Flap track fairing systems are split into a forward immovably fixed portion and an aft movable portion. The fixed forward portion is immovably attached to the main wing structure of an aircraft while the movable aft portion is attached either to the movable components of the flap deployment mechanism or to the lower surface of the flap. A separation line between the forward movable portion and the aft fixed portion is provided such that the movable portion does not interfere structurally with the flap fairing structure during a flap extension/retraction cycle. An airflow deflector is positioned near a forward separation edge of the aft fairing portion so as to be positioned within a gap defined between the forward edge of the aft fairing portion and a rearward edge of the forward fairing portion when the flap is in the deployed configuration thereof to thereby deflect airflow away from the interior space of the fairing.