3 ms·

On first blush, isn't this an application of the Birthday Paradox? If stuff-falling-off-planes is a birthday event that happens at random, if it happens 23 time

On first blush, isn't this an application of the Birthday Paradox? If stuff-falling-off-planes is a birthday event that happens at random, if it happens 23 times a year you'll get two happening on the same day every other year on average. Eg if you pick a year (say, the 365 days ending today), if there were 23 stuff-falling-off events you'd have a 50% chance of two havjng happened on the same day. If it happens 10 times a year, the chance they coincide is 12%, which means it will happen more than once every decade. It's only when you get down to 5 times a year that it gets really unlikely to overlap... That said, uncontained engine failures do seem to be rare enough that two of them specifically coinciding really is very unlikely but in the realm of "weird coincidence" unlikely and not "supernatural" unlikely.

TylerE 6y ago
I also would suspect this sort of minor incident is much more common than most people realize. When you have no passenger injuries these things don't usually make the news.
- silvestrov 6y ago
  How many passengers are even aware of contained engine failures? There can be a lot more failures than people think. I'd guess most people are also bad at estimating how many car accidents there are in a year.
  - oivey 6y ago
    In the case of a contained engine failure, don’t planes immediately land at the closest safe location? Passengers would definitely know.
    - TylerE 6y ago
      Usually, but that can be very far way. Look up ETOPS.
    - crote 6y ago
      It depends. The Denver one [0] basically landed straight away at the same airport 40 minutes later. The Maastricht one [1] circled around for an hour, and landed on a completely different airport. The whole "immediate" and "closest" is relative. Strange as it may seem, an engine failure isn't that big of a deal: the aircraft is designed to fly for hours while missing an engine. However, the aircraft is now in a bit of an unknown state. The pilots need time to work through their checklists, determining what the exact impact is. The airplane might be leaking fuel; it might've lost a set of hydraulics; maybe it's on fire; maybe the engine can be restarted and everything is fine. Landing as soon as possible at the closest safe location might turn out to be hours later and hundreds of miles away, perhaps even at your destination airport! [0]: https://uk.flightaware.com/live/flight/UAL328/history/20210220/1925Z/KDEN/PHNL https://uk.flightaware.com/live/flight/UAL328/history/202102... [1]: https://uk.flightaware.com/live/flight/LGT5504/history/20210220/1525Z/EHBK/EBLG https://uk.flightaware.com/live/flight/LGT5504/history/20210...
      - oivey 6y ago
        The point was often the plane would land somewhere that isn’t their destination, which would at least clue them into the fact that there was some significant mechanical issue.
  - topspin 6y ago
    > How many passengers are even aware of contained engine failures? All of them. If they somehow miss the noise and vibration, they'll definitely notice the fire and/or smoke trailing out of the engine. Compressor failures aren't minor events. If it happens during certain phases of flight the asymmetric thrust can create a severe challenge for the crew. More than one airliner has crashed as a result. Asymmetric thrust due to an autothrottle problem may be why Sriwijaya 182 (a 737) crashed last month.
- deleted 6y ago
  [deleted]

TylerE 6y ago

I also would suspect this sort of minor incident is much more common than most people realize. When you have no passenger injuries these things don't usually make the news.

silvestrov 6y ago
How many passengers are even aware of contained engine failures? There can be a lot more failures than people think. I'd guess most people are also bad at estimating how many car accidents there are in a year.
- oivey 6y ago
  In the case of a contained engine failure, don’t planes immediately land at the closest safe location? Passengers would definitely know.
  - TylerE 6y ago
    Usually, but that can be very far way. Look up ETOPS.
  - crote 6y ago
    It depends. The Denver one [0] basically landed straight away at the same airport 40 minutes later. The Maastricht one [1] circled around for an hour, and landed on a completely different airport. The whole "immediate" and "closest" is relative. Strange as it may seem, an engine failure isn't that big of a deal: the aircraft is designed to fly for hours while missing an engine. However, the aircraft is now in a bit of an unknown state. The pilots need time to work through their checklists, determining what the exact impact is. The airplane might be leaking fuel; it might've lost a set of hydraulics; maybe it's on fire; maybe the engine can be restarted and everything is fine. Landing as soon as possible at the closest safe location might turn out to be hours later and hundreds of miles away, perhaps even at your destination airport! [0]: https://uk.flightaware.com/live/flight/UAL328/history/20210220/1925Z/KDEN/PHNL https://uk.flightaware.com/live/flight/UAL328/history/202102... [1]: https://uk.flightaware.com/live/flight/LGT5504/history/20210220/1525Z/EHBK/EBLG https://uk.flightaware.com/live/flight/LGT5504/history/20210...
    - oivey 6y ago
      The point was often the plane would land somewhere that isn’t their destination, which would at least clue them into the fact that there was some significant mechanical issue.
- topspin 6y ago
  > How many passengers are even aware of contained engine failures? All of them. If they somehow miss the noise and vibration, they'll definitely notice the fire and/or smoke trailing out of the engine. Compressor failures aren't minor events. If it happens during certain phases of flight the asymmetric thrust can create a severe challenge for the crew. More than one airliner has crashed as a result. Asymmetric thrust due to an autothrottle problem may be why Sriwijaya 182 (a 737) crashed last month.
deleted 6y ago
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