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No, the failure mode is not two pilots consciously fighting against each other. The failure mode is two pilots who are UNAWARE they are commanding contradictin

No, the failure mode is not two pilots consciously fighting against each other. The failure mode is two pilots who are UNAWARE they are commanding contradicting inputs. Airbus negligently averages these inputs. This is legacy tech debt because the physical design didn’t leave room to link the two controls. Now they are stuck because they feel they can’t change and have some planes that (dangerously) average the inputs, and some that are physically linked. When controls are physically linked, if one pilot thinks he should nose up, and the other tries to nose down, they can yell “what are you doing” at each other and this create an accurate mental model of what the other is intending. Think of this every time you fly Airbus. It’s very similar to debugging a production technology issue. Imagine you decide to restore the database to a snapshot from 1 hour ago, and at the same time someone else tries to restore to an earlier snapshot from 12 hours ago. Should the system average these inputs and restore from 6.5 hours ago? No, obviously not.

SmellyGeekBoy 8y ago
> Think of this every time you fly Airbus. Why? They're not falling out of the sky so the system obviously works. Stop being a fanboy.
foldr 8y ago
>Now they are stuck because they feel they can’t change and have some planes that (dangerously) average the inputs, and some that are physically linked. This is a really weird way to construe the situation. The accident report doesn't conclude that the handling of dual inputs was a factor, and it's clear from the transcripts that it wasn't. Airbus has no reason to change this. Merely linking sidesticks would be pointless in any case, since sidesticks don't have an identifiable position (but are used with brief movements away from center). It's hardly any easier for a pilot to passively observe the movements of his own sidestick than it is just to look over at the other pilot's stick.
- neuronic 8y ago
  The commenter appears to have a vested interest in making Airbus look bad, otherwise the comment cannot be logically understood. Is there a case where the averaging of inputs has been proved catastrophic?
  - notfromhere 8y ago
    Air France 447
    - foldr 8y ago
      Not according to the official accident report. This is a meme spread by an article in Popular Mechanics that came out long before the official report.
deleted 8y ago
[deleted]
benhurmarcel 8y ago
> Airbus negligently averages these inputs. On an Airbus, in case of dual input the pilots get a voice alarm and a warning lights up right in front of them. Also the stick has a switch to take priority, in case the other pilot continues to give dual input.
- jandrese 8y ago
  Did AF447 not have this warning? One of the contributing factors to the crash was the copilot continuing to pull back on the stick even as the pilot attempted to push the nose down to get out of the stall.
  - livatlantis 8y ago
    I answered further up but: yes, it did. The DUAL INPUT alarms were audible in the cockpit voice recording. However, unbeknowst to the captain, the co-pilot used priority takeover on his side. (This was always visible on the panel + there was an audible "Priority right" warning around the end) Source: https://www.vanityfair.fr/actualites/articles/vol-af-447-rio-paris-reconstitution-des-minutes-qui-ont-precede-le-crash/23618 https://www.vanityfair.fr/actualites/articles/vol-af-447-rio...
    - foldr 8y ago
      I'm not sure where you're getting the "unbeknownst" from. In the cockpit voice recorder transcripts attached to the official accident reports, it seems that the pilots were aware of who had control at any given point in time.
      - jandrese 8y ago
        I remember right before the impact with the water the captain finally realizing why his controls aren't doing anything and asking the co-pilot to finally let go of his stick. IIRC they never did throttle up however. Ultimately the co-pilot got tunnel vision and thought for some reason they were in an overspeed condition for most of the incident and failed to communicate that effectively with the rest of the crew. He made a couple of comments about it, but nobody else realized that he was attempting to correct for an overspeed condition in the middle of a dead stall, even when the airspeed indicator came back it seemed wrong to him because he thought they were going too fast.
cjbprime 8y ago
Or you could think of this: the A330 has fewer total fatalities than the MAX, despite being in service for over 25 years instead of under 2 years.

SmellyGeekBoy 8y ago

> Think of this every time you fly Airbus. Why? They're not falling out of the sky so the system obviously works. Stop being a fanboy.

foldr 8y ago

>Now they are stuck because they feel they can’t change and have some planes that (dangerously) average the inputs, and some that are physically linked. This is a really weird way to construe the situation. The accident report doesn't conclude that the handling of dual inputs was a factor, and it's clear from the transcripts that it wasn't. Airbus has no reason to change this. Merely linking sidesticks would be pointless in any case, since sidesticks don't have an identifiable position (but are used with brief movements away from center). It's hardly any easier for a pilot to passively observe the movements of his own sidestick than it is just to look over at the other pilot's stick.

neuronic 8y ago
The commenter appears to have a vested interest in making Airbus look bad, otherwise the comment cannot be logically understood. Is there a case where the averaging of inputs has been proved catastrophic?
- notfromhere 8y ago
  Air France 447
  - foldr 8y ago
    Not according to the official accident report. This is a meme spread by an article in Popular Mechanics that came out long before the official report.

deleted 8y ago

[deleted]

benhurmarcel 8y ago

> Airbus negligently averages these inputs. On an Airbus, in case of dual input the pilots get a voice alarm and a warning lights up right in front of them. Also the stick has a switch to take priority, in case the other pilot continues to give dual input.

jandrese 8y ago
Did AF447 not have this warning? One of the contributing factors to the crash was the copilot continuing to pull back on the stick even as the pilot attempted to push the nose down to get out of the stall.
- livatlantis 8y ago
  I answered further up but: yes, it did. The DUAL INPUT alarms were audible in the cockpit voice recording. However, unbeknowst to the captain, the co-pilot used priority takeover on his side. (This was always visible on the panel + there was an audible "Priority right" warning around the end) Source: https://www.vanityfair.fr/actualites/articles/vol-af-447-rio-paris-reconstitution-des-minutes-qui-ont-precede-le-crash/23618 https://www.vanityfair.fr/actualites/articles/vol-af-447-rio...
  - foldr 8y ago
    I'm not sure where you're getting the "unbeknownst" from. In the cockpit voice recorder transcripts attached to the official accident reports, it seems that the pilots were aware of who had control at any given point in time.
    - jandrese 8y ago
      I remember right before the impact with the water the captain finally realizing why his controls aren't doing anything and asking the co-pilot to finally let go of his stick. IIRC they never did throttle up however. Ultimately the co-pilot got tunnel vision and thought for some reason they were in an overspeed condition for most of the incident and failed to communicate that effectively with the rest of the crew. He made a couple of comments about it, but nobody else realized that he was attempting to correct for an overspeed condition in the middle of a dead stall, even when the airspeed indicator came back it seemed wrong to him because he thought they were going too fast.

cjbprime 8y ago

Or you could think of this: the A330 has fewer total fatalities than the MAX, despite being in service for over 25 years instead of under 2 years.