Although the following notes are gleaned from US AMA competitions, they are very similar to BMFA events in the UK.
The order of flight is completely random. Although there is some room for manoeuvre, you must remember a lot depends on the radio frequencies of the individual RC helicopters. Evidently, the more 2.5GHz transmitters there are on the field, the easier it is to vary the order. It is a good idea to have a few spare crystals with you, in case your designated frequency is a popular one!
For two day events, there are generally 5 competition rounds. Small local contests may have manual scoring, but big public events often use a computerised system.
Most clubs for RC electric helicopters are BMFA sanctioned. Therefore, BMFA membership and insurance are required, as are proof you hold the BMFA Certificate B (for flying RC helicopters at public events).
Electric helicopters are flown one at a time from the flight box. There can of course, be more than one flight box in operation at the same time (and generally are, provided there are enough judges), but the Radio Control Helicopters must be on different frequencies (if applicable).
It is usually expected that you have a caller or spotter. This person will call the manoeuvres, make sure you don’t collide with other RC helicopters, and make sure you don’t break the rules (for instance, by stepping outside the box). This allows both you and the judges to concentrate on the 3D action. Your spotter should know that calling isn’t just for the benefit of the pilot. They also have to call the beginning and end of each manoeuvre to the judges.
If you don’t have a spotter, don’t worry. There’s always a willing volunteer – just remember to have a calling sheet, so they know what to do.