Competition aerobatics

Competition aerobatics is an air sport in which judges rate the skill of pilots performing aerobatic flying. It is practiced in both piston-powered single-engine airplanes and gliders.

An aerobatic competition is sanctioned by a national aero club, its designee, or in the case of international competitions, by the Fédération Aéronautique Internationale (FAI). The sanctioning body establishes the rules that apply to the competition, including entry qualifications for all participants, operating procedures and judging criteria.

A pilot enters a competition in a category of his or her choice, which defines the level of difficulty of the aerobatic sequences flown. Within each category, a pilot flies one or more flight programs. Each flight receives a total score from the judges; ranking each pilot's combined total scores for all flight programs within each category determines that category's winner.

Categories

Five power categories are flown in the U.S. (and other states that adopt the U.S. model). They vary by difficulty of the individual aerobatic maneuvers they contain, as well as the combination of those maneuvers within the sequence. In order of increasing difficulty, the power categories are:

• Primary
• Sportsman
• Intermediate
• Advanced
• Unlimited

Some aero clubs include a Classic category for airplanes without inverted fuel and oil systems. The sequences flown are similar to those flown in the Sportsman category.

Three glider categories are:

• Sportsman
• Intermediate
• Unlimited

Categories flown in a competition are announced in advance.

Flight programs

Within each category, each pilot flies one or more flight programs. They are:

• Known: Determined each year by the FAI or the national aero club. It is flown by all competitors at all contests all year long. This is sometimes known as the Q (for qualifying) program.
• 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 about 12 hours before the competition. The figures are chosen by either teams or pilots, each submitting a single figure. Under CIVA rules pilots fly two unknown sequences. In Local contests often the governing body or the contest chief judge choose the unknown sequence. The pilots must not practice before flying the unknown sequence. (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.

Aerobatic box

File:Aerobatic box.svg

The aerobatic box is a volume of airspace in which the aircraft must remain while performing a sequence. Its length and width are each . Its height varies based on whether FAI, national aero club or local rules apply to the competition. White ground markers at each corner of the box make it visible to the pilot from the air. For most categories, penalties are assessed for flight outside the aerobatic box.

The box has two axes, the identification of which is based on the location of the judges. The X-Axis (called the A-Axis by some aero clubs), runs across the line of sight of the judges. It is along this axis that most figures are usually flown. In some contests a center line is marked along the middle of the X-Axis.

The Y-Axis (called the B-Axis by some aero clubs) runs perpendicular to the X-Axis, toward and away from the judges. This axis is used for cross-box position correction. The official wind direction is always declared by contest officials to be along the X-Axis. This, however, does not always reflect reality, and generally during the course of a sequence the competitor will drift either toward or away from the judging line. The competitor can extend or shorten maneuvers flown along the Y-Axis to obtain the desired positioning.

The box floor is as high as 460 metres (1,510 ft) above ground level (AGL) for Primary level competitors and as low as AGL for Unlimited level competitors. The box ceiling is as high as above its floor. Before a category starts, a competitor will mark the box by flying along its boundaries at its floor. This allows the judges to visualize the box in the sky and prepares them to adjudge an aircraft flying below the box floor.

At a groundspeed of 300 kilometres per hour (190 mph) the pilot has 12 seconds from entering the box on the one side before exiting the box on the other.

Judging

File:Arestisequence.png

An aerobatic sequence in Aresti notation.

Each category within a competition may have between 3 and 9 grading judges, each of whom is accredited by the contest's sanctioning body. They are positioned between 150 and 250 metres (490 and 820 ft) back from the edge of the box, at the center of the X-Axis and facing that axis. Each grading judge is assisted by an assistant judge, who reads Aresti notation and verbalizes to the grading judge each figure to be flown, and a recorder (also called a writer or scribe), who records scores, commentary and ancillary information on a competitor's score sheet. For some flight programs, a single individual may serve concurrently as assistant judge and recorder.

A grading judge assesses the quality of each figure flown according to well-defined criteria and assigns it a numerical score between 0 and 10. Under FAI and some national aero clubs' rules, the judge may also assign a score of "hard zero", indicating that the wrong figure was flown. At the conclusion of each flight, the grading judge assigns a presentation score based on the competitor's placement of figures throughout the aerobatic box. A grading judge also determines if the competitor has flown below the floor of the box or above its ceiling. Each grading judge is further charged with assessing whether a competitor is flying safely and advocating for the competitor's disqualification if not.

