Competition aerobatics
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Competition aerobatics is an airborn sport, in which judges rate the skill of pilots performing aerobatic flying.
A popular characterization for aerobatics is "stunt flying." This may describe aerobatics as it is performed at airshows. However, in competition aerobatics emphasis is on precise performance of a sequence of given or chosen aerobatic maneuvers, while potentially dangerous flying (especially breaking the safety altitude (200m above ground level in the unlimited category)) results in penalties ranging from deduction of points to disqualification[1].
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[edit] Levels
There are five levels in US (and others who adopt the US model) aerobatic competition,
- Beginner
- Sportsman
- Intermediate
- Advanced
- Unlimited
- 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 programs. 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.
[edit] The aerobatic box
The aerobatic box (pictured at right) is a 1000 meter cube of airspace in which the airplane must remain while performing the sequence. White ground markers at each corner of the box make it visible to the pilot from the air. A center line is also marked (parallel to the judges, the A-Axis) and it is along this line that most figures are flown.
The B-Axis (perpendicular to the A-Axis, and intersecting the judges) is used for "cross box correction." The official wind direction (according to the judges) always blows parallel to the A-Axis. This, however, does not always reflect reality, and generally during the course of a sequence the flyer will drift either toward or away from the judging line. Maneuvers flown along the B-Axis can be either extended or shortened to obtain the best positioning.
The box floor is 1480 ft (450 m) above ground level (AGL) for beginners which is reduced to 330 ft (100 m) AGL for unlimited competitors. The ceiling is 1000 m above the floor (thus forming the cube.) Before the competition starts, one of the contestants will mark the box by flying along the boundaries (both perimeter and floor levels for each category.) This allows the judges to visualize it in the sky.
At 300 km/h the pilot has exactly 12 s from entering the box on the one side before exiting the box on the other. When wind drift (maybe an extra 20 km/h) and a safety margin (there are penalties for flying outside the box) are considered, pilots are down to approximately 10 s. Obviously the pilot needs to turn around at either edge of the box, so that means two figures in ten seconds; competition fliers don't have much thinking time.
[edit] Competition judging
Each competition may have between five and nine judges. They are positioned between 150 and 250 meters back from the edge of the box, facing the A-Axis. They declare an official wind parallel to the A-Axis which either blows from their left or right (depending, obviously, on weather conditions.)
Corner judges monitor a pilot's excursion from the box and assign penalties. Penalties are also incurred by flying below the floor (which could lead to disqualification) and above the ceiling (generally not enforced.)
[edit] Points, the K-Factor and the Aresti Catalog
A sample aerobatic sequence has been prepared which gives the short hand Aresti notation and a good verbal description of how the sequence should be flown.
[edit] Governing bodies
The Fédération Aéronautique Internationale is the international governing body for all airborne sports, including competition aerobatics. It appoints clubs in various countries to handle regional events. For example the International Aerobatic Club governs aerobatics in the United States, and in South Africa the FAI has appointed the Aeroclub of South Africa which in turn appointed the Sport Aerobatic Club of South Africa to manage all aerobatic events. In the UK, The Royal Aero Club has appointed the British Aerobatic Association to handle all domestic aerobatics competitions.
[edit] See also
- FAI World Grand Prix
- European and World Glider Aerobatic Championships
- List of articles about Aerobatic pilots
- International Aerobatic Club (USA), British Aerobatic Association (UK)
