proficiency flying duty
(6) In this section: (A) The term “aviation service” means service performed by an officer (except a flight surgeon or other medical officer) while holding an aeronautical rating or designation or while in training to receive an aeronautical rating or designation. (B) The term “operational flying duty” means flying performed under competent orders by rated or designated members while serving in assignments in which basic flying skills normally are maintained in the performance of assigned duties as determined by the Secretary concerned, and flying performed by members in training that leads to the award of an aeronautical rating or designation. (C) The term “proficiency flying duty” means flying performed under competent orders by rated or designated members while serving in assignments in which such skills would normally not be maintained in the performance of assigned duties. (D) The term “officer” includes an individual enlisted, and designated, as an aviation cadet under section 8411 of title 10 .