23.—(1) Subject to section 52FH of the Act and rule 24, a military or air-force officer falling within paragraph (2) shall be qualified under that section for membership of the court for the purposes of hearing an appeal if the court administration officer considers that the necessary number of naval officers so qualified is not (with due regard to the public service) available to sit as members of the court for the purposes of that hearing.
(2) A military or air-force officer falls within this paragraph if he is of corresponding rank to that required of a naval officer and has held a commission in any of Her Majesty’s naval, military or air forces for a period of not less than three years or for periods amounting in the aggregate to not less than three years.
(3) An officer specified under this rule to sit as a member of the court for the hearing of an appeal shall not preside at the hearing.
(4) In this rule—
“air-force officer” means an officer belonging to Her Majesty’s air forces and subject to air force law; and
“military officer” means an officer belonging to Her Majesty’s military forces and subject to military law.