Your deadline for appealing from any adverse action on your conductor certification is going to be 120 days. That's even shorter than the deadline for retaliation and discrimination. First you'll have a hearing before carrier operating department officials. Then the losing side can appeal to the FRA "Operating Crew Review Board," which conducts a review of written submissions by the parties and the issues a written decision. The side that loses before the Operating Crew Review Board can then request a formal evidentiary hearing before an Administrative Law Judge. That side that loses before the Administrative Law Judge can then seek review by the Federal Railroad Administrator.
I keep saying "the losing side" because if you win at any point in this process, the railroad can appeal.