Dangers of Lifejackets
 

A friend was recently flying across the channel in a tandem seat motorglider wearing lifejacket, parachute and of course the seat harness. Half way across the bl**dy lifejacked inflated itself. Luckily she could still breathe and was able to puncture it with a ball point pen.
What would you do?

You should be able to push the `oral inflation` valve in with a pen or little finger and deflate it to a more comfortable size.....Try before fly....

I would deflate it with the valve in the mouthpiece intended for that, so it could be reinflated again later (and indeed, not have to be replaced. If it was an automatic lifejacket, that's a poor idea in a plane, always use manual inflation lifejackets only.

With only lap and diagonal straps, it didn't trouble me when I caught the inflator tab and it inflated. On the ground, doing hecks. Deflated with top-up tube. Gave me a shock though.

It has inflated under your chin so you cant look down plus you have two lots of straps to negotiate. You cant even see the inflation tube

Did she not read the instructions of the vest?

If done properly, the pull cord should remain covered, so it cannot be pulled accidentally. Being such unfamiliar with the vest and its built in valves that she punctured a working vest with a pen does not sound like proper pre-flight too.

So, number one, if the vest is properly operated, it should not inflate accidentally; number two, if it blows, there are mouth pieces to manually inflate as well as deflate the vest to adjust the air fillings to your need. I would do a proper instruction on how to handle a vest as first action.

The jacket did not inflate itself. The release was pulled and it functioned as designed.

Somewhere on the internet there is a picture of a Cherokee or similar where someone did the same with a liferaft.....

Reading the instructions, taking care usually works. The inflation tube is unsurprisingly located in the upper stole so it can be easily reached by mouth and is unlikely to be trapped when inflated......