ok well what if u crash into each other ?
Combat planes are built to try to minimize the damage from a mid-air or other mishap. Some planes are more durable than others, but all of them are far more able to take a hit than your typical sport plane that you'd see at your field on a typical day.
ok cool sounds like it could be fun while challenging. is there a certain tyope of plane u have to use or scale?
It is a huge amount of fun, and it is very challenging. A lot of people who see combat for the first time assume that it's all luck or blindly flying through a crowd, hopeing for a cut. Of course it doesn't actually work that way.
If you looked at the RCCombat.com site or some of the other sources out there, then you already found out about the planes. In case you didn't, there are several differnet classes of RC Combat, with different rules about the airplane and engine.