[simias]

My software dev mind went elsewhere, I wonder if the long term solution might not be to make all these controls inputs to some computer ("fly-by-wire") that could be toggled to some failsafe mode if the physical devices jam somehow. You could decouple the pilot's inputs from the copilot for instance.

Of course as we've seen in the past that can introduce its own issues, for instance during the AF447 crash: https://en.wikipedia.org/wiki/Air_France_Flight_447

>Confused, Bonin exclaimed, "I don't have control of the airplane any more now", and two seconds later, "I don't have control of the airplane at all!" Robert responded to this by saying, "controls to the left", and took over control of the aircraft. He pushed his side-stick forward to lower the nose and recover from the stall; however, Bonin was still pulling his side-stick back. The inputs cancelled each other out and triggered an audible "dual input" warning.

[Mawr]

Ah, the dual input nonsense, see my other comment on just that: https://news.ycombinator.com/item?id=36729484.

Here's the dual-input moment of this crash: https://youtu.be/e5AGHEUxLME?t=2876

[nerdponx]

This story is horrifying, but it seems more like catastrophic pilot error than a problem with the fly by wire system.

[Mawr]

Unless the plan is to remove pilots altogether, this line of thinking is just going to lead to more incidents.

See https://news.ycombinator.com/item?id=36725176

[nerdponx]

That's not my point. I don't see where the fly by wire system specifically caused the problem in this particular accident. Maybe there was insufficient cockpit indication that the aircraft switched to alternate law? Maybe the pilots were insufficiently trained on the scenario of icing leading to auto pilot disengagement? Maybe the pitot tube design was problematic and led to excessive ice buildup? Maybe the pilot was having a psychological problem, or was too fatigued? Etc

[Mawr]

I see. Hypothetically, if there was no fly-by-wire system on that airplane, both pilots' input controls would be coupled to each other, eliminating the possibility of confusion as to what inputs are being made. In fact, all potential UX issues in regards to communicating the current input state to the pilots would be designed away: averaging the inputs, hiding the input of one pilot from the other, the possibility of dual input.

These aren't necessary characteristics of a fly-by-wire system, but its mere existence opens up the design space for them to exist.

Of course, I'm not arguing for removing the fly-by-wire system altogether ;)

However, whenever such fundamental paradigms are changed, great care must be taken to understand exactly how the new one differs from the old one.

In this case, the old direct input system afforded perfect communication of its state by default, but the new fly-by-wire system didn't. Care should have been taken to fully replicate the old behavior in the new system.