591)
---but one could try to slow down first and then push. Then when you "know" what its like to fly without a canopy, then unstrap, roll inverted, fall out and hope your kneecaps come with you (since they partially stick under the instrument panel).

If one has this much of control of their airplane, I honestly don't think they would be considering bailout in the first place...unless it was a bad fire, but I don't think fire is the primary reason people where chutes during aerobatics.

Skylor
RV-8

rapid_ascent 03-16-2016 09:17 AM

That pull strip should also reduce the number of people asking for rides too.:D


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