When I speak of a co-worker, or a co-driver, I'm speaking of a mutual relationship and status (that's simply how the prefix co works in normal English) and I'm pretty sure it's what most people mean too.

When people speak about co-pilots on the other hand, it seems they might mean one of several things:

  • They are speaking of two pilots who happen to be working as part of the same crew, who are therefore co-pilots (which seems the most correct usage).
  • They mean a pilot who isn't the captain.
  • They mean the pilot monitoring rather than the pilot flying.
  • They think the aircraft has a pilot, and a kind of assistant pilot of lesser abilities known as a co-pilot.

(This last seems to be strangely prevalent, as if people imagine an airliner might be crewed by a fully-qualified professional and by some sort of assistant whose job is the aviation equivalent of holding the ladder, who looks forward to the day they'll be allowed to climb up it themselves.)

Weirdly, I have actually heard air crews use co-pilot in ambiguous ways, as though even they have given up trying to use the word with care; once I heard an announcement in one language that referred to the captain and the first officer, and then immediately afterwards in another to pilot and co-pilot.

Questions about co-pilot

It seems reasonable to say "my co-pilot" when speaking of a fellow crew member. However:

  • Does "the co-pilot" have any meaning (note the use of the definite article)?
  • Is co-pilot ever a rank?
  • Does the term appear in aviation regulations?
  • Is it used in crew management policies?
  • Is there indeed any standardised or formal use of it within the industry?
  • 3
    $\begingroup$ It probably depends on the country. In France Commandant/Copilot are used respectively for Captain/First Officer in the US. In my view this is clearer, as Commandant/Copilot are roles (pilot in command, and pilot), not rankings. $\endgroup$
    – mins
    Commented Sep 25, 2017 at 17:52
  • $\begingroup$ Hmm.. good question. I never thought of it that way. $\endgroup$
    – Trevor_G
    Commented Sep 25, 2017 at 18:00
  • $\begingroup$ I'm not sure that the FAA really recognizes a co-pilot, almost all regulations refer to the other crew member as the second-in-command, and even has a type rating as such. It mirrors the FAA's push to recognize the people in the cockpit as a team, not superior/subordinate. $\endgroup$
    – Ron Beyer
    Commented Sep 25, 2017 at 18:38
  • $\begingroup$ This seems almost like an English Language stackexchange question. $\endgroup$ Commented Sep 25, 2017 at 19:06
  • $\begingroup$ ........Jarvis? $\endgroup$
    – Wyrmwood
    Commented Sep 25, 2017 at 20:07

1 Answer 1


Does "the co-pilot" have any meaning?

Yes, Merriam-Webster says:

co- prefix

:having a usually lesser share in duty or responsibility: alternate: deputy • copilot



:a qualified pilot who assists or relieves the pilot but is not in command

while dictionary.com says:

variant of com- before a vowel, h, and gn: coadjutor; cohabit; cognate. The prefix co-, now productively forms new words from bases beginning with any sound ( co-conspirator; co-manage; coseismic), sometimes with the derived sense “auxiliary, subsidiary” ( coenzyme; copilot), and, in mathematics and astronomy, with the sense “complement” ( codeclination).

Both sources mention / hint at the co-pilot not being the highest in the command hierarchy.

Is co-pilot ever a rank?

Yes, the co-pilot is the second-in-command (SIC), right after the captain (even if the co-pilot has more hours than the captain—it does happen). If the captain ate the fish, the co-pilot becomes pilot-in-command (PIC).

Does the term appear in aviation regulations?

It's very rare (nowadays at least), usually second-in-command will be used. Here's a mention of co-pilot in an FAA advisory circular (not a regulation per se).

The Mentor Pilot. A mentor pilot is a professional aviator acting as a coach, co-pilot, teacher, and role model, sharing experience and expertise in the complex environments in which the EA500 will operate.

Is it used in crew management policies?

Not really. The terms used are pilot-not-flying (PNF) or pilot monitoring (PM), and pilot flying (PF). Because the captain and co-pilot can be either, they usually swap roles. The captain can be the PF on the out-bound leg, and PM on the return flight, for example. But the captain remains the PIC even when the co-pilot is the PF.

Is there indeed any standardised or formal use of it within the industry?

Popularity varies by location / culture / era. First officer (F/O) is also a valid alternative. Searching for jobs on Google, copilot returns ~9 million results, while F/O returns 30 million.

Using Google's Ngram Viewer could be skewed due to the F/O's usage in maritime environments.

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What does ICAO say? (My addition.)

It's not bothered really:

What is a multi-crew aeroplane?

It is an aeroplane that requires a flight crew of at least two pilots. One of them is the pilot-in-command (the captain) and the other is the co-pilot (or first officer).


  • 3
    $\begingroup$ Flight engineers are usually called second officer. $\endgroup$
    – TomMcW
    Commented Sep 25, 2017 at 22:40
  • 1
    $\begingroup$ You'll also see "second officer" used for a cruise relief pilot on a 3 man longhaul crew in some airlines $\endgroup$ Commented Sep 26, 2017 at 1:19
  • $\begingroup$ I'm not quite clear on the situation for the last part about "second officer." The only times I've seen that term used, it mean the flight engineer, a position which no longer exists on most modern aircraft. Are you referring to the "second officer" as someone who doesn't actually have a type rating for the aircraft yet? $\endgroup$
    – reirab
    Commented Sep 26, 2017 at 3:41
  • $\begingroup$ The first Merriam-Webster definitions for co you link to reflect equality and mutual status, and only later introduces lesser status - invoking the erroneous popular usage of co-pilot! Thanks for the ICAO usage contrasting Pilot in Command or Captain with Co-pilot or First officer, which aligns with its use as rank (and which is at variance with the FAA example of its use as a role). $\endgroup$ Commented Sep 26, 2017 at 6:39

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