3.—(1) A person may be enlisted in the Royal Air Force for such a term as is specified in paragraph (2) of this regulation beginning with the date of his attestation.
(2) The term referred to in paragraph (1) shall be a term expiring on a date falling between 6 months and 22 years after the relevant date.
(3) The term for which a person may be enlisted may be a term wholly of air force service or may be a term partly of air force service and partly of service with the air force reserve.