There are almost as many answers to that question as there are pilots. Sometimes it comes down to the need to get turbine pilot-in-command (PIC) time at a regional airline to become more competitive for a position at a major airline. Sometimes it comes down to being tired of flying with the same people, or on the same routes, all the time. Sometimes it just comes down to the pay raise.
Upgrading at any airline is a big decision. The training process alone, especially if you’re not just switching seats, but switching airplanes, can be pretty intense. As a first officer (FO), you are expected to have a pretty good working knowledge of the books, specifically the one that spells out all the rules for operating at the airline as a pilot. Usually called the flight operations manual or operations manual, or something similar, this is the nitty-gritty of how to run the flight operations department. It covers everything from hazardous materials to how to choose an alternate airport or determining when it is appropriate to remove a passenger or even a crewmember. This is not to be confused with the flight manual for the actual airplane, which strictly deals with the nuts and bolts of how to operate for a specific fleet. For the FO, this operations manual still is an important resource, and you can expect to be grilled on certain sections during checkrides, line checks, and other evaluations.
But for a captain, the requirement goes from having a working knowledge to having an almost intimate familiarity. You need to have a much higher degree of recall, and when you are asked to find something, you’re expected to do so in seconds, not tens of seconds or minutes. Most captains will tell you that most of the study and prep for the position comes from diving into the weeds of the operations manual because of the increase in responsibilities and duties. Reports dealing with passenger issues, weather encounters, declaring an emergency, and more all fall on the captain, and these reports have stringent timelines associated with them.
Aat some point, every FO feels like they could do better than, or as well as, the folks they’re flying with every day. And eventually, that becomes more true than not. But there’s more to it. A captain often must balance the need for the airline to make money with the need to maximize safety. When a situation is black and white, it’s easy. It’s when the gray area begins to grow that it gets hard. Writing up a broken piece of equipment, refusing to take off because of a too-close-to-cut-it holdover time after deicing, or refusing an airplane for some reason are not always easy decisions, and the domino effect can be significant. You can’t make these decisions cavalierly.
At a minimum, you should have some experience operating in several seasons each of thunderstorms and winter operations. You should have some experience at as many challenging or special qualification airports as possible. And, of course, you should know the books like the back of your hand. Some pilots take years to feel up to the responsibility, and others ultimately decide that life as an FO is simply too good to give up. But for most of us, being a captain is a major accomplishment, and one we greatly look forward to.
The best way to say it is that if all else is equal, and one need doesn’t override the others, then it’s a matter of doing it when it feels right to do it. You should feel confident, but not cocky, humble but not scared, and modest but not unsure. Putting on that fourth stripe is a big step and a huge thrill. Make sure that you are ready when you put in the bid, and you’ll be able to fully enjoy the job and the perks.