Think about it, you ditch and the aircraft starts to sink with you in it. The LJ auto-inflates whilst you are still inside the aircraft.
This is a very valid point, and generally I agree. In the particular amphib, in which I do much of my water flying, this is not an issue, as entry/exit is a quite large space of side and roof on both sides of the aircraft. An inflated lifejacket won't slow things down. That said, in most "cabin" type cockpits, an inflated lifejacket inside is undesireable, for all of the stated reasons.
I have just been given 3 good quality jackets, with one problem; they have both manual and auto inflation. However, it seems that the auto-inflation is a seperate module that screws onto the bottom of the mechanism inside the jacket; and, I can unscrew it! Does anyone see any problem with doing this, and then using the jackets as standard manual ones?
The most common type I see (Mustang brand is the example I have) involve a heavy spring held back by a small yellow plastic disc with something like sugar or salt in it. When wet, it dissolves, and the spring is released. It punctures, the CO2 cylinder, and boof, you're bouyant! (and have to spend $30). Unscrewing this part is a non-event. When flying Cessnas on floats, or the helicopter, I'd change to manual all the time. When I take my six year old out on the boat, automatic, in case I go overboard. The manual is just a screw on protective cap, that allows manual only operation (and can't go off when left alone in the plane!). Mine's manual now!
There were virtually no incidents where it could be proven that LJ had made any positive contribution.
I surely agree! But listen for the cries when you go public with a plan to remove them from airliners! False security, left over from "Titanic" mentality!
On the other hand though, I vote that
wearing a life jacket be
mandatory for any occupant of a "small" vessel, or other device operating on the water. There are many too many drownings where the victim would be with us, were they to have been wearing a life jacket, or at least the search for the body would have been very much quicker. I have done many of these searchs over the last 20 years. Outcome was
always negative for those not wearing life jackets.
Always positive for those who were. Absolute statistics!
If going into the water is a possibility,
wear a life jacket. If you go in, you won't have time in the water to go in the back to try to find it!