In 1994, the FAA Act of 1958 was ammended, and the public laws authorizing the FAA were placed in Title 49 of the United States Code. Those portions of the public law affecting aviation were re-codified, and what was 609, fell under 49 USC 44709. It is the actual Law, not a regulation, authorizing the FAA to re-examine certificate holders certificates at any time.
TITLE 49--TRANSPORTATION
SUBTITLE VII--AVIATION PROGRAMS
PART A--AIR COMMERCE AND SAFETY
subpart iii--safety
CHAPTER 447--SAFETY REGULATION
Sec. 44709. Amendments, modifications, suspensions, and
revocations of certificates
(a) Reinspection and Reexamination.--The Administrator of the
Federal Aviation Administration may reinspect at any time a civil
aircraft, aircraft engine, propeller, appliance, air navigation
facility, or air agency, or reexamine an airman holding a certificate
issued under section 44703 of this title.
(b) Actions of the Administrator.--The Administrator may issue an
order amending, modifying, suspending, or revoking--
(1) any part of a certificate issued under this chapter if--
(A) the Administrator decides after conducting a
reinspection, reexamination, or other investigation that safety
in air commerce or air transportation and the public interest
require that action; or
(B) the holder of the certificate has violated an aircraft
noise or sonic boom standard or regulation prescribed under
section 44715(a) of this title; and
(2) an airman certificate when the holder of the certificate is
convicted of violating section 13(a) of the Fish and Wildlife Act of
1956 (16 U.S.C. 742j-1(a)).