5 ms·

There might be another loose bolt issue, this time in the rudder control system: https://www.faa.gov/newsroom/faa-closely-monitoring-inspections-boeing-737-max-

by pajko 3y ago

There might be another loose bolt issue, this time in the rudder control system: https://www.faa.gov/newsroom/faa-closely-monitoring-inspections-boeing-737-max-airplanes https://www.faa.gov/newsroom/faa-closely-monitoring-inspecti...

imglorp 3y ago
A failed door plug might kill several people. A failed rudder will kill all of them.
- jsharf 3y ago
  I think planes can still fly with the rudder loose? If the bolt falls out and it loses control, wind will push it into the neutral position and then flying will still be possible with other control surfaces? But I guess if the pilots don't know and it happens suddenly at a critical moment or if the bolt causes the rudder to get jammed, then that would be really bad. But I assume it falling out would result in the rudder loosely returning to neutral...
  - sokoloff 3y ago
    There have been rudder-caused crashes in the past, on the 737. (That's not that shocking as the 737 is a very high production airframe.) https://en.wikipedia.org/wiki/Boeing_737_rudder_issues https://en.wikipedia.org/wiki/United_Airlines_Flight_585 https://en.wikipedia.org/wiki/USAir_Flight_427
  - SoftTalker 3y ago
    The rudder is necessary for directional control specifically turns, and for flying straight in a crosswind. I've heard of a few cases where applying more/less power on the right/left engines can sort of crudely achieve the same thing, and you might get lucky and get on the groud without crashing, but loss of the rudder would be a serious emergency indeed.
    - addaon 3y ago
      > The rudder is necessary for directional control specifically turns, Only if you add a secondary constraint of coordinated turns, which are important for passenger comfort and efficiency, but not directly a safety concern. (You still need directional stability, but that's provided by the fixed portion of the vertical tail, not the rudder.) > and for flying straight in a crosswind. Only if you add a secondary constraint of alignment between body angle and flight path. This constraint is totally absent in normal flight -- it only comes up during takeoff and landing, where it's useful to have the plane lined up with the runway to avoid side-loading the landing gear. In the case of a known rudder failure, you'd head to an alternate where there's not much crosswind, to avoid this issue; but you wouldn't expect many issues getting there. The third case where the rudder is actually critical is when combined with other failures, especially asymmetric engine failures. There are parts of the flight envelope where a single engine failure combined with a rudder failure would not be expected to be survivable.
      - bombcar 3y ago
        In fact, the rudder does not do what new pilots think it does (it is NOT like a boat rudder at all, really, because the plane banks) that instructors will often make you practice flying without using the pedals at all.
      - geonineties 3y ago
        I always find that a little odd. Wouldn't you be able to cut thrust on the working engine and just be a glider?
  - addaon 3y ago
    Planes can fly with the rudder inoperable, although with some restrictions -- you wouldn't want to do a serious crosswind landing, and you wouldn't want to stack it up with other failures, especially asymmetric engine failures. However, that doesn't mean that planes can fly with the rudder /loose/. A significant risk in higher-speed airplane designs is that of aerodynamic flutter, where aerodynamic forces excite a vibration mode in the airframe, or a subset of it. You can find some impressive video of e.g. bending modes in sailplane wings being excited, with increasing magnitude bending until the wings are destroyed (or the excitation is reduced dramatically, or shifted to a different frequency). While aeroelastic modes get a lot of attention in flutter analysis, loose control surfaces can be much, much worse, because movement of the surface within the lash provided by the loose connections is effectively undamped.
- MuffinFlavored 3y ago
  How did the airline know not to sit anybody in the seat right next to the door plug (who would have gotten sucked out and fallen to their death)? Like was it really just good luck nobody sat there? I'm so surprised people aren't more terrified to fly. So many different things can go wrong. I know what the statistics say about driving versus flying but I feel like over time with all of these Boeing issues that statistic is slightly changing for the worse? > According to the latest estimates, there are approximately 100,000 flights per day. This number includes all types of flights, including passenger, cargo, and military aircraft. Passenger flights alone account for over 90,000 flights per day, transporting millions of passengers to destinations all around the world. I guess 365 days a year, 100k flights a day, 1 incident is really statistically low but... it's still terrifying to put yourself in a metal tube in the sky where the risk is non-zero you die!
  - bombcar 3y ago
    Door plugged seats maybe don't have a window or something that makes that row less desirable, so it gets filled last. As to the flight terror, we're mainly scared of it for two reasons: 1. Disasters seem personally unavoidable - you can choose to drive better, etc, so any car accidents you see you can comfortably think you would have avoided. But once you're in the metal tube, you have no control over the results. 2. When it happens, it's rare and big news everywhere for weeks.
    - reddit_clone 3y ago
      There is also the primal fear of falling down (I often have dreams of falling down and get jolted awake). Another major issue is the awareness and helplessness. In a car accident everything happens so fast, you only have time to go 'On Sh..'. Sometimes not even that. Some people get T-Boned and die without knowing what happened. But in case of an airliner, usually you know well ahead of time something is wrong. Engines are visibly on fire, there is fire in the cabin, it is flying side ways, it is lurching all over the place, it is spinning out of control.. etc. You have time to panic , scream, curse and cry. Personally this is what terrifies me.
- _cenw 3y ago
  Already has its own Wikipedia page with examples of what happens when your rudder flops around uncontrolled too. https://en.wikipedia.org/wiki/Boeing_737_rudder_issues https://en.wikipedia.org/wiki/Boeing_737_rudder_issues
kingTug 3y ago
"We at Boeing apologize for the door accident. Let us reassure you with a rational explanation: Basically it went all weird, due to nails being a bad size or maybe shape. It went wonky or something. Because the metal bits were wrong and/ or small or possibly the wrong type/ kind. "

by pajko 3y ago

imglorp 3y ago

A failed door plug might kill several people. A failed rudder will kill all of them.

