I have not done this in a while but in the late 80 early 90 two friends and I were quite good at it. Now we mainly tried to fly close on the runway and once in the formation would do split-S's at the end of the box. We started by dividing the sky over the runway in to nine lanes labeled 1, 2, 3 across the runway and wimpy, low, and grass stained (High, medium, and Low respectively). After a turn the lead guy would call which lain he was going to take, then the second guy would call his lane. This was all done while pulling out of the Split-S.

We all had Ultra Sport 60's we never had a mid air, I still have mine. We would start with one guy low passing the runway and the other two would join in and we would adjust our position in relationship to each other in the split-S by shortening up the vertical pull. We were always at full throttle, the planes were all within 5mph of the others speed. The only problem we had was one of the pilots was relatively new to R/C three years experience when we started and he did not understand how to lift vector or use his rudder. It did not take long for him to figure it out how to stop his plane from crossing lanes.

Loads of fun, good luck!

Joe