Aerobatic sport is exciting, including such features as acrobatic flying on piston and jet aeroplanes, formation flying, aero rallies, air racing, landing accuracy competitions, and setting a variety of records. Aerobatics competition programmes are enhanced on a regular basis. There are World and European Championships, Cup and International Competitions staged. Aero rally and acrobatic flying on powered aeroplanes were included in the programme of the World Air Games, which took place in Turkey in 1997 and in Spain in 2001.
Acrobatic flying is the most spectacular and challenging kind of aerial sport as it involves putting the aircraft and the pilot to the limit. The programme for the World and European Championships includes several sequences of aerobatic figures, and the execution of various manoeuvres is evaluated by the judges to within one degree. Each aerobatic figure is a combination of various lines (horizontal, vertical and angled lines and loop sections in normal and inverted flight) and rotations (spins, controlled, fixed, and inside and outside rolls). For example, a rolling turn is a 360° turn in the horizontal plane (turn) with simultaneous rolling of the aircraft (one roll is 360°); there may be two to four rolls; they must be performed at constant roll rate and constant turn rate. Flick (snap) rolls are gyroscopic rotations performed in a stall at up to G ±10. Each aerobatic figure has a numeric difficulty factor. The judge's mark for a figure is multiplied by the difficulty factor and the score for the sequence is arrived at by way of an involved mathematical procedure using statistical techniques to prevent a biased assessment. Certain sequences are practised by pilots for months on end (Known and Freestyle), others (Unknown) are put together directly at the event based on the pilot's own "homework", with each team contributing one figure. Unknowns are the most challenging sequences for the pilot since they are announced to the participants just hours before the flight and can only be practised by the pilot on the ground "waving his arms around" and must be presented to the judges as soon as he gets into the aerobatic box, without any second attempts granted. The pilot with the highest overall score will become the absolute champion (winner).
All the sequences must be flown by the pilots in a limited-space aerobatic box. The box is marked out on the ground using strip panels as a 1,000m-side square, with a minimum allowable flying height set at 100 to 1,000m. Any infringement of the box boundaries entails penalties to be subtracted from the pilot's score.
The history of Russian sports aviation