Recurrent training means periodic training required under 14 CFR part 61, 121,125, 135, or Subpart K of part 91. Recurrent training does not include training that would enable a candidate who has a certificate or type rating for a particular aircraft to receive a certificate or type rating for another aircraft.
49 CFR § 1552.1
Scope. This subpart applies to flight schools that provide instruction under 49 U.S.C. Subtitle VII, Part A, in the operation of aircraft or aircraft simulators, and individuals who apply to obtain such instruction or who receive such instruction.