The Air Navigation Order 2009

National certificate of airworthiness ceasing to be in force and issue of airworthiness directives for non-EASA aircraft

19.—(1) Subject to paragraph (3), a national certificate of airworthiness or a certificate of validation issued for a non-EASA aircraft registered in the United Kingdom ceases to be in force if—

(a) the aircraft or any part of the aircraft or such of its equipment as is necessary for the airworthiness of the aircraft has been overhauled, repaired, replaced, modified or maintained;

(b) maintenance or an inspection of the aircraft or of any equipment necessary for the airworthiness of the aircraft is required by a maintenance schedule approved by the CAA for that aircraft under article 25;

(c) maintenance of the aircraft or of any equipment necessary for the airworthiness of the aircraft has been made mandatory by a directive issued by the CAA;

(d) an inspection for the purpose of ascertaining whether the aircraft remains airworthy has been made mandatory by a directive issued by the CAA; or

(e) any modification of the aircraft or of any equipment which is necessary for the airworthiness of the aircraft, has been made mandatory by a directive issued by the CAA for the purpose of ensuring that the aircraft remains airworthy.

(2) A certificate of airworthiness or a certificate of validation which has ceased to be in force under paragraph (1) becomes valid again on the issue of a certificate of release to service under this Order relating to the overhaul, repair, replacement, modification, maintenance or inspection.

(3) A certificate of airworthiness which would not be in force by reason of paragraph (1) remains in force if the aircraft is flying in the circumstances specified in article 28(3) or 29.

(4) In this article, a certificate of validation has the same meaning as specified in article 18(5).