A chief judge oversees the operation of the judging line. He or she is often responsible for sequencing competitors into the aerobatic box, identifying and resolving judging and safety issues, reviewing competitors' score sheets, assessing penalties, monitoring the aerobatic box for traffic conflicts, conducting briefings for pilots and judging line personnel, and certifying scores. A chief judge is typically assisted by 2 or more individuals. In some competitions, a chief judge may concurrently serve as a grading judge.

Corner judges (also called boundary judges or line judges) are positioned at the edge of the buffer zones, 50 metres (160 ft) along each axis beyond marked corners of the aerobatic box. They monitor and record each excursion beyond the buffer zone; the competitor earns a penalty for each such excursion. Each corner judge guards 2 of the 4 lines that define the box. In most competitions, 2 corner judges are used, located at opposing corners. In FAI competitions, 4 corner judges are used, one at each corner. Two judges guard each line; they must agree that a competitor has crossed a boundary in order for the competitor earn a penalty.

Deadline judges are positioned along a deadline, if one has been established by the contest's sanctioning body. They monitor and record each infringement of the deadline. The competitor earns a penalty for each such infringement, that penalty being more severe than an excursion out of the aerobatic box.

Judging Downgrades Summary

Here is a précis of the principal "faults" that you should look for and the number of marks to deduct whilst you are applying standard CIVA rules of critique to sequence programmes at all levels.

At the entry to and exit from EVERY figure element

Horizontal start & finish Lines	Deducción
Off axis left or right n-deg	1 point/5 deg
Climbing or diving n-deg	1 point/5 deg
One wing low n-deg	1 point/5 deg
No distinct line drawn	1 point each
Flying in wrong direction on the "A" axis	Mark = Hard Zero (HZ)

Family 1 - lines and angles

Horizontal 45's & Verticals	Deducción
Climbing or diving n-deg (before or after roll)	1 point/5 deg
Steep or shallow n-deg (before or after roll)	1 point/5 deg
Positive or negative n-deg (before or after roll)	1 point/5 deg
No line drawn before or after roll	1 point each
Longer or shorter line before or after roll	1 to 3 points

Family 2 - turns and rolling turns

Turns	Deducción
Rolling entry or exit (i.e. a "co-ordinated" turn)	1 to 2 points
Bank angle too shallow (less than 60 deg)	1 point/5 deg
Bank angle varied	1 point/variation

Rolling Turns	Deducción
Roll rate varied	1 point/variation
Roll stopped or turn and then restarted	2 points
Not an even integration of rolls at end	1 point/5 deg
Not enough / too many rolls or a flick-roll seen	Mark = hard zero

Both Types	Deducción
Turn rate or radius varied	1 point/variation
Climbing or diving in turn	1 point/5 deg

Exit	Deducción
Was n-deg early or late	1 point/5 deg

Family 3 - combinations of lines

All Figures	Deducción
Smaller or larger 2nd etc. corner	1 to 3 points
Longer or shorter 2nd etc. line	1 to 3 points

Family 5 - stall turns

Up/down Lines	Deducción
Up/down-line pos/neg/left/right n-deg (before or after roll)	1 point/5 deg
Short, long or no line drawn up/down (before or after roll)	1 to 3 points

The Turn	Deducción
Turn-around too wide (pivot beyond wingtip)	1 point/wing length
Rolled or pitched n-deg in turn-around	1 point/5 deg
Exit pull or push radius smaller or larger	1 to 3 points

Family 6 - Tail Slides

Up/Down Lines	Deducción
Up/down-line pos/neg/left/right n-deg (before or after roll)	1 point/5 deg (was 2 per 5 - beware!)
Short, long or no line drawn up/down (before or after roll)	1-3 points

The Slide	Deducción
No slide seen	Mark = Perception Zero (PZ)
Yawed or rolled n-deg in slide	1 point/5 deg
Exit pull/push radius smaller or larger	1 to 3 points
Pitched the wrong way (wheels up or down)	Mark = Hard Zero (HZ)

