Aeronautical knowledge recency.
A person may not operate a small unmanned aircraft system unless that person has completed one of the following, within the previous 24 calendar months:
(a) Passed an initial aeronautical knowledge test covering the areas of knowledge specified in § 107.73(a);
(b) Passed a recurrent aeronautical knowledge test covering the areas of knowledge specified in § 107.73(b); or
(c) If a person holds a pilot certificate (other than a student pilot certificate) issued under part 61 of this chapter and meets the flight review requirements specified in § § 61.56, passed either an initial or recurrent training course covering the areas of knowledge specified in § 107.74(a) or (b) in a manner acceptable to the Administrator.