EN ROUTE MINIMUM SAFE ALTITUDE WARNING (E-MSAW)
A function of the EAS that aids the controller by providing an alert when a tracked aircraft is below or predicted by the computer to go below a predetermined minimum IFR altitude (MIA).
Listed in the Pilot/Controller Glossary as a cross-reference to EN ROUTE MINIMUM SAFE ALTITUDE WARNING (E-MSAW), whose text is shown above.
Source FAA Pilot/Controller Glossary · checked 2026-08-25