14 CFR § 137.17

An agricultural aircraft operator certificate may be amended—

On the Administrator's own initiative, under section 609 of the Federal Aviation Act of 1958 (49 U.S.C. 1429) and part 13 of this chapter; or

Upon application by the holder of that certificate.

An application to amend an agricultural aircraft operator certificate is submitted on a form and in a manner prescribed by the Administrator. The applicant must file the application with the responsible Flight Standards office for the area in which the applicant's home base of operations is located at least 15 days before the date that it proposes the amendment become effective, unless a shorter filing period is approved by that office.

The responsible Flight Standards office grants a request to amend a certificate if it determines that safety in air commerce and the public interest so allow.

Within 30 days after receiving a refusal to amend, the holder may petition the Executive Director, Flight Standards Service, to reconsider the refusal.