The Tribunal, while hearing and deciding an appeal under section 15, shall have the power—
(a)to order production of documents or exhibits connected with the proceedings before the court martial;
(b)to order the attendance of the witnesses;
(c)to receive evidence;
(d)to obtain reports from Court martial;
(e)order reference of any question for enquiry;
(f)appoint a person with special expert knowledge to act as an assessor; and
(g)to determine any question which is necessary to be determined in order to do justice in the case.