5.—(1) A certificate of revalidation required by article 157 for a flight instructor’s certificate (SLMG), a flight instructor’s certificate (microlight), or an flight instructor’s certificate (restricted) (microlight) must be signed by a person authorised by the CAA to sign certificates of this kind and certify—
(a)the certificate to which the certificate of revalidation relates;
(b)that on a specified date the holder has passed an appropriate test of the holder’s ability to exercise the privileges of the certificate;
(c)the specified date; and
(d)the date on which the period of validity of the certificate expires in accordance with sub-paragraph (2).
(2) If the rating—
(a)has not expired, the new certificate is valid for 36 months from the end of the month which includes the expiry date of the existing certificate; and
(b)has expired, the new certificate is valid for 36 months in addition to the remainder of the month in which the date of test falls.