RULES:

 

Judging

Flights are judged by more than one person, they are judged by a team of judges with at least one assistant to record the scores. These judges grade the execution of each individual manoeuvre of the sequence, as well as how well the manoeuvre was positioned within the box. The manoeuvres are graded on such factors as precision of the lines and angles, symmetry of manoeuvre and other factors. Anyone can become an aerobatics judge and the most simplest being a boundary judges that determine when a competitor leaves the lines that make up the box, "out" is called in to the Chief Judge by radio and recorded if the competitor leaves the box. Each judge has a copy of the figures the pilot will fly. On these sheets the figures are graphically represented by symbols which all of the pilots and judges must know.

 

Scoring

The judges grade each manoeuvre on a scale of 0 to 10. The K factor and grade are multiplied to derive the points for that figure. Judging aerobatics incorporates many of the characteristics of judging figure skating, gymnastics and diving.

 

The Box

Sequences are flown in an aerobatic zone, commonly called the "Box", over an airport. This box is a cube of air 1,000 meters square above the ground. All aerobatic competition flying is done inside the box. The bottom of the box depends of the level of competency of the individual pilot but it is set at 100 meters above the ground for Unlimited or highest standard competition. Any pilot who flies outside the box is penalised. Beginners have to fly higher whilst the unlimited pilot is trained to fly at the bottom of the box. There are 5 levels in aerobatics Basic, Sportsman, Intermediate, Advanced and Unlimited.

Lower limits:

Basic-1500 feet above the ground.

Sportsman-1500 feet above the ground.

Intermediate-1200 feet above the ground.

Advanced-800 feet above the ground.

Unlimited-328 feet above the ground.

 

Ref: http://www.aerobatics.nl/aerobatics.htm