I read an account quite a while back of a KR-2 accident where the plane flipped and the occupants were trapped inside. Luckily, this happened at an airport and folks rushed out to flip the plane and get them out, but the whole thing did give me something to think about. Planes do end up on their backs sometimes even in easily survivable mishaps, and it would be a bad thing to be hanging in the straps, smelling the 100LL, and wishing that there were a way out.
I think one of the occupants in that same KR-2 accident also suffered a head injury when the canopy cracked and his head contacted the ground. This brings home the fact that a rollover structure (behind the seat or as part of the windscreen frame) is a good thing, but may not be totally effective if your harness allows the head to be up against the canopy when the plane is upside down.
I like low-wing designs and believe a bubble canopy has some safety advantages (visibility, less likely to jam in a crash than a door), but have been thinking that gull-wing canopy/doors may offer some advantages. It allows a central brace to tie the windscreen frame to the rollover structure behind the seat, and with removable pin hinges either door could be removed for quick egress (provided the inverted plane is tipped to one side, which seems likely).
Some military aircraft carry a "canopy breaker tool" to be used by occupants to chip a hole through the canopy if it fails to/can't be jettisoned. Better than nothing, and I'm sure the efforts of the occupants would be spurred by their motivation to get out, but this always struck me as something that sounded good to a designer but would be a nightmare in actual use.
Am I overthinking this? There are lots of happy Van's owners out there. I don't have any numbers on how frequently these rollover accidents happen, but it does seem that having one way out via a single large piece of plastic might be a liability.
I think one of the occupants in that same KR-2 accident also suffered a head injury when the canopy cracked and his head contacted the ground. This brings home the fact that a rollover structure (behind the seat or as part of the windscreen frame) is a good thing, but may not be totally effective if your harness allows the head to be up against the canopy when the plane is upside down.
I like low-wing designs and believe a bubble canopy has some safety advantages (visibility, less likely to jam in a crash than a door), but have been thinking that gull-wing canopy/doors may offer some advantages. It allows a central brace to tie the windscreen frame to the rollover structure behind the seat, and with removable pin hinges either door could be removed for quick egress (provided the inverted plane is tipped to one side, which seems likely).
Some military aircraft carry a "canopy breaker tool" to be used by occupants to chip a hole through the canopy if it fails to/can't be jettisoned. Better than nothing, and I'm sure the efforts of the occupants would be spurred by their motivation to get out, but this always struck me as something that sounded good to a designer but would be a nightmare in actual use.
Am I overthinking this? There are lots of happy Van's owners out there. I don't have any numbers on how frequently these rollover accidents happen, but it does seem that having one way out via a single large piece of plastic might be a liability.
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