Escape hatch?

[kgwilson]

RD,

 

Agreed that your suggestion would improve the strength and load distribution but you could go on forever and just keep adding weight. The turtledeck in itself is structural and strong 032" 6061 sheet riveted every 10mm to the bulkhead and of course to the longerons. I think the combination of all the factors including the tail triangulated support is sufficient. The Sierra airframe is very strong. I have seen some photos of a Sierra crash where the Jab3300 was smashed back under the firewall & ended up facing backwards and the rest of the A/C was almost unrecognisable except for the airframe around the cockpit area. The pilot walked away & would have had hardly any injuries if there was no fire.

 

 

[turboplanner]

KG, Rocketdriver was pointing out a valid engineering point, which would only require one short length to fix - about the same weight as your shoes.

 

HOWEVER, before playing with a proven space frame, engineering calculations need to be done to ensure that stiffening the frame at this point is not going to inhibit the flex of the space frame to the point where there is a potential for cracking.

 

I would be asking Gary if he would approve a tube running from the top rail down to the point where the vertical and diagonal tubes meet.

 

If he approved that, then the weakest link would be the structure above the top rails, and I would consider replacing the two separate angles which at the moment are only tied to each other by sheetmetal, so can twist, with a structural tube roll bar. This would not be hugely expensive, and the aircraft could then withstand a much heavier thump.

 

 

[Guest Howard Hughes]

You might get away with a small gnome-sized axe but CASA won't allow you to carry weapons remember

I have one of these in my aircraft, all with CASA's approval!:thumb_up:

 

Only problem for RAA is, it weighs as much as a small child!

 

 

[Litespeed]

I am liking Rocket Drivers idea of a perspex hatch for escape.

 

Maybe a mod on this idea is for a cut line in the screen that almost goes through the surface in a suitable area for escape. In the event of roll-over the thin amount of screen at the cut could be broken out more easily. It maybe a more easy way out in a panic and much easier than breaking the full thickness of the plastic.

 

If the cuts are in a gull wing shape on each side this might be the best for exit.

 

Completely out of left field is this idea-

 

A small battery powered oil or air or screw ram that is attached to the rear of the roll bar and in a rollover allows the airframe to be pivoted up and provide some escape space. Would be very firmly attached to the airframe/rollbar structure and have a a large pad at its top.

 

Activation would be by cable pulls in easy places for a injured pilot.

 

So- pilot flips plane- now upside down with a aircraft sitting on rollbar.

 

Large pad connected to ram pushes the airframe upwards 12-24".

 

Pilot smashes out remaining canopy which has a relief cut built in.

 

Pilot escapes.

 

Such a system would allow the pilot space to get free when all contorted up side down.

 

Weight would be quite small as modern rams could be very strong in a small light package.

 

Out of the box I know but could be a goer.

 

Phil

 

 

[turboplanner]

Good lateral thinking Litespeed, something like an oversize gas strut using an aluminium tube with a gas release switch.

 

 

[turboplanner]

How's this, cut out a panel in the canopy/upper sheetmetal.

 

Refit the panel using H Section rubber extrusion.

 

To escape, just push the panel out. "escape" sign upside down at the top if you want.

 

Escape.pdf

 

Escape.pdf

 

Escape.pdf

[Litespeed]

sorry triple post

 

Damn puter made me do it.

 

two of them removed - Mod

 

 

[Guest rocketdriver]

How's this, cut out a panel in the canopy/upper sheetmetal.Refit the panel using H Section rubber extrusion.

To escape, just push the panel out. "escape" sign upside down at the top if you want.

That was my initial thought, but reckon the low static pressure on the outside will suck the panel out, hence the thought of a soft wired pin in a piano hinge at each end of the escape panel. If the panel is, if you like, all the way over the top of the cnopy , then the emergency pull pins could be at sill height .....

 

cheers

 

 

[Litespeed]

Good lateral thinking Litespeed, something like an oversize gas strut using an aluminium tube with a gas release switch.

Yeah, that's the idea- have it ready to fire at any time. With a locking mechanism to stop it dropping back down.

 

Maybe even have it extended on final for landing as insurance. Once you land and stop, retract it. The more I think about it the better I like it.

 

The idea is a bit like the pop up roll bars modern convertible cars have.

 

Never crashing does not seem a option so any progress would be great.

 

Another idea would be gas powered bags to lift the plane of its canopy, one just in front of canopy and one behind.

 

Phil

 

 

[Guest rocketdriver]

Never crashing does not seem a option so any progress would be great.Phil

Actually, never crashing seems like a good idea to me ... I've done it twice, once with an experimental hang glider (fractured a vertebrae and still have after effects, tho' with workarounds) and one with an experimental a/c ...(fractured the wallett). Neither a great experience at the time, although something to look back upon I suppose ....

RD

 

 

[Guernsey]

I recon that all I would need is a crash helmet as I would become an adrenalin powered rocket man:helmet:

 

Alan.

 

 

[Litespeed]

But Alan your rocket exhaust is in your pants. You will just drive you head into the ground.

 

Make sure you eat lots of beans to provide sufficient thrust.

 

 

[Wayne T Mathews]

Not very good for pretty. But pretty good for effective.

