Aircombat is held in several forms.
ACES (1/12 scale) aircombat uses stand-off scale warbirds, where 6 to 8 pilots take to the air at the same time.
fight time is 7 minutes. This includes running towards your plane, starting the engine and getting airborne.
Points are awarded for streamer cuts and flight time (airborne) Crossing a safety (pilot) line deducts 100 points; crossing that line twice on a day means disgrace for the day's contest.
For all ACES rules, look at www.aircombat.nl .
USA has different sets of rules, though they too fly 1/12 scale in some events.