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>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.

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?

Air France 447

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.

> 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.

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.

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...

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.

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.

The captain wasn't at the controls.

I'm not sure what you mean by "throttle up". They were at full TOGA thrust.

The copilot actually suggested to use the airbrakes at one point.

  Neither Bonin nor Robert, nor the third crew member (Marc
  Dubois, the captain) who entered the cockpit 90 seconds
  into the episode, recognized that the aircraft had stalled
  despite multiple cues. In the confusion, Bonin 
  misinterpreted the situation as meaning that the plane was 
  flying too fast and actually reduced the thrust and moved 
  to apply the speedbrakes – the opposite of what was 
  required to recover from the stall. Robert overruled him 
  and attempted to take control, but Bonin continued to try 
  and fly the plane. He and Robert made simultaneous and 
  contradictory inputs, without realizing that they were 
  doing so. By the time the crew worked out what was going 
  on, there was insufficient altitude left to recover, and 
  AF447 crashed into the ocean, with the loss of all 228 
  passengers and crew.


  But I've had the stick back the whole time!

  At last, Bonin tells the others the crucial fact whose 
  import he has so grievously failed to understand himself.

I know what the Popular Mechanics article says, but I cannot find any confirmation of the key points in the official accident report, which I take to be much more reliable.

Here's the official report: https://www.bea.aero/uploads/tx_elyextendttnews/annexe.01_04...

Page 28: The right-seat co-pilot Bonin says "j’ai l’impression qu’on a une vitesse de fou non qu’est-ce que vous en pensez ? "(I feel like we're speeding like crazy, what do you think?")

Page 31: Same co-pilot "mais je suis à fond à cabrer depuis tout à l’heure " (But I've pulling back completely for a while), and this while the cockpit is screaming "Dual Input" (so this means that the other pilot was inputting as well, thus "unbeknownst" in my original comment).

Same page, right after, the captain says, "non non non ne remonte plus là" (No, no, no, don't pull back any further".

If you read the entire transcript, it's clear that there was persistent confusion as to who was in control, despite the dual-input warnings. AF447 is widely considered to be a failure in CRM, and a failure to recognize that they were in an aerodynamic stall (again, despite the warnings).

They didn't trust the plane with the information it was providing, which is probably why they ignored these warnings.

>Page 31: Same co-pilot "mais je suis à fond à cabrer depuis tout à l’heure " (But I've pulling back completely for a while), and this while the cockpit is screaming "Dual Input" (so this means that the other pilot was inputting as well, thus "unbeknownst" in my original comment).

Perhaps you didn't notice this, but immediately after the point in the transcript you refer to, there's an exchange between the pilots where they establish who's in control (see "vas-y tu as les commandes" at 2 h 13 min 46,0). There is no way to be sure, but it seems probable that this exchange was prompted by the dual input warnings.

>They didn't trust the plane with the information it was providing, which is probably why they ignored these warnings.

There is no indication that they ignored the dual input warnings.

Linking the control sticks doesn't magically resolve problems caused by a breakdown in cockpit discipline. If both pilots are going for the controls at the same time, you're going to have problems. The warning system seems to have done its job, insofar as it prompted the pilots to figure out who was in control.

Oh, I don't think I alluded to linking the control sticks... perhaps you intended to respond to another comment?

As for the dual input thing, there are 6 instances of the the warning. We can't really know what the pilots were thinking, but I believe page 31, from when Bonin says, "je suis à fond à..."... and then Robert à "attends moi j’ai des j’ai des commandes moi hein" a little later, "alors donne moi les commandes à moi les commandes", and 4 warnings Dual Input between them (in the space of about a minute and a half)...

I think it's fair to say that it wasn't super clear who was in control.

I'll make no comments about which system is better since I have no direct experience of flying in such environments (have only piloted small aircraft with mirrored controls, but with clear "Commande à droite/gauche" to establish PF, with my instructor). But à priori, I would imagine both systems work fine if used well.

You referenced an article that blamed the crash on the fact that the control sticks weren't linked.

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.

> 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.