三級航空交通事務員主要接受訓練，以執行航空交通事務員的以下職務：
(a) 向航空交通管制中心及指揮塔提供支援服務；
(b) 提供航空資料服務；
(c) 協助進行技術研究；
(d) 協助處理各項航空事務申請、解答查詢、處理投訴及編製投訴統計數字；以及
(e) 協助審核和視察航空活動。

航空交通事務員須二十四小時輪班工作。

An Air Traffic Flight Services Officer III is mainly deployed to undergo training for performing Air Traffic Flight Services Officer’s duties in the following areas :
(a) provision of supporting service in the Air Traffic Control Centre and the Control Tower;
(b) provision of aeronautical information service;
(c) assisting in the conduct of technical research and studies;
(d) assisting in the processing of various air services applications, answering enquiries, handling complaints and compiling statistics; and
(e) assisting in the conduct of audits and inspections to aviation-related activities.

An Air Traffic Flight Services Officer is required to work shifts on a 24-hour basis.