14 C.F.R. § 61.17 Temporary certificate.
Title 14 - Aeronautics and Space
(a) A temporary pilot, flight instructor, or ground instructor certificate or rating is issued for up to 120 days, at which time a permanent certificate will be issued to a person whom the Administrator finds qualified under this part. (b) A temporary pilot, flight instructor, or ground instructor certificate or rating expires: (1) On the expiration date shown on the certificate; (2) Upon receipt of the permanent certificate; or (3) Upon receipt of a notice that the certificate or rating sought is denied or revoked.
Title 14: Aeronautics and Space
PART 61—CERTIFICATION: PILOTS, FLIGHT INSTRUCTORS, AND GROUND INSTRUCTORS
Subpart A—General
§ 61.17 Temporary certificate.

