What is ALT HOLD in Aviation? (Altitude Hold Mode)

Altitude hold mode, also known as ALT hold, is a flight control mode commonly used in aviation. It is a feature found in many modern aircraft and autopilot systems, allowing the pilot to set and maintain a specific altitude during flight. This mode is particularly useful during long flights to reduce pilot workload and ensure accurate altitude control. In this article, we will explore the functionalities and benefits of altitude hold mode in aviation.

How does Altitude hold mode work?

Altitude hold mode operates by utilizing the aircraft’s autopilot or flight management system (FMS). When engaged, the altitude hold mode uses various sensors, such as the altitude sensor or barometric pressure sensor, to measure the aircraft’s current altitude. The pilot can then input the desired altitude into the system.

Once the altitude hold mode is activated, the system takes control of the aircraft’s pitch control surfaces, such as the elevators, to adjust the aircraft’s pitch and maintain the set altitude. If the aircraft starts to deviate from the set altitude, the system automatically adjusts the pitch to bring the aircraft back to the desired altitude.

It is important to note that altitude hold mode does not control the aircraft’s vertical speed. Instead, it maintains the selected altitude by adjusting the aircraft’s pitch angle. If the pilot desires a specific vertical speed, they would need to engage the vertical speed mode in addition to altitude hold mode.

Benefits of Altitude hold mode

Altitude hold mode offers several benefits to pilots and aircraft operators, including:

1. Reduced pilot workload

By utilizing altitude hold mode, pilots can reduce their workload during long flights. The system takes care of maintaining the set altitude, allowing pilots to focus on other critical tasks, such as navigation, communication, and monitoring of the flight.

Furthermore, altitude hold mode can be particularly beneficial during challenging weather conditions, where pilots may need to concentrate on flying the aircraft safely. By reducing the need to manually adjust the aircraft’s pitch to maintain altitude, pilots can have better control over the aircraft and make informed decisions.

2. Precise altitude control

Altitude hold mode ensures precise altitude control, minimizing altitude deviations during flight. The system continuously monitors the aircraft’s altitude and makes necessary adjustments to maintain the set altitude.

This precise altitude control is especially crucial during instrument flight rules (IFR) operations, where adherence to assigned altitudes is essential for air traffic control coordination. Altitude hold mode allows pilots to maintain a stable altitude without continuous manual corrections, reducing the risk of altitude deviations.

3. Fuel efficiency

Another advantage of altitude hold mode is improved fuel efficiency. By maintaining a steady altitude, the aircraft can fly at the most optimal altitude for fuel consumption, reducing fuel burn and operating costs.

When using altitude hold mode, the aircraft tends to be more stable, minimizing vertical speed variations that can result in inefficient fuel consumption. This stability allows for a smoother ascent or descent, optimizing the aircraft’s performance.

Furthermore, altitude hold mode can assist in maintaining optimal altitude during step climbs or step descents, which are performed to take advantage of changing atmospheric conditions and optimize fuel efficiency.


Altitude hold mode, also referred to as ALT hold, is an essential feature in aviation that allows pilots to set and maintain a specific altitude during flight. By utilizing autopilot systems and various sensors, the mode ensures precise altitude control, reduces pilot workload, and improves fuel efficiency.

Whether flying in challenging weather conditions or adhering to assigned altitudes during IFR operations, altitude hold mode provides pilots with the necessary tools to maintain accurate altitude control and enhance flight safety. This mode continues to be an integral part of modern aircraft systems, benefiting both pilots and aircraft operators.

For More: What is MTBSV in Aviation? (Mean Time Between Shop Visit)