What is the distance between parallel runways that require precision runway guidance monitoring radar?

• A. 2500-4300 ft
• B. 1000-2000 ft
• C. 5000-7000 ft
• D. 700-900 ft

Answer: (A)

When two parallel runways are close enough that standard radar surveillance can’t reliably ensure independent, simultaneous precision approaches, an enhanced monitoring system is used to keep both aircraft clearly tracked. Precision Runway Monitor radar provides the extra precision needed to watch two aircraft on parallel approaches and maintain safe separation. This support is required when the runways’ centers are separated by about 2,500 to 4,300 feet. Within this range, PRM helps controllers manage potential conflicts that normal radar coverage might miss. If the runways are farther apart than roughly 4,300 feet, independent precision approaches can usually be conducted without PRM; if they’re closer than about 2,500 feet, the situation typically isn’t suitable for independent precision approaches.