Take a water egress course
If you're seriously concerned about this (i.e. you often fly over large bodies of water) I'd highly recommend a water egress course. I think the FAA still offers one in Oklahoma City for free or cheap, and there are private companies who offer them as well. The course instructor(s) may even have an answer to your question -- at least generically.
I took a mini egress course at the Puyallup (WA) conference a couple years ago, and it was quite an enlightening experience. After some classroom work, we were each flipped over upside-down in a mock-up cockpit floating on 4 feet of water (in our street clothes for added realism!). The mock-up cockpit had Cessna-style seatbelts/shoulder-strap (and door/door-handle), and I was surprised to learn how easy it is to get tangled up in those things once under water and upside-down, and it's even worse if there's current in the water (or your plane is sinking). In air you can just unbuckle and shake yourself loose, but in water they'll twist and wrap around you and tangle enough that you may have a hard time freeing yourself. It was one of those things that I didn't believe until I experienced it for myself. Fortunately there were instructors in diving suits ready to help me out, but I made it on my own after some struggling. In that class we learned that one type of seatbelt in particular -- where your shoulder harness ends has slots in them and they slide onto the main buckles -- will almost certainly kill you under water. A 5-point quick-release is best for water egress if I remember correctly.
Anyway, take the class. You'll learn some good stuff. And if they answer your RV-specific question(s), post here!
__________________
Shannon Miller
RV-7A Fuselage
|