The first calls are "Smoke on... Ready... Now..." They practice so much that they get into a rithym with that call. That way they are all on cue. The guy talking is the lead pilot. He's saying things like, "a little more pull..." and such to make sure that they don't loose each other in formation. Then, when the plane crashed, you hear one of the crewman on the ground, most likely the guy that acts as their ATC, telling them to knock it off. They all call out "Number ...whatever.... knocking off". You can hear them going in order. It's to make sure they all got the call.