question -bubble canopies /protection in aircraft flipping over.

[dazza 38]

I was ready qwerty's thread on tiger country. He brought up a interesting point about the aircraft nosing over in a emergency landing.(hitting a ditch etc.) Does anybody think of posibility of it happening and avoiding those type of aircraft that may not be structually as strong as say a high winger compared to a low winger.example- the tecnam golf's windsreen/canopy is designed to take the weight of the a/s when upside down. i think other manufacturers may not have this design feature. Personally i do not worry about it, if it may happen it is a risk im willing to take. How do other people feel?

 

 

[Guest watto]

I am sure the high wing would have a little more structural integrity in this situation given this part of a high wigh supports the majority of stress produced by the wings, but in saying that polycarbonate is an extremely stong material and I know from previous employment that you could fire a 38 bullet at a polycarbonate riot shield and it would extrude around the bullet but did not crack or allow penetration and was almost impervious to repeated blows with batons and steel pipe etc and although thicker that the canopy of an ac this gives you some evidence of the punishment it can withstand.

 

 

[dazza 38]

hi watto, i remember when training for my gfpt in the archer, i was taught that in a emergency landing ie- engine failure -i should open the door and wedge the door open with a shoe or something similar (before landing) because if the A/C flipped over or their was structural damage. the door wouldn't open and you will be trapped inside. Watto , with A/C with canopies that open upwards hinged from the front i guess one of those emergency hammers (the ones with a spike) would be sufficient to break the canopy so you could escape if upside down. what do you reckon?

 

 

[Guest watto]

I would be surprised if a spike hammer would get you out in a hurry as polycarbonate does not tend to shatter, you would need to hack a section out I would think. But I would not really want a geopick floating around the cockpit either! it would need to be stowed away securely somewhere.

 

Polycarbonate does saw very well and maybe a good leatherman tool with a saw attachment would be the best way of simply cutting a hole if time permitted.

 

You have raised a good point though as far as actually getting out of the upturned ac if the canopy was to remain in tact, it could prove difficult and unlike a technam or jabiru or similar high wing there is only one way out.

 

 

[Yenn]

I don't think I would fancy sawing my way out. Something quicker is required. a lot of GA planes are equipped with escape tools ie. hammers. My personal method would be to part open the canopy and make sure it couldn't re latch and it would also probably break in the starlet, ot the fibreglass frame would shatter.

 

 

[Guest watto]

Yenn, the starlet's sliding system would propably let go in an impact and perhaps be forced back. You could fairly quickly hack a hole I suppose it depends on your condition and how much room you have to work in, it's like everything, you design for a specific type of incident but every incident has variables that affect how they work at the time.

 

LSA seem to be pretty safe and a lot of people walk away from these type of mishaps so that has got to say something about the design quality.

 

 

[dazza 38]

The chances of the scenario that we have been discussing, of it happening is pretty slim. But it can happen. Thank you for your imput. I guess it is up to the individual pilot to think about what they would do, if encounted with the situation.

 

 

[Guest watto]

That's true, it all come down to what your situation is and what each of us evaluates as the immediate course of action.

 

Good post though.

 

 

[Guest Maj Millard]

dazza38, It can happen, and it does happen. I personally have had to make immediate exits out of aircraft on two separate occasions, and believe me you think quick, and move even quicker !!. You move even quicker if there is fuel dripping, or a possiblility of fire, not to mention ending arsx up in water. Your survival instinct is a very powerfull thing, when you need it to be !. The suggestions of sawing your way out, forget it, even though those suggestions are well ment, it just doesn't happen that way.

 

Right after an incident the adrenalin is pumping full time, and you just want out...now !!.

 

Were I to own a low wing aircraft with a bubble type canopy, I would definitly carry an easy locatable, powerfull device for going through the canopy..quickly. Be it a hammer , small axe ...whatever. If you don't have it when you need it, then it may not end up being your best day. Remember also that once lexan or acrylic is cracked or shattered, your legs can be used to kick out panels quite effectivly .........I carried a very sharp knife on my gear for 10 years as a skydiver, never used it once, but it could have saved my life had the need arose.................................................

 

 

[Guest ozzie]

low wings don't offer much in a flip over. pretty common in a off airport forced landing smallish wheels rough terrain flip over and if you have a short tail the canopy hits the ground the frame gives. if you still have a head. maybe a shovel would be of more help. even worse if the fin post collapses. now they are fitting airbags to aircraft maybe a popup rollbar like those in convertables these days might be the trick.,

 

 

[HEON]

Hard to have general rule on high/low wing as some address the problem.

 

Lightwing Speed (low wing) has steel tube frame (=roof strength), gull wing doors (=cannot be opened in flight), but pull cords to remove door hinge pivots/joiner in emergency.

 

 

[Guest Maj Millard]

I was in the Lightwing factory a week ago, must say the Speed is looking real impressive these days.....keep up the good work Howie and the boys................

