Minimum safe altitude warning (MSAW) is an automated warning system for air traffic controllers (ATCO). It is a ground-based safety net intended to warn the controller about increased risk of controlled flight into terrain accidents by generating, in a timely manner, an alert of aircraft proximity to terrain or obstacles.
Description
ICAO Doc 4444 requires that radar systems should provide for the display of safety-related alerts including the presentation of minimum safe altitude warning. The radar equipment predicts an aircraft’s position in 2 minutes based on present path of flight, and the controller issues a safety alert if the projected path encounters terrain or an obstruction. An unusually rapid descent rate on a non-precision approach can trigger such an alert.
It is worth mentioning that ICAO Doc 4444 does not provide a definition of the term MSAW. Instead the term MSAW is ambiguously used in ATC community to identify such warnings as well as for data processing systems providing the alert function.
References
- "EUROCONTROL Specification for Minimum Safe Altitude Warning" (PDF). 0.9. Eurocontrol. 19 May 2009. Retrieved 2010-05-24.
- Rules of the Air and Air Traffic Services. ICAO. Doc 4444-RAC/501.
- "Chapter 2. The Air Traffic Control System". Instrument Flying Handbook (PDF) (FAA-H-8083-15B ed.). Federal Aviation Administration Flight Standards Service. 2012. p. 5. ISBN 979-8776640544.
This article incorporates text from this source, which is in the public domain.