(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.
(b) A flight engineer certificate (with any amendment thereto) issued
under §63.42 expires at the end of the 24th month after the month in which
the certificate was issued or renewed. However, the holder may exercise
the privileges of that certificate only while the foreign flight engineer
license on which that certificate is based is effective.
(c) Any certificate issued under this part ceases to be effective if it
is surrendered, suspended, or revoked. The holder of any certificate
issued under this part that is suspended or revoked shall, upon the
Administrator's request, return it to the Administrator. (Sec. 6,
80 Stat. 937, 49 U.S.C. 1655; secs. 313, 601, 602, Federal Aviation Act of
1958, as amended (49 U.S.C. 1354, 1421, and 1422); sec. 6(c), Department
of Transportation Act (49 U.S.C. 1655(c)); Title V, Independent Offices
Appropriations Act of 1952 (31 U.S.C. 483(a)); sec. 28, International Air
Transportation Competition Act of 1979 (49 U.S.C. 1159(b)))