§63.23. Special purpose flight engineer and flight navigator certificates: Operation of U.S.-registered civil airplanes leased by a person not a U.S. citizen. — Inbound Citations

(a) Except as provided in § 63.23 and paragraph (b) of this section, a certificate or rating issued under this part is effective until it is surrendered, suspended, or revoked.

A person who is neither a United States citizen nor a resident alien is issued a certificate under this part (other than under § 63.23 or § 63.42) outside the United States only when the Administrator finds that the certificate is needed for the operation of a U.S.-registered civil aircraft.

(iii) “Issued under, and subject to, § 63.23 of the Federal Aviation Regulations.”