A PC checklist usually consists of a task list that needs to be signed off by PCs in the company before you can be looked at by a PC board to determine if you're ready for a PC checkride. So really, the process is threefold: completing your PC checklist, getting looked at in a PC board, and completing a PC checkride (or sets of checkrides). It will take awhile to complete your PC checklist, but you should begin knocking it out piece by piece as soon as you can.
Remember that everyone will progress to PC at different times depending on a number of factors. Maturity and judgement are going to be looked at by all the PCs that you fly with and will be big factors in determining if you are ready to be a PC. I have seen many people think that they should be a PC because they have a certain number of hours. That is NOT how it works (or at least not how I think it should work). There are 800-1000 hour pilots that shouldn't be PCs, and there are 500 hour pilots that should be PCs. The attitude that PC status should be given to you and not earned is (in my opinion) in and of itself a sign that you aren't ready to be a PC.
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The PC checkride will be much different than any other checkride that you've had so far. You will be functioning as the PC (so make sure you've taken the time and asked other PCs if you can act as PC while you're out doing missions and training.) The IP/SP that is giving you the checkride will be acting as a fresh PI. You will be given a mission and constraints and you need to complete the mission and make PC level decisions throughout the flight. You will probably have an in depth academic evaluation as well. Expect that you will have some changes come up throughout the flight that you weren't briefed on. This is part of the process. Don't let the "PI" do anything stupid. Remember, you are the PC for this flight. Take charge and make decisions. It will probably be a very stressful flight.
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If you pass your PC checkride, you will be made a PC for the company. At this point, you might feel like "I've made it", but again, don't get complacent. Many PCs get that invincible attitude that leads to accidents. However, enjoy your time as a line pilot PC. It is very enjoyable. You'll get to build your skill set and you'll probably actually learn a ton as a PC. I know I did. Remember though, that you have more to look forward to in your a career....like choosing a track. I'll talk about that in my next post.