figures

FIGURES

The figures are graded on factors like precision of the lines and angles, symmetry of figures and other factors spelled out in the catalogue used by all pilots. Each judge has a copy of the figures the pilot will fly. On these sheets the figures are graphically represented by symbols. The system of graphically depicting the figures was devised by Jose L. Aresti of Spain for the use in World Aerobatic Championships (WAC). It has been successfully used for many years.
In addition to the graphical symbol, each figure is assigned a difficulty coefficient or "K-factor" based on the difficulty involved in performing the figure. The K-factor and the grades given by the judges are multiplied to derive the points for that figure. A computer then adjusts the totals to account for bias.
 There may also be a Classic class for airplanes without inverted fuel and oil systems. The sequences flown are very similar to those flown in the Sportsman category.  Within each class, each pilot flies several programmes. They are:
 Known:  Determined each year by the FAI, which is flown by all contestants at all contests all year long.
Free: In this program, each pilot is given the opportunity to demonstrate his personal flying skills, creative talent and his aircraft performance by designing his own sequence.
Unknown:  This program is made known to the contestants only 24 hours before the competition and the figures are chosen by the contest chief judge. The pilots must fly it without prior practice. (For classes Intermediate and above.)
4-minute Free: Only the top unlimited pilots might be invited to fly this final program. It is for this program that new figures are sometimes flown as pilots strive to display their creativity and superior skills as performers.