My Safety Concerns About Bubble Canopies

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Twodeaddogs

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Getting flipped and trapped in my 650 bubble canopy is a long way down on the list of ways I can kill myself in the plane. It's also generally easier to flip taildraggers than it is to flip tricycle gear aircraft like the 650. Provided there's no fire my primary concern would be making sure I had an adequate supply of snacks while sitting on the bubble canopy waiting for help to arrive.
Unforunately, RV nosewheelers have shown a tendency to topple over. I am inspector on one that did just that when it ran off the end of a runway. The height of the fin kept it from crushing the canopy but it had to be lifted up with a tractor to free the pilots. It was rebuilt and is back in service.
 

Daleandee

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JayKoit

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Thanks to everyone who has contributed so far on this thread. It’s given me quite a few ideas as to how to make a bubble canopy design safer. I think when the time comes for the canopy stage of the build, I’ll be able to design a nice reinforced canopy with emergency egress options built in.
 

Daleandee

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0.014 fillet radius on the failed Sonex crank...
Correct ... but to be accurate it wasn't an Aerovee crank that failed. Not to pick on any particular company but the article also gave this for information:

The registered owner who was also the passenger's brother stated that the engine for N244HB was purchased as a kit from Great Plains Aircraft Supply Company. The kit consisted of engine parts that he assembled from supplied instructions/plans. He said there was no engine serial number. He said that the maintenance work to the lifters cited in the aircraft logbook was due to a notification from Great Plains Aircraft Supply Company for pitting of the engine lifters. The camshaft as well as the crankshaft had to be removed when work to the lifters was performed. The crankshaft bearings and the crankshaft were never changed since the engine was first assembled.
Tom was a really great guy and yes ... he is still missed by many! He was a master at making flying related videos:

[video=youtube;ShlWr6P41xg]https://www.youtube.com/watch?v=ShlWr6P41xg[/video]

For more of Tom's videos: https://www.youtube.com/user/tomhuebbe/videos

Dale
N319WF

PS: Apologies if this is a bit too far off topic
 
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lr27

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Thanks to everyone who has contributed so far on this thread. It’s given me quite a few ideas as to how to make a bubble canopy design safer. I think when the time comes for the canopy stage of the build, I’ll be able to design a nice reinforced canopy with emergency egress options built in.
Escape hatch in the bottom of the plane, just like an ocean going trimaran.
 

BJC

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While I encourage safety in aircraft design, I must admit to having mixed reactions to specific safety concerns, such as the one being discussed in this thread. Some examples:

I have flown airplanes with the fuel tank just above my knees. Almost everyone would agree that fuel in the cockpit is unsafe, but consider that the collective features of one of those designs makes it an airplane that I would need to work really hard to cause a structural failure (a concern for much of my flying) and it also makes it an airplane that I can recover from any flight condition and is so controllable that extreme crosswinds are not a factor. It has a canopy that may be opened in flight. Many pilots routinely open the canopy for takeoff and or landing. I did too, for some time. Then I concluded that the absence of wind in the cockpit was, for me, more of a safety factor than having an open canopy.

A good bubble canopy may provide the visibility to reduce the chances of a mid-air collision. Depending on the type and place of your flying, a mid-air may be a greater risk than getting trapped above a bubble canopy.

Some believe that a tailwheel airplane poses is a greater risk of injury or death from a landing flip over. A neighbor’s husband was killed in his RV-6A when, during a hard landing on a grass runway, the nose wheel strut snapped off, causing a flip. During construction, he had mis-drilled the windshield frame / roll-over protection to such a degree that it crushed.

Whole airplane parachute systems are generally considered a safety system, and they have saved people. I question whether or not they affect the decision making of the pilot. And, like many safety additions, they add weight.

Doing anything within the realm of personal transportation involves risk. How much risk is a function of the equipment (or animal) being used, the experience of the user, and, perhaps most significantly, the judgement of the user.

These comments are not intended to shut down the discussion in this thread; rather, they are intended to encourage looking at personal airplane safety features as a combination of interacting issues.


BJC
 

Direct C51

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I don’t know about all canopies, but if you have a Sonex, just carry a bottle of rubbing alcohol. It sure cracked my canopy easily.
 

lr27

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Rubbing alcohol, just the thing for a plane that might be on fire. (Or else why do you want to get out fast?)
 

BBerson

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Lexan is sensitive to gasoline (and perhaps alcohol?)
You can't shatter a Lexan canopy, you need a saw or something.
So it depends if your canopy is polycarbonate or acrylic how you break through it.
 

lr27

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I understand that Lexan isn't as trasparent if you get bug repellent on it! I don't have the details, just an incident I read about. With a boat. Nobody got hurt.
 

Dana

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Chemicals may attack a plastic canopy, but not very fast.
 

mbauer

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Live in Nikiski, AK USA
Have a home escape kit multi-tool. Solid cast aluminum construction, hammer on one end, single claw as well, gas shut off valve wrench etc..

Hope I won't need it, but that is what is mounted under the canopy, side wall kangaroo pouch holds it out of the way, in my RV-6. Always wondered about the "swing" area available.

Been thinking about trying a carpenter's tomahawk.

Best regards,
Mike Bauer
 
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