Anyone who has flown on a commercial airline has heard it.
"In the event of a decompression, an oxygen mask will automatically appear in front of you," the Federal Aviation Administration-required announcement goes. "To start the flow of oxygen, pull the mask towards you. Place it firmly over your nose and mouth, secure the elastic band behind your head, and breathe normally."
Judging by the passengers of Southwest Airlines flight 1380 which had to make an emergency landing in Philadelphia Tuesday after one of its engines failed, killing a passenger, few are paying attention.
Debris from the engine hit a window, shattering it. The sudden decompression pulled a passenger partially out of the window. She died from her injuries.
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Video and photos taken inside the plane show passengers holding the masks over their mouths, but not their noses. Many, it appeared, were not using the elastic bands.
It's no doubt chaotic and frightening during an in-air emergency. Some people may have other things on their minds.
But the incident raises the question: Is anyone listening during those speeches?
Flight crews also tell passengers to use their seat belts when seated even if the seat belt sign has been turned off. Yet, passengers are occasionally injured when planes hit turbulence so severe it throws them out of their seats.
According to data from an airline training manual, rapid decompression at 30,000 feet — which flight 1380 was at — can deprive passengers of breathable air in 30 to 60 seconds. That makes it crucial that passengers immediately put on oxygen masks when the masks fall from the ceiling.
Data from flightaware.com shows pilot Tammie Jo Shults put the plane into a rapid descent on Tuesday. She descended 20,000 feet in just over five minutes as a cabin pressure alarm blared in the cockpit.