Period of service

(1) Every person deemed to be enrolled in the Air Defence Reserve shall be liable for service— (a) if he belongs to any of the classes specified in clauses (a) to (f) of sub-section (1) of section 11, until he has completed his forty-second year; (b) if he belongs to any of the classes specified in clauses (g) and (h) of the said sub-section, until he has completed his fifty-fifth year. (2) Every such person, on attaining the age specified in sub-section (1), shall cease to be a member of the Air Defence Reserve.