AC 91–57 is an FAA Advisory Circular (AC) (Subject: Model Aircraft Operating Standards) that outlines, and encourages voluntary compliance with, safety standards for model aircraft operators.
In 1981, in recognition of the safety issues raised by the operation of model aircraft, the FAA published this brief AC for the purpose of providing guidance to persons interested in flying model aircraft as a hobby or for recreational use. This guidance encourages good judgment on the part of model aircraft operators so that persons on the ground or other aircraft in flight will not be endangered. The AC contains among other things, guidance for site selection. Users are advised to avoid noise sensitive areas such as parks, schools, hospitals, and churches. Hobbyists are advised not to fly in the vicinity of spectators until they are confident that the model aircraft has been flight tested and proven airworthy. Model aircraft should be flown below 400 feet above the surface to avoid other aircraft in flight. The FAA expects that hobbyists will operate these recreational model aircraft within visual line-of-sight.
Non-applicability to commercial operations
Some commercial operators of unmanned aircraft systems have mistakenly used this AC as a basis for commercial flight operations. However, under FAA policy, AC 91–57 only applies to modelers, and thus specifically excludes its use by persons or companies for business purposes.
- "Docket No. FAA-2006-25714 Unmanned Aircraft Operations in the National Airspace System" (PDF). Federal Aviation Administration. February 6, 2007. Archived from the original (PDF) on 2014-06-10. Retrieved 2014-05-28.