Even if one person can fly the aircraft, it’s reasonable to ask some questions: Is this what we want? When we say “can be”, do we mean in routine conditions or in extreme conditions? We might know the names of Chesley Sullenberger or Al Haynes, but would they have become “heroes” if not for Jeffrey Skiles or for William Record and Dudley Dvorak? The pilots in both cases were doubtless assisted by checklists, but I’ll contend that it wasn’t the checklist that controlled the aircrat and saved the lives. The checklists tend not to cover situations like “all control surfaces unavailable”.

Here’s a comment from James Bach, who has insight from the perspective of an actual pilot. I’m hoping that James’s brother Rob (a commercial airline pilot) will weigh in, too. Meanwhile, James says,

“To use a checklist responsibly is not to be dominated by it. That distinction is absolutely critical to safe flying.

“I come from a flying family. Yesterday I was checking the bolts on a new Quicksilver on floats that my father and his mechanic are assembling. Each of us did some assembly on the various struts, fitting and bolting the parts to the frame (loosley). Then the greybearded mechanic torqued and safetied each bolt, followed by Dad and I who made separate passes to inspect his work. We trust in the skill of the mechanic to do the job right, but we check his work all the same, as he cheerfully dared us to find fault with it.

“The aircraft comes with a thick manual, to which we occasionally referred. We discovered at least one puzzling contradiction (the manual says the engine won’t burn avgas, whereas the engine has a placard warning against any other fuel exept avgas) and the mechanic identified a design flaw in the landing gear locking mechanism that caused him to suggest a redesign to improve safety (metal fatigue was occuring in the connection between the bowden cable and the gear locking plate, and he suggested installing a clevis joint to alleviate the stress.)

“As with flying itself (I’m a perpetual student pilot since forever), aircraft maintenance is exacting work, but you will find in all cases it revolves around skill and judgment, with manuals, regulations, and checklists playing a critical but supporting role.

“There’s an important distinction between ‘serving the purpose of quality assurance’ as one skilled in the work at hand, or as an unskilled lackey who is there only because he can read a checklist.”

In some situations it is better to document or perhaps automate the task. For instance, when performing the same set of tasks that would be possible to script in one way or the other.

Many organizations claim to do this, just as many claim to keep their documentation current, but few actually do what they claim.

I don’t think you picked a very good analogy.

Even though the pilot may get pretty busy, all commercial aircraft can be safely flown by a single person. The most important function that the copilot serves is quality assurance.

And regardless of the number of pilots, you will always find checklists actively used in all aircraft.