Pattern Competition Flying involves complex aerial maneuvers with a radio controlled model aircraft, where utmost precision and skill in controlling the model aircraft in any attitude and under all conditions is required. The model aircraft is 100% influenced by the wind and all maneuvers in the aerobatic schedules are judged relative to a point on the ground. The competitor must therefore compensate constantly for possible wind drift. Typically, pattern type model aircraft will have a fuselage length of no more than 2 meters, a wing span of less than 2 meters, and the weight must not exceed 11lbs. Power is usually an internal combustion engine, with no power limitations, but the engine has to be adequately silenced.

Flights are performed directly in front of the judges in an aerobatic zone or "box", which extends 60 degrees to the left and right of a center line, and at an elevation of no more than 60 degrees. Each time the model aircraft crosses the center line, a particular maneuver of a known (published) aerobatic schedule has to be performed, involving components such as loops, rolls, lines, spins, snap rolls, stall turns, and combinations of these. At the ends of the aerobatic box, the model aircraft is required to do turn-around maneuver to enable it to reverse its direction of travel. Generally the model aircraft is required to be flown at 150 meters from the pilot, in a plane perpendicular to the center line.

Each competitor's performance is assessed by a panel of judges who will award marks, independently from each other, between zero and ten for each maneuver. Maneuvers are assigned a difficulty factor (K-factor) depending on the complexity of the particular maneuver. Judging is based on four basic criteria: precision (or geometry), smoothness and gracefulness, positioning (display), and size of maneuver. Points are subtracted for various types of defects observed by the judges, the severity of these defects, and the number of times these defects are observed.

Got to www.NSRCA.org for more data on pattern competition flying.