Competition Aerobatics for the Spectator
By Bill Hill, IAC Chapter 36
Photo credit: Laurie Zaleski
The competition arena is a block of airspace approximately 3,300 feet long by 3,300 feet wide by 3,500 feet high. For safety, a minimum height above the ground is established with severe penalty points assigned if the pilot flies below the minimum height. The minimum height above the ground is 1,500 feet for the Primary and Sportsman categories; 1,200 feet for Intermediate; 800 feet for Advanced; and 328 feet for the Unlimited category. At the start of each category flight, the first pilot will fly past the judges at the minimum height to give them a visual reference for that height.
The aerobatic box is aligned with the runway on the north side. The west end of the aerobatic box is at the end of the runway, and the middle of the box is where the judges are seated. When the pilot flies into the box, he looks down at a marked playing field. The aerobatic box markings are an L shape in each of the four corners, a T shape in the middle of each side, and a + shape in the center of the playing field. Spectators are located on the south side of the runway between the west end and the middle of the box.
Each competition category flies three flights. These flights are the Known program, the Free program, and the Unknown program.
- The Known program for each category is published by the International Aerobatic Club for each contest season.
- The Free program is designed by the pilot to take maximum advantage of his particular skills and the performance capabilities of his airplane.
- The Unknown program is a sequence of maneuvers supplied by the International Aerobatic Club for each contest. The pilot is given the program 24 hours in advance of the scheduled flight to study, and he is not allowed to fly the program in advance of the competition flight
In the Primary category, the pilots fly the same Known program for all three flights. In the Sportsman category, most pilots fly the Known program for all three flights. If a Sportsman pilot chooses to fly a Free program, he also flies it as the Unknown program.
From the spectator's point of view, once one program is flown in a category, all the other programs will have the same sequence of maneuvers, except for the Free programs. During the Free program in the Intermediate, Advanced, and Unlimited categories, the spectator will see each pilot flying a different sequence of maneuvers.
Spectators can become more involved by scoring pilot performance. Each maneuver is given a score from zero to 10 points. The scoring rules are:
- Loops are round.
- There must be a line between each maneuver, and that line must be flown at a constant height above the ground.
- During up and down lines, the airplane's attitude must be 45 or 90 degrees. Wings must be parallel to the horizon. The airplane's path will be affected by the wind, and therefore, is not judged.
- Level turns must remain at a constant height above the ground and at a constant bank angle.
- Rolls on vertical and 45-degree up-and-down lines must be in the center of the line.
- Roll rate must remain the same throughout the roll.
- During hesitation rolls, the angular change between hesitations must be the same.
- All maneuvers must start and end either parallel to or perpendicular to the runway at Borrego Valley Airport, California.
- A maneuver starts from a level flight attitude and ends in a level flight attitude.
- The maneuver can be a combination of loops, lines, rolls, and a spin, and is graded in its entirety.
- Roll rate and airspeed are not graded.
Give the flight program a presentation score of zero to 10 based on balance, flow, and overall visual appeal. The pilot with the highest total score at the end of a flight program is the winner. The contest category winner is the pilot with the highest total score at the end of the three flights.
Enjoy your contest; I hope this article will help make the experience more meaningful.
If you'd like to know the location of your nearest contest, please take a look at the Chapter Contests Calendar.