There are 2 routes for male military service in Turkey:
You have either graduated from high school, or you have a minimum of 4-year bachelor's degree.
For the first scenario:
When you graduate from high school and you are 21 years of age, you receive a letter from the army, saying that you need to come and register. So, you go to the recruitment office and register for the next recruitment term. At the recruitment office, they check you for general health and other things like tattoos etc. If you have an illness that may prohibit you from recruitment, you need to state it there. In the end, if you are eligible, they register you to the next available term. When your term comes, you go and surrender to your regiment and start your military service. You can be assigned as anything. They may assign you to Land, Sea or Air. I don't think that you can be a pilot though. But you can still operate as a low ranking soldier.
After the amateur training, which takes about a month and a half, you are transferred to your professional service regiment. As you are a high school graduate, your military service will be 12 months. It is called the long-term plan. When you complete your service, you're given a document that you've completed your service and free to live your life as you please.
On the second scenario:
When you graduate from university, which can be all the way up to 29 years of age, you receive a letter from the army. If you are over 29, you will still receive a letter from the army and required to surrender. Then, it is pretty much the same as the other scenario. However, your military service is shorter. You are either assigned as a private for a 6-month service or you are assigned as a reserve officer for 1 year I think. (I'm not too sure about this).
Just as the other scenario, you receive your discharge papers and can live your life as you please.
If you don't go and register, you can be arrested for skipping military service. Military Police used to show up at your door in the early day, but since 2008-2009, they've stopped doing that. If you get stopped at a police checkpoint, you may be required to go to the police station to sign a document that says you will be surrendering in X days. But most people don't. There is a tax penalty for that tho'.
Note: Most people don't actually wait for the army's letter. They just go to the recruitment centre to get it over with. However, currently there are millions of people in Turkey who just don't want to do the military service and they just don't go to the centre at all. They can't be punished or arrested or jailed. They can only receive a fine which multiplies in time.
