Middle Marker
What is middle marker?
The middle marker is part of an Instrument Landing System (ILS) and indicates your position along the approach as you near the runway—traditionally where the aircraft reaches the decision height on a standard approach. When you fly over it, you'll receive an audible and visual signal in the cockpit, alerting you that the runway is close. Think of it as the "almost there" checkpoint on an ILS approach.
Also known as: MM, middle marker beacon
Studying for an FAA written test?
Terms like middle marker show up on the FAA knowledge test. Study them in context with ACS-aligned practice questions, AI explanations, and the cited FAA handbook reference behind every answer — free to start.
Learn more in the library
Related terms
- maximum takeoff weight
- maximum weight
- mechanical turbulence
- microburst
- military operations area
- minimum controllable airspeed
- minimum crossing altitude
- minimum descent altitude