14 CFR §406.133

1. (a)Time. A party must file with the Federal Docket Management System and serve on each other party any amendment to a complaint or an answer as follows:
   1. (1)Not later than 15 days before the scheduled date of a hearing, a party may amend a complaint or an answer without the consent of the administrative law judge.
   2. (2)Less than 15 days before the scheduled date of a hearing, the administrative law judge may allow amendment of a complaint or an answer only for good cause shown in a motion to amend.
2. (b)Responses. The administrative law judge must allow a reasonable time, but not more than 20 days from the date of filing, for other parties to respond to an amendment to a complaint or answer.