A few blog posts back, I tried to emphasize the relative importance of skilled people over documentation by remarking that commercial airlines “tend to have a captain and a first officer in the cockpit, rather than a pilot and a book on how to fly an aircraft”. “Tend to” was intended to understate the case; as Rob remarks below, you’ll see single pilots only on very small planes (like the seaplane that I took once from Nanaimo to Vancouver—one pilot and six passengers).
gmcrews commented “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.” gmcrews also said, “And regardless of the number of pilots, you will always find checklists actively used in all aircraft.” That’s true, but my point was that the skilled humans, rather than the checklist, are at the centre of the operation.
I asked Rob Bach, brother of James and Jon and a pilot for a major airline, to respond to that, and he did, although some enthusiastic spam filter appears to have stopped the first attempt. Rob says:
ALL airlines have more than one pilot if there are more than 10 or so passenger seats on the plane. The reason is not for quality assurance, I assure you.
As a pilot for 33 years, a commercial pilot for 22 years, an airline check pilot for a few of all of those years, I can tell you exactly why there are two to FOUR pilots on any given commercial flight.
The Captains are there to keep the First Officers from killing themselves. The First Officers are there to keep the Captains from killing EVERYBODY.
No, seriously:
People make mistakes. Two people make TWICE as many mistakes as a single person, but the likelihood that those mistakes are identical in nature and time are reduced by the way we coordinate our skill sets.
The FO is not there for assurance, but to command the flight if need be, countermand the Captain if need be, learn from the Captain if possible, fly the plane every other trip leg (run the radio gear the other legs), share pre and postflight duties. FLY the plane during emergencies (unless the Cap elects to do so… but it is rare the Cap doesn’t run the checklist in an emergency), and on and on.
It physically takes two people…like hanging sheetrock.
The cockpit, the plane, the atmosphere, and the air traffic environment are amazingly complicated places where the room for error is quite small. It takes TWO brains working all sides of a flight from minute to minute to make all the magic happen.
Having flown single-pilot in heavy weather into a busy airport, I can state that I was in over my head and don’t relish the thought of going back to that space/time. There’s just too much data coming and going through your brain. Like Tetris in some insane hyper-mode where DEATH is the cost of losing the game.
OK…that was a little dramatic.
Two (or three to Europe and four to India) pilots are used to help ease mental and physical fatigue. Imagine performing at peak mental level at a reduced cabin pressure/oxygen level, in a very dry environment, being irradiated by the instrument panel AND the sun, in an uncomfortable chair where you can’t stretch your legs easily, where you can’t use the bathroom ‘CAUSE HEY, WHO’S FLYING THE PLANE! for a 15 hour day back and forth between timezones, sleeping in unfamiliar surroundings, away from family (but still dealing with all the family issues one needs to deal with) , missing graduations, births, weddings, ball games with your kids, for YEARS:
Don’t you think the reason we have at least two highly-trained professionals is something more than just quality assurance?
Thanks, Rob!
Hi Michael,
At the risk of “trying to control a debate by controlling the meaning of the terms,” (not a thing I would want to do) let me comment on my use of the term “quality assurance”.
Quality assurance refers to those actions taken to provide confidence that (in this case) the commercial airline flight will “satisfy customer requirements.” The key word in the definition is “confidence.”
Neither I nor the FAA would currently be “confident” in the safety of a completely automated commercial aircraft. Nor would a single pilot be enough. However, with two pilots we do have the required subjective(!) confidence. Why? Fundamentally, for exactly the reason that Rob Bach stated: “People make mistakes.” All the other work-load/fatigue/size issues, while of practical importance, are secondary to this fundamental truth.
Risk is probability multiplied by consequence. The consequences of commercial airline pilot mistakes are pretty high. The copilot is there to reduce the probability of a mistake to a level that gives us the required confidence against the risk. Automate or apply technology to all the work-load/fatigue/size/etc issues you care to and you still get two pilots in the plane in order to provide the required confidence against mistakes.
And checklists are the same thing. Confidence against errors. That is, we are confident they help prevent overlooking something — is the fuel switch set to an empty tank?
So yes, while not disagreeing with anything Rob said, I do think it’s basically a quality assurance issue.