ALL CADETS have 3 each, 3 week, summer sessions. 1 will be 3 weeks AT the academy doing work/details type stuff. Another 3 week session for the upper classmen is usually OPS. "They go to another air force base somewhere in the world". For those going from C4C to C3C (First real summer there), they generally have you doing survival type training instead of going to another base for ops. But this training changes all the time, so it's hard to say. The 3rd session is vacation.
My son, in the summer after his C4C year, spent 3 weeks of training and 3 weeks of work at the academy. (During this time however, he was also allowed to do Gliders. Some others did parachuting). Then, he had 3 weeks of vacation. Even though he was an IC football player, he still has 3 sessions of 3 weeks each. Matter of fact, that is one of the hardest things for academy football. They don't get to have ALL of their players back together until the day school starts. (First thursday in august).
You son will not be getting out of any of the 3 sessions because he's an IC. I assume he's a C4C because if he was a C3C or above, he'd already know the answer, and you wouldn't be asking it. He will have 3 sessions in the summer. Vacation, training, details. If he still has questions, have him ask upper classmen on the team. Now, there are definitely some restrictions for athletes. e.g. coach wouldn't let his football players do jump until later. Doesn't want to take a chance of messed up legs. "Then again, they discouraged skiing and snowboarding too". The only people who get out of part/all of a session, is their Vacation session. Some will voluntarily give up their vacation to do an immersion program where they go to another country. This year, a cadet/friend from our town did 3 weeks in his ops at a base over seas. Then, he did another 3 weeks in Japan. He had to give up his vacation session to get this. Good luck.