Honest Pre-flight safety video

There are three things I do when on a plane.

1) Count the number of rows to the nearest exit row, both in front of me and behind me. I might be seated immediately behind the exit row, but that's not going to do me any good if the crowd is surging toward the rear of the plane.

2) Stay seated except when necessary (bathroom trips), and always keep the seat belt on when seated. A little turbulence at 500 miles per hour can send you flying up out of the seat. Wearing a seat belt is uncomfortable? Better than getting a cracked skull.

3) Understand decompression, its causes, its effects, and the emergency oxygen system.

Let's start with its causes. Remember the bomb scene in Airport (1970)? Some people think that's the usual cause of decompression, except that instead of it being a bomb, it's some sort of structural failure -- a door or window fails (very loudly) and suddenly there's a loss in pressure, the O2 masks drop, et cetera. But far more common are pressurization system failures where a valve gets stuck open or something similar happens. That's what killed Payne Stewart and the others on his plane. And when that happens, there won't be a bang or other such event; the O2 masks will simply drop. Unfortunately, there have been cases when this has happened and passengers, believing that decompressions are always accompanied by loud bangs, conclude that the O2 system has deployed erroneously, that all is actually well, and do nothing.

Physiologically, the effects are hypoxia -- loss of capacity for rational thought -- followed by unconsciousness, then death. Estimates for the amount of time you have to act are usually based on Air Force test data and other such sources. But that data is collected from young, healthy test subjects in pressure chambers who know the event is happening. For the rest of us, the time to act may be considerably less. In extreme circumstances you might have as little as ten seconds of useful consciousness. At the end of that time you'll still be conscious, but you'll be so scatterbrained you won't be able to act to save yourself.

Airplanes are normally pressurized to the equivalent of being at 8000 feet altitude. The masks don't drop until the pressure has dropped to 14000 feet equivalent. That's much higher than what most of us are used to. This means that unless you're a Himalayan Sherpa, you're already impaired when the masks drop, already considerably down that slope which may be as short as ten seconds.

The video depicts a high speed descent after a decompression, to quickly get to a lower altitude where the air is breathable without supplemental oxygen. But what if the airplane is over high mountains when the decompression happens, and it takes somewhat longer to get to a lower altitude? Or what if the decompression is caused by structural failure, and a high speed dive means possibly overstressing an already damaged airplane -- and the extent of the damage can only be inferred?

Finally, consider that the emergency oxygen system typically has a capacity of twelve to fifteen minutes. Ultimately the pilot might have to rely upon that length of time to get the plane to safety. Well, if you got the mask on, you'll be fine. But if you didn't and nobody was able to come to your assistance, by the time you get to that lower altitude you'll at least have some serious brain damage.

What this all adds up to is this. If those masks drop, you cannot take even a moment to wonder what's going on and why it's happening. You might have that time available, but you can't assume that you do. You must grab that mask immediately. You must activate the O2 system immediately. You must jam your face into the mask immediately. You must do all these things immediately or you might die.

It's important to understand how the O2 system is activated. See this diagram: https://en.wikipedia.org/wiki/File:Aircraft_oxygen_generator_diagram.svg

That's the most common type of emergency oxygen system. Note that the masks have gas hoses connected to the O2 system, but they also have lanyards which are connected to a retaining pin. When that pin is pulled out of place, the "purcussion [sic] cap and firing mechanism" are activated, starting a chemical reaction which produces oxygen as a byproduct. So the goal is simple -- get the pin out of its socket. Also note that all the lanyards are connected to the same pin, so if any person in your row of seats gets the pin out, it activates the system for everyone in your row.

I saw this the other day. It’s fake. Really bad distortion doesn’t make it sound like a planes AV system.