 

 

 

[Wayne T Mathews]

Of course then there is the proven Ballistic 'Chute. Starting to sound like essential in a low wing bubble canopy.

I used to like the idea of ballistic chutes.

 

 

[Litespeed]

Not very good for pretty. But pretty good for effective.

Nice axe Wanye.

 

Might be a bit hard to swing upside down though. Oh and don't hit yourself or passenger.

 

Be useful on a wood aircraft.

 

 

[facthunter]

Sorry, but the ballistic chute would be a serious hazard in a landing flip over. It's an armed missile in those circumstances. The invert is usually caused by a collapsed nosewheel or such and you don't see it coming.. Nev

 

 

[Steve Donald]

I wonder if there would be any market for a small device that through some magic of materials science could cut or fracture perspex easily with minimal power such as muscle power and batteries.....

Hiya guy,s what about a cordless angle grinder small and light, you would be out in a jiff as long as no fuel is leaking or you will be a jiffy fire starter, yep escape is a worry i sold my low wing for the same reason i stopped taking the kids in in it, i will stick with the Jab

 

 

[Guest Jake.f]

The idea of a canopy that could be broken by hand could work, but I imagine it would weaken the canopy a lot. There would be the risk then of the canopy somehow fracturing in flight.. Then there is the question of is the chance of the canopy fracturing in flight greater than the chance of flipping over on the ground. What would happen in most low wing aircraft if the canopy were to break and fly off? If they can still be flown I imagine that taking the small chance of that happening would be worth it to avoid the scenario of ending up upside down in the middle of nowhere with little chance of being found alive.

 

For a relatively simple problem not many solutions seem simple (Except for the axe idea of course)

 

 

[Wayne T Mathews]

Sorry, but the ballistic chute would be a serious hazard in a landing flip over. It's an armed missile in those circumstances. The invert is usually caused by a collapsed nosewheel or such and you don't see it coming.. Nev

When BRSs first came out, I thought they were a great idea... Not anymore... As Nev has said, it's an armed missile... I asked one bloke where his safety pin was so I could put it in before bringing his aircraft into my hangar. He didn't know. He'd never used it. And the chute was time expired for Christ sake.

 

Personally, I now think BRSs have the potential to cause far more harm than good.

 

Wayne.

 

 

[facthunter]

BR, there are definate situations where the B chute would be literally a life saver, the best example being a mid air collision , or hitting a ski lift wire in the Alps in Switzerland. Regarding the area being unsuitable for a forced landing that might not provide a reasonable chance of survival, what are you doing over such tiger country in a single engined plane? We still don't have the reliability where you should disregard the advice.."If you can't land on it , don't fly over it"..

 

In single engined planes, I divert significantly to avoid particularly, high timbered country with tall trees and steep slopes. The chance of landing there without serious injury is nearly zero. Not sure you would do a lot better with a bal. chute in that situation either. On the occasions where you have to I reduce the exposure by going the shortest distance at the greatest height. Some people think that is wimpy, but I'm happy to wear that. Nev

 

 

[djpacro]

My thoughts would be two sections of the bubble canopy (one on either side) should have a fusible outline (yes it would weaken the canopy) but in a part of the canopy that does not flex. This would be marked by an outline with words like "Push out in an emergency".

4 g limit load factor is 6 g ultimate - you might be surprised at how much aerodynamic load is on the canopy at 6 g. An airplane with a half decent certification basis would need to prove that the canopy would not break at the ultimate load factor of the airplane.

[turboplanner]

Interesting FH, until I started RA flying I'd never heard of "Tiger Country", and certainly never flight planned the Cherokee over bush without regular clearings.

 

 

[facthunter]

The term has been around since I started flying, but I don't know how much common usage it gets. Nev

 

 

[pudestcon]

BR, there are definate situations where the B chute would be literally a life saver, the best example being a mid air collision , or hitting a ski lift wire in the Alps in Switzerland. Regarding the area being unsuitable for a forced landing that might not provide a reasonable chance of survival, what are you doing over such tiger country in a single engined plane? We still don't have the reliability where you should disregard the advice.."If you can't land on it , don't fly over it"..In single engined planes, I divert significantly to avoid particularly, high timbered country with tall trees and steep slopes. The chance of landing there without serious injury is nearly zero. Not sure you would do a lot better with a bal. chute in that situation either. On the occasions where you have to I reduce the exposure by going the shortest distance at the greatest height. Some people think that is wimpy, but I'm happy to wear that. Nev

You are speaking common sense I reckon Nev - pure and simple.

 

Pud

 

 

[Wayne T Mathews]

You are right of course Nev. Going the long way round to avoid the tigers is the only responsible thing to do and it is good to be reminded of the maxim..........Where the judgement call comes in is when you have an open area where you could land without hitting trees or fences but are flying a low wing aircraft and have to make a call whether you think you can get it down without a stall/spin or flipping onto the lid or do you just take the "easy" option and yank on the red lever.

A succint summary Don....

 

I'm wondering if anybody else has thought about what happens if "she who must be obeyed" gets the poohs with you and.... Sorry, I just can't bring myself to say it.

 

Keep the sunny side up,

 

Wayne.