4.—(a) (i) Subject to sub-paragraph (ii), a certificate of test required by article 22(5) of this Order in respect of a Commercial Pilot’s Licence (Balloons) shall not be valid in relation to a flight made more than 13 months after the date of the test which it certifies and in respect of any other licence shall not be valid in relation to a flight made more than 13 months in Cases A, B, E and H, or more than 6 months in Cases C, D and G, after the date of the test which it certifies.
(ii)In the case of Cases C, D and G 2 certificates of test shall together be deemed to constitute a valid certificate of test if they certify flying tests conducted on 2 occasions within the period of 13 months preceding the flight on which the functions are to be performed, such occasions being separated by an interval of not less than 4 months, and if both certificates are appropriate to those functions.
(b)A certificate of test required by article 22(6) of this Order shall not be valid in relation to a flight made more than 13 months in the case of an instrument rating (aeroplanes), an instrument rating (helicopters) and an assistant flying instructor’s rating or more than 25 months in the case of an instrument meteorological conditions rating (aeroplanes) and a flying instructor’s rating, after the date of the test which it certifies.