51. An aircraft with a national certificate of airworthiness must not fly if—
(a)the continuing airworthiness of the aircraft or any component fitted to the aircraft does not meet the requirements of this Part;
(b)the aircraft does not remain in conformity with the type design approved by the CAA;
(c)the aircraft has been operated beyond the limitations of the approved flight manual or the airworthiness certificate, without subsequent appropriate action to restore airworthiness being taken;
(d)the aircraft has been involved in an accident or incident that affects the airworthiness of the aircraft, without subsequent appropriate action to restore airworthiness being taken; or
(e)the aircraft has a modification or repair for which a certificate or release to service has not been issued in accordance with this Order.