 

................................................................:rilla:

 

 

[Thruster87]

I would be surprised if a spike hammer would get you out in a hurry as polycarbonate does not tend to shatter, you would need to hack a section out I would think. But I would not really want a geopick floating around the cockpit either! it would need to be stowed away securely somewhere.Polycarbonate does saw very well and maybe a good leatherman tool with a saw attachment would be the best way of simply cutting a hole if time permitted.

 

You have raised a good point though as far as actually getting out of the upturned ac if the canopy was to remain in tact, it could prove difficult and unlike a technam or jabiru or similar high wing there is only one way out.

Tell that to a fellow who is on his third canopy as he keeps cracking it while trying to fit/drill it to his aircraft.These bubble canopies do crack very easily if there is a stress riser and the consistency of strength/malleability is not equal throughout,the forming process may be responsible for this .Cheers

[Guest watto]

Good on you Major, it's great to have advice from a person who has been in the situation themselves as it is difficult to speculate on how it will pan out in the event should it occur.

 

It is amazing how adrenalin kicks in during these few moments and I guess you can only hope that if it does occur.

 

I hope I never need experience this scenario but I always feel ready to take on any challenge for survival should it arise.

 

 

[Guest watto]

Tell that to a fellow who is on his third canopy as he keeps cracking it while trying to fit/drill it to his aircraft.These bubble canopies do crack very easily if there is a stress riser and the consistency of strength/malleability is not equal throughout,the forming process may be responsible for this .Cheers

That's interesting with that stuff, it must be in the way it is formed as you can get some sheets that are as tough as buggery and other stuff that crack when you drill it as you have said, the main lexium I have had dealings with is much thicker and a very high grade and steel frame chairs and iron bars just bounce off with little more that a schratch.

 

What was noted though was that if it was well fitted it is much harder to damaged than if you had a loose corner or a nick along the cut edge.

 

 

[skybum]

Watched an incident at Tyabb when an RV flipped after a runway incident. Both guys were trapped inside the cockpit with the flip forward bubble canopy. Design principle for me would be a means of rollover protection for a seated/strapped in crew(CT4) and then another means of jettisoning the canopy before the incident. Pulling the pins of the front hinge and pushing up whilst the aircraft is still moving and upright.

 

A guy in the US has modified his pax control stick in his RV with a pick welded on the removeable stick base as a means of getting out of his bubble canopy in case of a roll-over.

 

 

[Guest watto]

I have a powerpoint of an RV-7 standing on it's nose amongst the photo's if anyone can tell me how to separate this photo from the presentation I will post it.

 

 

[slartibartfast]

This one?

 

 

 

[Guest watto]

Thats the one, maps strategically stored on the canopy!

 

 

[slartibartfast]

They had this on the big screen frequently during the SAAA dinner on Saturday night with a running competition to find the best caption.

 

The only one I can remember right now was,

 

"You said if we followed the GPS the runway would be right on the nose."

 

 

[Guest watto]

It's an amazing shot as you can still see the turf flicking up from around the prop and one blade departing as she is obviously still running.

 

No worries about falling out as the sphinkta would be suctioned onto the seat by then I'd reckon!

 

 

[dazza 38]

excellent photo, i hope the guys where alright. Hi Maj, i guess when the adrenalin, kicks in anything is possible (in regards to getting out).

 

 

[DarkSarcasm]

a running competition to find the best caption.The only one I can remember right now was,

"You said if we followed the GPS the runway would be right on the nose."

That would be a fun thread to start....

 

 

[Guest Maj Millard]

dazze 38, yes mate you are correct. We have capabilities and survival instincts that you would not believe, unless you have used them. It's like the brain goes into overdrive, almost leaving you behind. I was in an unfortunate crash in 1974, in a Cessna 182 jump plane. We lost power completly right after take off, and crashed horribly into trees at the end of the runway. The two gentlemen in the front were killed on impact, and the lady in back with me was badly injured. I was the only one capable of exiting the plane, although also injured . Even though I was sitting right next to a large opening (the RH cabin door off), in one instant I smelt fuel, heard a ticking coming from the engine, and went out over the injured girl, through a jagged crack in the LH fuselage side, cutting myself up in the process on the torn aluminum...but I got out, because as my brain was processing the fuel smells, my eyes saw grass through that crack and that's where I went. It's impulsive and very strong !!. The lady made a good recovery also, and now lives in Perth. We still communicate often...................maj

 

 

[Guest ozzie]

yeah it was the smell of fuel that motivated me in a C180 that ground looped and went over on it's side snapping a wing off. not a jumpship so both doors were on. i was sitting in the back. i went out thru the pilots window. beat the two in the front.

 

there is a short period of WTF i suppose then you just go move into high gear. The thing i really remember was the noise that poor beast made as it hit the ground several times then slid on it's side across the ashphalt. Then lots of quiet. Those lap belts aren't much chop. got a few bruises and bumps and really sore shoulder. pilot broke his wrist from the column being ripped out of his hand. caused by dum dums getting up it straight out of the taxi way. tail came up when turning and it hopped from wheel to wheel a couple of times the round we went. this was at BK in '79.

 

ozzie