jsharf 3y ago
I think planes can still fly with the rudder loose? If the bolt falls out and it loses control, wind will push it into the neutral position and then flying will still be possible with other control surfaces? But I guess if the pilots don't know and it happens suddenly at a critical moment or if the bolt causes the rudder to get jammed, then that would be really bad. But I assume it falling out would result in the rudder loosely returning to neutral...
- sokoloff 3y ago
  There have been rudder-caused crashes in the past, on the 737. (That's not that shocking as the 737 is a very high production airframe.) https://en.wikipedia.org/wiki/Boeing_737_rudder_issues https://en.wikipedia.org/wiki/United_Airlines_Flight_585 https://en.wikipedia.org/wiki/USAir_Flight_427
- SoftTalker 3y ago
  The rudder is necessary for directional control specifically turns, and for flying straight in a crosswind. I've heard of a few cases where applying more/less power on the right/left engines can sort of crudely achieve the same thing, and you might get lucky and get on the groud without crashing, but loss of the rudder would be a serious emergency indeed.
  - addaon 3y ago
    > The rudder is necessary for directional control specifically turns, Only if you add a secondary constraint of coordinated turns, which are important for passenger comfort and efficiency, but not directly a safety concern. (You still need directional stability, but that's provided by the fixed portion of the vertical tail, not the rudder.) > and for flying straight in a crosswind. Only if you add a secondary constraint of alignment between body angle and flight path. This constraint is totally absent in normal flight -- it only comes up during takeoff and landing, where it's useful to have the plane lined up with the runway to avoid side-loading the landing gear. In the case of a known rudder failure, you'd head to an alternate where there's not much crosswind, to avoid this issue; but you wouldn't expect many issues getting there. The third case where the rudder is actually critical is when combined with other failures, especially asymmetric engine failures. There are parts of the flight envelope where a single engine failure combined with a rudder failure would not be expected to be survivable.
    - bombcar 3y ago
      In fact, the rudder does not do what new pilots think it does (it is NOT like a boat rudder at all, really, because the plane banks) that instructors will often make you practice flying without using the pedals at all.
    - geonineties 3y ago
      I always find that a little odd. Wouldn't you be able to cut thrust on the working engine and just be a glider?
- addaon 3y ago
  Planes can fly with the rudder inoperable, although with some restrictions -- you wouldn't want to do a serious crosswind landing, and you wouldn't want to stack it up with other failures, especially asymmetric engine failures. However, that doesn't mean that planes can fly with the rudder /loose/. A significant risk in higher-speed airplane designs is that of aerodynamic flutter, where aerodynamic forces excite a vibration mode in the airframe, or a subset of it. You can find some impressive video of e.g. bending modes in sailplane wings being excited, with increasing magnitude bending until the wings are destroyed (or the excitation is reduced dramatically, or shifted to a different frequency). While aeroelastic modes get a lot of attention in flutter analysis, loose control surfaces can be much, much worse, because movement of the surface within the lash provided by the loose connections is effectively undamped.
MuffinFlavored 3y ago
How did the airline know not to sit anybody in the seat right next to the door plug (who would have gotten sucked out and fallen to their death)? Like was it really just good luck nobody sat there? I'm so surprised people aren't more terrified to fly. So many different things can go wrong. I know what the statistics say about driving versus flying but I feel like over time with all of these Boeing issues that statistic is slightly changing for the worse? > According to the latest estimates, there are approximately 100,000 flights per day. This number includes all types of flights, including passenger, cargo, and military aircraft. Passenger flights alone account for over 90,000 flights per day, transporting millions of passengers to destinations all around the world. I guess 365 days a year, 100k flights a day, 1 incident is really statistically low but... it's still terrifying to put yourself in a metal tube in the sky where the risk is non-zero you die!
- bombcar 3y ago
  Door plugged seats maybe don't have a window or something that makes that row less desirable, so it gets filled last. As to the flight terror, we're mainly scared of it for two reasons: 1. Disasters seem personally unavoidable - you can choose to drive better, etc, so any car accidents you see you can comfortably think you would have avoided. But once you're in the metal tube, you have no control over the results. 2. When it happens, it's rare and big news everywhere for weeks.
  - reddit_clone 3y ago
    There is also the primal fear of falling down (I often have dreams of falling down and get jolted awake). Another major issue is the awareness and helplessness. In a car accident everything happens so fast, you only have time to go 'On Sh..'. Sometimes not even that. Some people get T-Boned and die without knowing what happened. But in case of an airliner, usually you know well ahead of time something is wrong. Engines are visibly on fire, there is fire in the cabin, it is flying side ways, it is lurching all over the place, it is spinning out of control.. etc. You have time to panic , scream, curse and cry. Personally this is what terrifies me.
_cenw 3y ago
Already has its own Wikipedia page with examples of what happens when your rudder flops around uncontrolled too. https://en.wikipedia.org/wiki/Boeing_737_rudder_issues https://en.wikipedia.org/wiki/Boeing_737_rudder_issues

kingTug 3y ago

"We at Boeing apologize for the door accident. Let us reassure you with a rational explanation: Basically it went all weird, due to nails being a bad size or maybe shape. It went wonky or something. Because the metal bits were wrong and/ or small or possibly the wrong type/ kind. "