International Miniature Aerobatic Club
Governing body for scale aerobatic model aircraft contests.
The International Miniature Aerobatic Club (IMAC) is a non-profit that governs scale aerobatic model aircraft competitions. Founded in 1974 with 97 charter members, it runs precision contests involving hundreds of pilots across the United States and Eastern Canada. For safety, all IMAC events take place at flying clubs sanctioned by the Academy of Model Aeronautics or the Model Aeronautics Association of Canada.
Competitions are divided into five main classes, with an optional sixth at some events. Pilots fly known sequences and, on the day of competition, unknown programs that may only be attempted once (except in Basic class, which has no unknowns). Winning five contests in a season requires moving up to the next class at the start of the new season.
Basic class (411) is open to all pilots with monoplane or biplane aircraft; no model pilot or dashboard is required. Sportsman (412) limits unknown programs to one full roll on any line and one half roll on any 45-degree line, with no combination roll elements. Intermediate (415) restricts unknowns to no more than 1½ rolls on combination or single roll elements (excluding spins) and limits rolls to one with any looping maneuver. Advanced (413) caps unknowns at 2 rolls on combination or single roll elements (excluding spins) and limits rolls to 1½ with looping maneuvers. Unlimited (414) also caps unknowns at 2 rolls on combination or single roll elements (excluding spins), but allows up to 2½ rolls on downlines and 3 rolls on uplines for combination roll elements. Freestyle class requires a pilot to compete in one of the five standard classes; separate awards are given, and pilots are judged on technical merit, artistic impression, and positioning.
All sequences are described using Aresti notation, providing a standard way to document permitted maneuvers for pilots and judges. Pilots are evaluated on the quality and precision of their flying. Each year, an official IMAC committee reviews and adjusts the sequences within each class to introduce new challenges. Contestant judging is typically used to score pilots and assign rankings, with top scorers receiving trophies and peer recognition.
- Founded
- 1974
- Chartered members
- 97
- Classes
- Basic, Sportsman, Intermediate, Advanced, Unlimited, Freestyle
- Regions
- Northeast, Southeast, North central, South central, Northwest, Southwest
Lore & Background
IMAC was founded in 1974 with 97 chartered members. The organization hosts competitions only at Academy of Model Aeronautics or Model Aeronautics Association of Canada sanctioned flying clubs for safety reasons. Contests are segregated into five class levels—Basic, Sportsman, Intermediate, Advanced, and Unlimited—with an optional Freestyle class at some events. Each class has specific restrictions on unknown programs, which are given the day of competition and can only be attempted once, except in Basic class which does not fly unknowns. If a contestant wins five contests in a season, they must advance to the next higher class at the start of the new season. Sequences within each class are described using Aresti notation, providing a standard method for documenting permitted aerobatic maneuvers. Pilots are judged on the quality and precision of their flying skills. Contestant judging is generally used to score pilots and assign rankings within each class, with top scorers receiving trophies and peer recognition. Contest events are regionalized by states and provinces across six regions: Northeast, Southeast, North central, South central, Northwest, and Southwest.
Reader's Guide
IMAC's significance lies in its role as the primary organizer of precision aerobatic competitions for scale model aircraft in the United States and Eastern Canada. By establishing five class levels with progressive difficulty, the organization provides a structured pathway for pilots to develop their skills. The use of Aresti notation standardizes maneuver documentation, ensuring consistency for both pilots and judges. The requirement for pilots to advance after winning five contests in a season maintains competitive balance and encourages growth. The Freestyle class, which requires participation in a standard class, offers an additional avenue for creative expression judged on Technical Merit, Artistic Impression, and Positioning. Regionalization of contests allows pilots to compete locally while still participating in a unified national framework. The organization's longevity since 1974 and its hundreds of participating pilots demonstrate its enduring impact on the hobby of radio-controlled aerobatics.
Did You Know?
- Basic class pilots do not fly unknown programs.
- Freestyle class requires pilots to compete in one of the five standard classes to be eligible.
Frequently Asked Questions
What is the International Miniature Aerobatic Club?
IMAC is a non-profit organization that oversees scale aerobatic model aircraft competitions. It was established in 1974 and now coordinates events attended by hundreds of pilots throughout the United States and Eastern Canada.
How many competition classes does IMAC offer?
IMAC structures its contests into five primary classes—Basic, Sportsman, Intermediate, Advanced, and Unlimited—with an optional sixth Freestyle class at select events. On competition day, pilots fly both a known sequence and a surprise program drawn at the venue.
When and how was IMAC founded?
The club was chartered in 1974 by a group of 97 founding members who wanted a unified governing body for scale aerobatic RC aircraft contests. Since then it has grown into a multi-regional organization with divisions across the Northeast, Southeast, North Central, South Central, Northwest, and Southwest.
Where are IMAC events held and who sanctions them?
Every IMAC competition must take place at a flying club that holds official sanctioning from either the Academy of Model Aeronautics or the Model Aeronautics Association of Canada. This requirement enforces a consistent safety framework across all sanctioned venues.
Why is IMAC important to the RC aircraft community?
IMAC serves as the central body that standardizes rules, class structures, and competition formats for scale aerobatic model flying. Its regional divisions give pilots a clear progression path from entry-level Basic class all the way up to Unlimited and Freestyle competition.
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