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In April this year, a passenger was partially sucked out of a plane window in the US, following an engine failure. This morning we awoke to the news that the co-pilot of a Chinese carrier was partially sucked out of the plane's cockpit. All in all, bad news for those of us who had hoped window-suckage on planes was a mere urban myth.
But knowledge is power: how does it happen, and more importantly, is there anything we can do to stop it happening to us? We asked Dr Nicholas Hutchins, a researcher at the University of Melbourne and expert in things like "turbulent boundary layers", what measures we might take to avoid this hell-on-earth scenario.VICE: Hi Dr Hutchins! As someone who is already afraid of flying, this is genuinely terrifying. How does it happen?
Dr Hutchins: The pressure inside the aircraft is higher than the aircraft outside, so passengers can breathe comfortably and don't suffer from altitude sickness, hypoxia, etc. If the fuselage is punctured, the pressurised air from inside the cabin will try to escape at high velocity. This is why people and objects can occasionally get sucked out. The pressure imbalance between the inside and the outside is quite large, so the velocity of the air exiting the aircraft—in this case through the broken window—can be pretty terrifying, and the forces on objects close to this exit can be very large.Please tell me this is very, very rare?
I would say that, as terrifying as this is, it is pretty rare. Otherwise it wouldn’t be newsworthy enough for us to discuss. Cabin depressurisation is quite rare, as is any type of aircraft failure. There have been a few notable incidents over the decades, but it is usually a secondary effect that is caused by some other failure. However, despite the rational side of me knowing that this is so, the story does make me more inclined to heed the advice to “keep my seatbelt fastened at all times when seated."I've noticed when I'm flying that there are actually two window panes with a gap between them, do both need to be broken for the window to be sucked out?
I think in the case of [the entire construction was broken. My feeling is that only the outer panes have any real mechanical strength. The outer window is typically double thickness, and has some kind of failsafe design. On the inside of this, there is typically a thin window plastic cover, which is probably the layer you are referring to, which would seem to have little mechanical strength [and] is probably just there to keep passengers' hands away from the actual window. In this particular case, I would say that some foreign object, by the looks of it probably something ejected from the engine, pierced the window, leading to a rapid depressurisation. It's pretty likely that if that object had hit some other part of the fuselage, it would also have pierced it and led to a similar rapid decompression of the aircraft. Perhaps the real issue here is why something was ejected from the engine.This makes me wonder why planes have windows in the first place. Would they be safer without them at all?
Good point. Certainly, in the jet age, windows have been one of the failure points in the fuselage, but modern designs have taken care of this. For example, early square windows on the comet jet aircraft had disastrous consequences. But windows do make the design of the fuselage that much more complicated. Engineers are not typically enthused at the idea of putting windows or hull penetrations in a pressure vessel. It would certainly be cheaper and easier to build aircraft without windows—but I am not sure that passengers would be very enthused about flying on them, which, I suspect, is why aircraft have them. There are a few concept designs around on drawing boards for windowless aircraft designs. I guess that screen and camera technology have now advanced to a point where one could argue that passenger windows are becoming redundant.Having said all of this […] aircraft windows are extremely strong and extremely safe. If these stories weren’t extraordinary, I doubt we would be discussing it. Perhaps that knowledge will provide some comfort next time we get a window seat.
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Dr Hutchins: The pressure inside the aircraft is higher than the aircraft outside, so passengers can breathe comfortably and don't suffer from altitude sickness, hypoxia, etc. If the fuselage is punctured, the pressurised air from inside the cabin will try to escape at high velocity. This is why people and objects can occasionally get sucked out. The pressure imbalance between the inside and the outside is quite large, so the velocity of the air exiting the aircraft—in this case through the broken window—can be pretty terrifying, and the forces on objects close to this exit can be very large.Please tell me this is very, very rare?
I would say that, as terrifying as this is, it is pretty rare. Otherwise it wouldn’t be newsworthy enough for us to discuss. Cabin depressurisation is quite rare, as is any type of aircraft failure. There have been a few notable incidents over the decades, but it is usually a secondary effect that is caused by some other failure. However, despite the rational side of me knowing that this is so, the story does make me more inclined to heed the advice to “keep my seatbelt fastened at all times when seated."I've noticed when I'm flying that there are actually two window panes with a gap between them, do both need to be broken for the window to be sucked out?
I think in the case of [the entire construction was broken. My feeling is that only the outer panes have any real mechanical strength. The outer window is typically double thickness, and has some kind of failsafe design. On the inside of this, there is typically a thin window plastic cover, which is probably the layer you are referring to, which would seem to have little mechanical strength [and] is probably just there to keep passengers' hands away from the actual window. In this particular case, I would say that some foreign object, by the looks of it probably something ejected from the engine, pierced the window, leading to a rapid depressurisation. It's pretty likely that if that object had hit some other part of the fuselage, it would also have pierced it and led to a similar rapid decompression of the aircraft. Perhaps the real issue here is why something was ejected from the engine.This makes me wonder why planes have windows in the first place. Would they be safer without them at all?
Good point. Certainly, in the jet age, windows have been one of the failure points in the fuselage, but modern designs have taken care of this. For example, early square windows on the comet jet aircraft had disastrous consequences. But windows do make the design of the fuselage that much more complicated. Engineers are not typically enthused at the idea of putting windows or hull penetrations in a pressure vessel. It would certainly be cheaper and easier to build aircraft without windows—but I am not sure that passengers would be very enthused about flying on them, which, I suspect, is why aircraft have them. There are a few concept designs around on drawing boards for windowless aircraft designs. I guess that screen and camera technology have now advanced to a point where one could argue that passenger windows are becoming redundant.Having said all of this […] aircraft windows are extremely strong and extremely safe. If these stories weren’t extraordinary, I doubt we would be discussing it. Perhaps that knowledge will provide some comfort next time we get a window seat.