An air attaché is an Air Force officer who is part of a diplomatic mission; this post is normally filled by a high-ranking officer.
An air attaché typically represents the chief of his home air force in the foreign country where he serves. The day-to-day responsibilities include maintaining contacts between the host nation and the attaché's air force. This includes arranging official visits, exchange postings and exercises. Other duties of an air attaché also include traveling around the host country to determine the extent of the air force infrastructure of the host country and then filing intelligence reports with their superiors in the home air force. Many of the travels are disguised as other types of trips, such as vacations or family trips, otherwise the air attaché could be expelled for spying if caught doing so.
On a smaller diplomatic mission which does not have its own air attaché, the role of the air attaché is carried out by the defence attaché who also deals with army and navy matters. Sizable diplomatic missions may be served by both an air attaché and an assistant air attaché.