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

  • 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.

      • @[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.

      • 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.

      • 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.