Runway Awareness and Advisory System

The Runway Awareness and Advisory System (RAAS) is an electronic detection system that notifies aircraft flight crews on the ground of their position relative to their allocated runway.

[1] According to Honeywell Aerospace, who developed the original RAAS, runway incursions are a leading cause of aviation accidents and fatalities, costing approximately $1 billion annually.

[2] RAAS functions by providing audible alerts to confirm runway identification, and also provides an aural alarm if it detects undue acceleration (indicating an attempt to take off) while the aircraft is on any taxiway instead of a designated runway.

Its function is possible by a software enhancement to the aircraft's terrain awareness and warning system (TAWS) or enhanced ground proximity warning system (EGPWS).

[5] In 2016 Ryanair committed to equip all its fleet with RAAS,[6] which was mostly complete by 2019.