Alright kiddo, so you know how when you want to do something, you might need permission from a grown-up or a teacher, right? Well, airplanes are kind of like that too.
Before an airplane can fly, it needs permission from the government of the country it's in, and sometimes from other countries it will be flying over. This is called a flight permit.
The government wants to make sure that the airplane is safe and meets all the rules and regulations for flying. They also want to make sure that the people flying the airplane know what they're doing and have the right training and experience.
So, the airline or the pilot has to fill out a lot of paperwork and provide information about things like the airplane's weight, how many people will be on board, the route it will take, and what kind of equipment it has on board.
Then, the government looks at all that information and decides if it's okay for the airplane to fly. This can take a little while, because the government wants to be really careful and make sure everything is just right.
Once the government decides it's okay, they give the airplane a flight permit. This is like a permission slip that says the airplane is allowed to take off and fly.
So now the airplane can fly safely and legally, just like you can go on a field trip when you have a permission slip from your teacher. Pretty cool, huh?