The WAC are open only to unlimited level pilots flying single engine propeller driven aircraft, whilst the Advanced championships are restricted generally to advanced pilots and there is also a list of eligible aircraft. These championships are organised by the FAI, the Federation Aeronautique Internationale who are the world governing body for all air sports. Every two years or so the FAI also organise a 'Grand Prix of Air Sports', a sort of Aerial Olympics where all air sports are represented. The first of these was held in 1997 in Turkey - the next one in 2001will be held at Andalucia in Spain.
Few sports can be as physically and mentally demanding as competition aerobatics.
Sequences must be flown with split-second timing, precise speed and altitude control. Uncontrollable variables such as wind and temperature changes all have to be considered, requiring dexterity of mind and precise continuous planning on the pilot's part. A wrong turn, miscalculation of wind strength, or the slightest disorientation, could put the pilot out of the running. These latter will often be the most complex and difficult sets of figures flown during the competition. Sequences, comprising of up to fifteen figures, are adjudicated by a team of ten judges who will determine how each individual figure was executed.