Family 7 - Loops and Eights

Half & Full Loops	Deducción
Large or small radius at top or in 1st/2nd etc. quarter	1 to 3 points
Line drawn between roll and looping segment	2 points
Roll not central in looping segment	1 to 3 points
Off axis during looping segment	1 point/5 deg
Higher or lower exit	1 to 3 points

Eights	Deducción
Smaller or larger 2nd half	1 to 3 points
Lower or higher 2nd half (horizontal)	1 to 3 points

With Corners	Deducción
Longer or shorter 2nd etc. line length	1 to 3 points
Larger or smaller 2nd etc. corner	1 to 3 points
Up/down-line pos/neg/left/right n-deg {before or after roll}	1 point/5 deg
1st/2nd etc. 45 steep or shallow {before or after roll}	1 point/5 deg
Horizontal segment off axis left/right/up/down	1 point/5 deg

Family 8 - Combinations of Lines, Angles and Loops

Humpty Bumps	Deducción
Up/down-line pos/neg/left/right n-deg (before or after roll)	1 point/5 deg
Rolled or yawed in half-loop	1 point/5 deg
Larger or smaller 2nd quarter loop in half-loop	1 to 3 points
Push instead of pull, or pull instead of push	Mark = hard zero

Family 9 - Rolls and Spins

Slow Rolls	Deducción
Rolled n-deg short or too far	1 point/5 deg
Roll barrelled (pitched and/or yawed whilst rolling)	1 point/5 deg
Roll rate varied	1 point/variation
Axis changed left/right/up/down n-deg during/after roll	1 point/5deg
Hesitation at random point	2 points
Wrong type of roll substituted	Mark = Hard Zero (HZ)

Hesitation Rolls	Deducción
Climbed or sank in knife	1 to 2 points
Slower or faster 2nd etc. half/quarter/eighth	1 to 3 points
Under/over rotated 1st/2nd etc. half/quarter/eighth	1 point/5 deg
Hesitation missed (wrong type of roll substituted)	Mark = Hard Zero (HZ)

Flick Rolls	Deducción
Part flicked and part aileron'd roll	2 to 5 points
Not flicked (no stall seen)	Mark = Perception Zero (PZ)
Positive instead of negative, or neg instead of pos	Mark = Hard Zero (HZ)

Combinations Of Rolls	Deducción
Any line between two rolls	At least 2 points
Significant(?) line between rolls	Mark = Hard Zero (HZ)
Same direction when opposite required (or vice versa)	Mark = Hard Zero (HZ)
Wrong number of rolls where linked	Mark = Hard Zero (HZ)

Rolls immediately prior to or just after looping	Deducción
Any line between stopping loop/roll and starting roll/loop	At least 2 points
Roll starts before loop finishes	1 point/5 deg (from required line)
Significant line between rolls	Mark = Hard Zero (HZ)

Spin Entry	Deducción
Entry not stalled, and/or "rolled" in – not spinning	Mark = Perception Zero (PZ)
Flicked entry (too fast)	Mark = Perception Zero (PZ)

Spin Exit	Deducción
Spin rotation short or too far n-deg	1 point/5 deg
Line after was positive or negative n-deg	1 point/5 deg
No line drawn after	Mark = Hard Zero (HZ)

Governing bodies

The FAI is the international governing body for all airborne sports. Its Commission Internationale de Voltige Aerienne (CIVA) governs competition aerobatics. While FAI itself oversees international competitions, it recognizes national aero clubs to regulate competition aerobatics locally. A national aero club often delegates this responsibility to an affiliate organization focused on aerobatics.

In the U.S., the International Aerobatic Club (IAC) is the National Aeronautic Association's delegate for aerobatics; in the UK, the Royal Aero Club designates the British Aerobatic Association (BAeA) to fill this roll. In South Africa the FAI appoints the Aeroclub of South Africa which in turn appoints the Sport Aerobatic Club of South Africa to manage all aerobatic events.

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)
• Two Seater and Retro Glider Aerobatic Cup Zbraslavice

External links

• FAI Sporting Code Section 6, "Regulations for the Conduct of International Aerobatic Events, Part 1 - Powered Aircraft"
• Judging tutorial for 2011, The British Aerobatic Association
• International Aerobatic Club
• Commission Internationale de Voltige Aerienne (FAI Aerobatics Commission)
• Sport Aerobatic Club of South Africa
• Olan free software for design of aerobatic sequences
• Aerobatic maneuver website