Something that all regular fliers will be familiar with in the pre-flight safety announcement is what to do with the oxygen masks.
"To start the flow of oxygen pull the mask gently towards you."
Sounds nice and simple, unless you're trying to do that while a rapid decompression is taking place at over 30,000 feet in the air.
A rapid decompression is an unplanned drop in the pressure of a sealed environment and can happen if the plane door is opened mid-flight, or if a window is smashed. However, as The Telegraph points out, the majority of these uncontrolled decompressions happen due to failures in the plane's structural integrity, or inadequate repairs.
But if the plane door was to open mid-flight, "anyone standing near the exit would be ejected into the sky; the cabin temperature would quickly plummet to frostbite-inducing levels, and the plane itself might even begin to break apart," airline pilot Patrick Smith told The Telegraph.
During a rapid decompression at cruising altitude, most adults will reportedly have between 15 to 20 seconds of useful consciousness. That may sound like enough time to pull an oxygen mask towards you and maybe even to assist the child next to you, but with rapid decompression, you have a lot more to deal with.
A member of the PPRunE aviation forum named Superpilot described what it is like for a pilot to go through a rapid decompression: "Your tongue is swallowed by your throat in a second, your ears begin to hurt, and teeth become a hundred times more sensitive.”
If you don't instantly pass out, one of the biggest risks is hypoxia, where the body is deprived of oxygen and will lead to disorientation, unconsciousness, lowering heart rate, and eventually death.