49 CFR 821.49 - Issues on appeal.
(a) On appeal, the Board will consider only the following issues:
(1) Are the findings of fact each supported by a preponderance of reliable, probative and substantial evidence?
(2) Are conclusions made in accordance with law, precedent and policy?
(3) Are the questions on appeal substantial?
(4) Have any prejudicial errors occurred?
(b) If the Board determines that the law judge erred in any respect, or that his or her initial decision or order should be changed, the Board may make any necessary findings and may issue an order in lieu of the law judge's initial decision or order, or may remand the proceeding for any such purpose as the Board may deem necessary.