An air attaché typically represents the chief of a foreign air force in the 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.
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.