There are two different monthly schedules that flight attendants and pilots can have. One is a RESERVE and one is called having a LINE. Think of reserve as being on call similar to nurses or firefighters. When you're first starting off you'll be a reserve flight attendant, reserve flight attendants must have their phone on them and wait for crew scheduling to call. Depending on the airport you’re based at you’ll have 2-3 hours after scheduling calls you to make it to the airport to sign in for your assigned trip. While on reserve you have NO idea where you’re going until you receive that phone call, which can be stressful but also fun especially when you get a great trip. Having a line is much different. A “line” means that you have and you know your monthly schedule of trips ahead of time. The month prior you are able to “bid” for the specific trips you’d like to work, layovers, days off, etc. The type of schedule you hold depends on your seniority with the airline.
When you and friend have enough senoirty you'll have the option to drop your trips on your airlines electronic trade board. The electronic trade board is where flight attendants can go to drop trips, trade trips, and pick trips up. For example, if I have a few days off and want extra hours, you'll be able to go to the trade board and pick up a trip you would like to fly. If you cannot get another flight attendant to pick up the trip you’re attempting to drop then you do still have to work it. On the trade board, you also have the option to trade your trip with another flight attendant’s trip only if they approve of it though. Having the option to drop and trade your trips helps tremendously especially if something comes up last minute and you are not able to work your original trip.
Good luck to you and your friend Carys.
John recommends the following next steps:
I have a friend that has been working as a flight attendant for a handful of years, and while she can't match her schedule directly with her best friend that also works for the airline, with seniority in her position she is able to swap shifts with coworkers to better align her schedule with her friend's. I'm not sure how it works for every airline, but just thought I would provide this example.
Best of luck!