Definition
Instrument approaches conducted to closely spaced parallel runways at airports equipped with the Precision Runway Monitor system. PRM uses high-update radar and specialized controller displays to monitor aircraft on simultaneous independent approaches to parallel runways spaced less than 4,300 feet apart, allowing both runways to be used for arrivals at the same time in instrument conditions. Pilots flying PRM approaches must complete specific training, monitor a second tower frequency for breakout instructions, and be prepared to immediately execute an evasive maneuver if directed by the monitor controller.
Plain English
A type of instrument approach used at airports where two runways sit close together. A special radar system watches both streams of arriving aircraft very closely so that landings can happen on both runways at the same time, even in bad weather. Pilots have to be trained for it and must be ready to turn away quickly if told to.
Context Anchor
Seen on instrument approach charts and in ATC clearances at larger airports with closely spaced parallel runways.
Derivation
Precision Runway Monitor describes the system itself: a precise radar that monitors aircraft approaching parallel runways. The term is descriptive rather than coined, and it tells you the whole purpose of the system in three words.
Why Pilots Care
Allows higher landing capacity at airports with parallel runways while maintaining required safety margins.
Intuition Check
PRM does not mean the approach itself is automatically more precise for the pilot. It means the approach is being precisely monitored so aircraft on close parallel approaches stay safely apart.
Example Sentence 1
Before accepting the PRM approach into Minneapolis, the crew reviewed the breakout procedures and tuned the monitor frequency in the standby radio.
Example Sentence 2
PRM approaches require the pilot to monitor a dedicated frequency for breakout instructions if separation is lost.