15 November 2020

Defenestration

"In 1990, a panel of the windscreen on British Airways Flight 5390 fell out at 17k feet, causing the cockpit to decompress & its captain to be sucked halfway out of the aircraft. The crew held onto him for more than 20 minutes as the copilot made an emergency landing. The pilot made a full recovery."

"If I remember correctly, the accident happened because someone eyeballed the screws when they replaced the window, and they were like a millimeter off."

Pretty close. The screws used to secure the windshield were different lengths for different areas. Instead of using a template to know where each screw came out of or referring to the IPC (illustrated parts catalog) they just put the screws in a pile and slammed them back in without ever knowing if the screws were actually grabbing enough threads on the nutplates."
Comments from the discussion thread at the nevertellmetheodds subreddit.  I don't have a link to a primary source.

The embedded photos are not from the incident, but rather from a National Geographic reconstruction of the incident.  Hat tip to reader Charlie for doing the detective work.

10 comments:

  1. Where did these photos come from? Hard to believe even if someone had a camera they would take the time to use it under the circustances. And even if they did how did they get that angle on the scenes? this was before selfie cellphone cameras so the interior shot seems unlikely. And the exterior shot seems unlikely too. And they don't seem self consistentent since it is said he was held by the belt no the ankles. Anyone holding his ankles in the window would be frost bitten not just on the hands but the face making that likely impossible to maintain. I'm thinking these must be from some movie recreation or something.

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  2. These are not photos of the actual incident. They are taken from a National Geographic recreation http://home.bt.com/news/on-this-day/june-10-1990-miracle-of-ba-flight-5390-as-captain-is-sucked-out-of-the-cockpit-and-survives-11363985642960

    You can get a clue that this was the case for the following improbable details. 1. he was held onto by his belt not his ankles. 2. the camera angle from inside the cockpit seems unlikely as no one could be in that location, selfie cell phones did not exist in 1990, and who would bother to take pictures at a time like that when they could be helping hold the captain. 3. the outside picture seems even more improbable as a photo opportuinity 4. the person shown in the photos would have frostbitten hands and face if they were really that outside the cockpit. 5. the pilot would have an airmask on in such a situation, and there would be all sorts of shit flying about, not a neatly pressed shirt and tie. (look at their ties)

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  3. Also one more wrong detail. The missing window in the photos is not the correct one. You can compare those photos to the real photo of the broken window here http://home.bt.com/news/on-this-day/june-10-1990-miracle-of-ba-flight-5390-as-captain-is-sucked-out-of-the-cockpit-and-survives-11363985642960

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    Replies
    1. Thank you for that info, charlie. I also wondered about who took the photos, but was too busy/lazy to look it up this morning.

      Text amended.

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  4. WOAH! Imagine if that happened now, the footage would go viral within a day, multiple lawsuits would be filed (maybe they were?) and that pilot would be able to make a living appearing on tv shows. Wonder if he's still alive?

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  5. The screw design is what made me shake my head. Why in the world wouldn't you standardize the length of the screws/holes to the size of the largest one needeed? That way, it wouldn't matter which screw went where on the windshield.

    It was too precious by half...and apparently almost lost someone their life.

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    Replies
    1. I agree, when I worked in industry I had standards as to (in our case size not length) what screws I could use in a design "because the guys on the floor can't handle anything smaller than a #8.

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    2. The screws were not different sizes. The mechanic found that the wrong screws were in place, so he replaced them. Unfortunately, he replaced them with screws that were also too short, by less than half a millimeter.

      -Accident investigators discovered that when the windscreen had been refitted to the plane the night before, the wrong bolts [sic] had been used to secure it; they were little more than half a millimetre too small, and had failed under intense air pressure.

      From the linked article:
      -The bolts had actually replaced other incorrect ones; the engineer, working under pressure and without reference to manuals, had simply replaced the old bolts with new ones on a like-for-like basis.
      -As a result of the incident, windscreens on British Airways planes are now secured by bolts on the inside of the plane, rather than the outside, putting them under even less pressure.

      I worked as an aircraft mechanic for 10 years (proud graduate of Pittsburgh Institute of Aeronautics) prior to starting my teaching career. Working as a mechanic for a major carrier is a stressful job, as you are constantly under pressure to turnaround the aircraft without delay. While most mechanics are conscientious, some are not. The redundancy built into most systems keeps flying as safe as it can be.

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  6. That Nat Geo recreation would make for a pretty good paint scheme.

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  7. I'd always had it that defenestration was an act perpetrated by another person, such as when the CIA orchestrated a regime change (and this was a favored outcome for them)- they tossed folks out the window! More recently, we've seen this in Russia, where outspoken heads of nursing or doctor cadres have wound up many floors downstairs, via the balcony, after having made critical or disparaging remarks about how the Covid pandemic was being mis-managed.

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