Alaska flight incident reveals another feature Boeing didn’t inform pilots about - Federal investigators said that Boeing didn’t make pilots aware that when a plane rapidly depressurizes, the cockp…::undefined

  • @[email protected]
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    9611 months ago

    I had thought that since the 2001 hijackings it has been basically impossible to open the cockpit doors during flight, except from the inside. On El Al planes I’d heard it was impossible period, so hijackers couldn’t threaten their way in, but US carriers didn’t want to do that because it means the cockpit needs its own lavatory, displacing a few passenger seats.

    • Shadow
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      11 months ago

      In the case of an explosive decompression, you can’t have that wall trying to resist the pressure difference. It’ll blow in a horrible way and probably destroy a ton of circuitry / wiring.

      It needs to fail open like this, that design makes sense. The pilots should have been informed though.

      An attacker could probably leverage that though to get into the cockpit.

      See https://admiralcloudberg.medium.com/a-legal-and-moral-question-the-crash-of-turkish-airlines-flight-981-and-the-dc-10-cargo-door-saga-d22f0b9fa689

      • @[email protected]
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        5911 months ago

        If that design is necessary it has presumably always been like that on every pressurized plane ever built. So it shouldn’t have been a surprise. But, some vents should be able to equalize the pressure without opening the door.

        ISTR hearing that El Al planes had separate entrances for the cockpit and passenger compartment so there was no way to enter or leave the cockpit except on the ground. No door, just a reinforced wall. But maybe that was a post-911 urban legend.

        • @[email protected]
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          3911 months ago

          Aircraft maintenance has been doing the negative pressure unlock tests on cockpit doors for decades, its honestly surprising what isn’t common knowledge. Like others have said, rapid decompression of only a portion of the aircraft is very bad, and will result in massive structural failure as individual compartments aren’t pressure rated and will blow apart. The doors I’ve had experience with had large panels that would pop out when in a negative pressure event.

        • brianorca
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          11 months ago

          There are surely some vents that could handle a slower decompression, but a sudden event that reduced the pressure by half in a single second would be too much. 6 tons is a lot of force for a door to take, especially when it is in the opposite direction of most threats the door is supposed to stop.

        • @[email protected]
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          311 months ago

          But, some vents should be able to equalize the pressure without opening the door.

          “some vents” are simply too small.

          • @[email protected]
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            1011 months ago

            Then make them larger.

            It’s not even technically challenging. Just a couple tubes of appropriate diameter with a dog leg in them if they’re too large. Or multiple small tubes. It’s a few psi (IIRC planes are about 10psi at altitude, approx a 7psi differential from outside at 40k ft cruise altitude) albeit a large volume. But the cockpit volume is relatively small, so doesn’t take much time to equalize, and once it starts to equize, the force from pressure drops quickly, probably non-linearly.

            Decompression in planes is awfully exaggerated in movies.

        • BoscoBear
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          211 months ago

          Seems like a burst disk in the bulkheads would be a better solution than counting on a door to pop open.

        • BarqsHasBite
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          111 months ago

          Cockpits would need their own bathroom, food, and maybe sleeping area if they had no door. Can’t see that happening.

      • Uriel238 [all pronouns]
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        411 months ago

        As per pre-911 we just may need to discourage hijackers from attacking planes through other vectors, not that the TSA is an actual deterrent. It’s difficult to believe our current measures take terrorism seriously.

    • @[email protected]
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      1411 months ago

      Guess that wasn’t good enough

      In June, the FAA announced it will require a secondary barrier between the passenger cabin and cockpit of new commercial planes that are manufactured starting in the summer of 2025.

      That was at the end of the article. Not sure why but that pisses me off. Probably cause it seems purely like an act based out of fear rathe than in response to any threat/weakness

    • CrimeDad
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      1211 months ago

      The problem with locking cockpits is that is that it’s perfect for an evil or very sick pilot.

        • CrimeDad
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          11 months ago

          Yup. If you think about it, that flight was the fifth to be brought down by the 9/11 hijackers. The FAA just gave them a freebie.

      • exu
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        311 months ago

        I think some airlines require a pilot to switch with one of the board crew when they leave the cockpit.

        • CrimeDad
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          111 months ago

          I hope so, but an evil pilot still only has to subdue that one person.

          • @[email protected]
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            111 months ago

            Subdue, while flying a plane? The only way I can picture that working is if they casually pulled out a gun and executed the other person before they realized. Pilots also have to go through a security line for employees… It’s far from impossible to get past that, but it’d take planning…

            Suicide is a fixation on a method of death, then following through in the moment

    • @[email protected]
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      511 months ago

      US carriers didn’t want to do that because it means the cockpit needs its own lavatory, displacing a few passenger seats.

      Did they say that to the FAA?