49 CFR 825.15 - Issues on appeal.
The only issues that may be considered on appeal are:
(a) A finding of a material fact is erroneous;
(b) A necessary legal conclusion is without governing precedent or is a departure from or contrary to law or precedent;
(c) A substantial and important question of law, policy, or discretion is involved; or
(d) A prejudicial procedural error has occurred.