This argument was made for each of those now-obsolete roles. I'd want to see data before concluding there is a benefit to a second person on checklists. In reality, that advantage would only manifest if the captain is inexperienced, self-check systems have failed and the radio/remote ops have failed.
> Even if there is a relief pilot onboard they might be sleeping and unable to make it to the cockpit fast enough to help
Can you name a crash which occured because the FO was in the bathroom?
Germanwings 9525. Can’t discount human factors, especially in an industry where human factors are very frequently the root cause of incidents.
More importantly I can name any number of flights where two pilots became task saturated and flew a plane into the ground. Or flights where a single pilot used bad CRM to force the other pilot to do something stupid, even though they both knew it was stupid. Both of those would be more common without a second pilot, general aviation is proof of that.
Not a great argument for a second pilot unless the second pilot never goes to the bathroom. The human factors involved in Germanwings 9525 didn't randomly occur during the flight, they specifically occured while the co-pilot was in the bathroom.
> Both of those would be more common without a second pilot, general aviation is proof of that
Between the reliability of piston engines versus jets to the experience of someone with a PPL versus ATP, this comparison includes far more variables than number of pilots.
> I can name any number of flights where two pilots became task saturated and flew a plane into the ground
I can do that for any value of N. The question is what the ratio is between N = 1 and N = 2, and how that has changed with evolving automation.
> where a single pilot used bad CRM to force the other pilot to do something stupid, even though they both knew it was stupid
Not really an argument for a second pilot either...
I'm not saying we have the evidence to say a single pilot is sufficient. I'm arguing that nothing you've brought up shows it's critical. That said, I'm sure we'll wait until another aviation authority pioneers the way. American aviation ceded the first-mover position decades ago.
While that's true, it is a good argument for a third pilot.
To stop one crash in decades amidst hundreds of thousands of flights per day [1]? If you place that high of a value on a human life, there are better optimisations to do first at much lower cost.
I'm just pointing out that while my parent was correct that the argument failed as a justification for two pilots, it doesn't fail for any other number. It's similar to the proof that all horses are the same color.
It doesn't fail as much as not work. One can always come up with hypotheticals justifying more redundancy. Whether that's worth the tradeoff requires actually looking at the facts.
One of the changes from that incident is that there is always a second person in the cockpit. If a pilot needs to leave the cockpit for some reason, a second crew member must come in and ensure that the pilot flying doesn’t lock the other pilot out.
As to the rest of the argument: the whole point is that two pilots is safer than one by a very large margin. We eliminated engineers, radio operators and navigators because we know have systems that do that better than a human. We do not yet have systems that do the job of pilot as well as a human. Commercial autolanding has existed since the 1960s but there are still situations where the pilot has to land the plane. We aren’t there yet.
I don't think that's a strong argument. The only time a pilot goes to the bathroom is during the most boring portion of the flight when everything is going exactly as expected. Planes so rarely have excitement occur at that phase of flight that the odds are really low of it happening at the exact moment one of the pilots is using the head.
Planes don't have something go wrong to the point of running checklists in an expected way.
This is an argument for offloading checklists to an automated system. Not having more pilots to run more checklists.