When the left engine blew on Southwest 1380, a woman was almost sucked out of the plane through the broken window by her side, other passengers on the flight told NBC. It seems impossible, and officials have not yet confirmed the reports, but before they had sucked damaged aircraft.
The engine of the Boeing 737 exploded Tuesday morning as the plane flew from LaGuardia airport from New York to Dallas, forcing the pilot to make an emergency landing in Philadelphia. One passenger died, the National Transportation Safety Board said at a press conference, and the Philadelphia fire department reported several injuries. But NTSB spokesman Keith Holloway told The Verge in an email that he had no information about the reports of a passenger who was almost removed from the plane in mid-flight.
While fatal air accidents are extremely rare, there have been cases of passengers being sucked out of airplanes punctured before, says Thomas Anthony, director of the aviation safety and security program at the University of Southern California. In 1989, for example, a cargo door left United Airlines Flight 811 and took part of the fuselage with it: nine passengers were sucked from the plane.
That can happen because the interior of the plane is pressurized, so people can breathe even when the plane goes up to lower air pressures at higher altitudes. The pressure differences between the interior and the exterior of the airplane cause suction, says Anthony, that could take a passenger from an airplane if it is punctured. The higher the plane, the greater the pressure difference, Anthony says: "Then, the more dangerous the condition is, and, no doubt, the bigger the hole."
The Verge spoke with Anthony about cabin pressures, rare but fatal plane crashes and oxygen masks.
This interview has been edited for clarity and brevity.
What exactly does it mean when a plane is depressurized?
The term used in the industry is "rapid depressurization". The point of pressurization of an airplane is to keep the air inside the airplane at a level where people can breathe comfortably. And so, in general, as the altitude increases, the air pressure [outside] decreases. Therefore, commercial aircraft are maintained at a pressure altitude of approximately 8,000 feet so that people can comfortably breathe air. When a hole is drilled, there is less pressure, there is less oxygen, and that is when the oxygen masks come down.
How does a rapid depressurization occur? Are there specific conditions when it is more or less likely that an airplane will depressurize quickly?
Okay, yes. If there is a puncture on the aluminum skin, or in the case of a modern aircraft, composite skin. In the case of intentional acts of unlawful interference against aviation, that is, in cases where the bombs were placed on board the aircraft, then the hole in the side of the aircraft would be much larger, and in some cases a person has The plane was sucked.
Is it different when depressurization occurs due to a small perforation like a bullet, compared to a large hole?
Yes, it's different. Let's say a bullet is fired, which will cause depressurization, but it would not be the same as, say, a structural failure that causes a large hole. Think of the Aloha Airlines case, where the top part of the plane came out. Aloha operated a fleet of planes, in this case, 737, which went from island to island. Take a tight takeoff, and a landing, to pressurize the fuselage and then depressurize it.
And because there were so many takeoffs and landings from island to island and because it was in a hot and humid environment, there was corrosion on the upper part of the skin that formed the fuselage, and actually the upper parts of the fuselage were peeled off to make it look like like the top part of the plane disappeared completely when it landed. There was a fatality of a flight attendant, who was sucked out of the plane, but a surprising number of people survived that.
What is the safest seat to sit on if a plane depressurizes quickly?
I have not thought much about that, but I think it all depends on the location of the depressurization. But, in general, I would say that it would be that seat that is closer to the middle of the plane, like a corridor seat [because] you are further from the side.
How do you breathe when the plane is depressurized before putting on the mask? Should you try to hold your breath?
No, you do not have to hold your breath, there's still oxygen there. You are simply absorbing less of that. What you have is a useful time of conscience to pull [mask] down and put it on. So no, do not hold your breath, just act in a normal way, pull it down and breathe in oxygen.
Is it possible for depressurization to break the plane?
That question can be answered by the fact that this phenomenon is unknown to us. So, if it's not a "no," it's a "do not approach" because in my profession of studying accidents since the introduction of jets, this is not something we've seen. Therefore, it is extremely, extremely unlikely. [With] Aloha's flight, you will see that the plane continued to land safely even though the upper part of the fuselage had disappeared. That speaks of the structural integrity of the aircraft.