[icebraining]

Somebody has to be responsible.

Nope. You don't have to have any single person trusted - that's the whole point of having two pilots. This is just extending that basic systems architecture notion (having no SPOF) where it's lacking.

[acqq]

No, the point of two pilots is the possibility for them to chose who is actually controlling the plane at some given moment, optimizing their performance, not that you don't trust one of them. The current systems trust both.

[dingaling]

And until the early 1980s we had the Flight Engineer to keep an eye on the two pilots. They drove, he managed the aircraft and made sure they didn't bend it.

It was not unusual for the Flight Engineer to be senior to the drivers.

But the airline accountants highlighted the personnel cost of Flight Engineers and eliminated them, without ever considering the operational cost savings they provided. Even in mundane matters like resolving departure issues without having to wait for the on-call engineer.

"How long to fix it, eng?" became "What's wrong with it now? Back to the gate."

[shiggerino]

The same thing happened in shipping, getting rid of the radio officers, which unlike aviation is also compounded by very lax regulation.

Modern ships are filled with fancy electronics, and it's usually poorly designed with broken software, that few know fully how to operate and nobody knows how to fix. This problem is only going to increase as they rely more and more on automation, and it's not going to stop until there is an accident severe enough to prompt aviation-style regulation and safety methodology.

[jacquesm]

It's nothing to do with trust but everything to do with redundancy.

[icebraining]

Redundancy is a response to a lack of trust in the reliability of a component.

[jacquesm]

Yes, but that reliability is not the one that we normally think of when we use the regular language word 'trust'.

'I trust the pilot' does not imply that I think that the pilot will have a long and healthy life. There are two pilots because one might have a medical emergency, emphatically not because one might go mad.

In fact, if one does go mad, even with the other one present, there are plenty of ways in which the 'mad' one can run the plane into the ground if they so choose to.

So the 'two pilots in the cockpit' kind of redundancy is to protect against the cases of individual pilots becoming incapacitated.

Of course having another pilot in the cockpit will probably somewhat reduce the chances of a pilot with a mental issue being able to inflict damage simply because he'd have to either get physical with the other pilot or at a minimum would have to look them in the eye. But that's nowhere near what is required to stop a plane from crashing if one of the pilots decides to do it.

Which is one reason why it doesn't really matter if a flight attendant is present in the cockpit instead of another pilot. That's mostly a psychological issue, not a practical one.