What is M on Airbus A320? (Magenta, Mach, Meter)

The Airbus A320 is a widely used single-aisle aircraft known for its efficiency and reliability. As pilots navigate and operate this sophisticated aircraft, they encounter various indicators and measurements that assist them in making informed decisions. Three of these vital aspects are Magenta, Mach, and Meter (M), which provide critical information to pilots during flight. In this article, we will explore the significance and functionality of Magenta, Mach, and Meter on the Airbus A320.

Magenta: Simplifying Navigation

Magenta, in the context of the Airbus A320, refers to the magenta-colored flight path displayed on the aircraft’s navigational display. This flight path indicator helps pilots visualize their planned route, making it easier to follow and maneuver accordingly. The magenta line represents the aircraft’s desired path based on the flight plan or navigational waypoints programmed into the avionics system.

During flight, pilots can view the magenta flight path indicator on the Primary Flight Display (PFD) in front of them. This display shows pertinent flight information such as altitude, airspeed, and heading, along with the magenta line indicating the planned route. This feature simplifies navigation, allowing pilots to make real-time adjustments and deviations if needed, ensuring the aircraft stays on track and reaches its destination safely.

It is important to note that the magenta flight path indicator is not just for visual guidance; it also aids in autopilot engagement. When the autopilot is engaged, it uses the magenta line as a reference for following the desired route. This automation ensures precise navigation and reduces the workload on the flight crew, especially during long-haul flights.

Mach: Indicating Speed

The Mach number is a dimensionless quantity that represents an aircraft’s speed relative to the speed of sound. On the Airbus A320, the Mach number indicator provides pilots with valuable information about the aircraft’s performance. It is displayed on the Airspeed Indicator, which is part of the PFD.

The Mach number is denoted by the letter “M” followed by a decimal number. For example, M0.82 represents 0.82 times the speed of sound. The Mach number is crucial because at higher altitudes, where air density decreases, using Mach speed becomes more accurate than relying solely on indicated airspeed. This is due to variations in air density affecting the true airspeed.

By monitoring the Mach number, pilots can ensure they are maintaining a safe and efficient speed during different phases of flight. Exceeding the maximum operating Mach number can lead to structural damage, while flying too slow can affect the aircraft’s handling and fuel efficiency. The Mach number is an essential parameter for pilots to consider, especially when planning for cruise altitudes and avoiding high-speed flight conditions.

Meter (M): A Unit of Measurement

In aviation, the term “Meter” (M) refers to the unit of measurement used for altitude. It represents the height or vertical distance between the aircraft and a reference point, typically measured in feet or meters. The use of meters as a unit of measurement is common in international aviation, where the metric system is predominant.

The altitude meter on the Airbus A320 provides pilots with accurate altitude information in real-time. The altitude is displayed on the PFD, along with other flight parameters. Pilots can use this information to maintain the desired altitude assigned by air traffic control during climb, cruise, and descent phases.

It is crucial for pilots to constantly monitor the altitude meter to ensure the aircraft remains at the correct altitude. Deviations from the assigned altitude can result in safety hazards, such as potential collisions with other aircraft. Pilots also use the altitude meter when transitioning from one altitude to another, following air traffic control instructions or navigation waypoints.

The Airbus A320’s altitude meter is equipped with various features, including altitude alerting and altitude pre-select capabilities. These features provide additional aids to pilots during flight, ensuring they maintain a safe and efficient altitude profile.


Understanding the significance and functionality of Magenta, Mach, and Meter (M) on the Airbus A320 is essential for pilots operating this aircraft. Magenta simplifies navigation, providing a visual representation of the planned flight path. The Mach indicator assists pilots in maintaining a suitable speed relative to the speed of sound, ensuring safe and efficient flight. The altitude meter enables pilots to monitor and control the aircraft’s height accurately, ensuring compliance with assigned altitudes and avoiding potential conflicts.

These indicators and measurements play a crucial role in enhancing flight safety and efficiency on the Airbus A320. Pilots rely on them to make precise navigation decisions, maintain optimal speeds, and ensure accurate altitude management. By mastering the use of Magenta, Mach, and Meter, pilots can maximize the aircraft’s performance while prioritizing the safety of all onboard.

For More: What is LNAV on Airbus A320? (Lateral Navigation)