International Miniature Aerobatic Club (IMAC) is a non-profit organization devoted to flying scale aerobatic model aircraft. IMAC is the main governing body responsible for hosting precision aerobatic contests with hundreds of pilots across the United States and Eastern Canada. The organization was founded in 1974 with 97 chartered members.
For safety reasons, IMAC competitions are hosted only at Academy of Model Aeronautics or Model Aeronautics Association of Canada sanctioned flying clubs.
IMAC contests are segregated into five class levels with an optional sixth class at some events. In addition to known programs, a pilot is given unknown programs the day of the competition that can only be attempted once (except the basic class, which does not fly unknowns). If a contestant wins five contests in a season, they are required to advance to the next higher class at the beginning of the new season.
Sequences within each class are described using Aresti notation. This provides a standard method of documenting aerobatic maneuvers permitted within each class level for both pilots and judges. Pilots are judged on the quality and precision of their flying skills.
Each year, an official IMAC committee reviews the flying sequences within each class to makes adjustments as well as to offer new challenges for pilots. Contestant judging is generally used to score participating pilots and assign a ranking within each class. Those achieving the highest scores in their class are rewarded with trophies and peer recognition for their accomplishments. Contest events are regionalized by states and provinces.