Alerts for terrain, obstacle, and power lines are suppressed when the aircraft is within 5 NM of an airport and the projected position of the aircraft falls within the Runway Suppression Area surrounding a published runway. These Runway Suppression Areas prevent potential nuisance alerts when the aircraft is descending near an airport. The suppressed area extends 1 NM from the runway thresholds and 0.75 NM from the sides of the runway, i.e., the suppressed area is the runway length plus 2 NM and the runway width plus 1.5 NM.