What is HDG SEL on Boeing 737? (Heading Select)

When it comes to aviation, precision and accuracy are of utmost importance. Pilots rely on various instruments and systems to navigate the aircraft and ensure the safety of the passengers. The Boeing 737, one of the most popular commercial aircraft in the world, incorporates advanced navigation features to assist pilots in their tasks. One such feature is the Heading Select (HDG SEL) function. In this article, we will explore what Heading Select is, how it works, and its significance in the operations of the Boeing 737.

How Heading Select Works

The Heading Select function on the Boeing 737 allows pilots to precisely set and maintain a specific heading for the aircraft. It is a mode within the autopilot system that enables the pilot to select a desired heading, and the aircraft will automatically adjust its course to maintain that heading. This feature is particularly valuable during enroute navigation and approach phases of flight.

Once the Heading Select mode is engaged, pilots can input the desired heading using the Flight Management System (FMS) or the autopilot control panel. The autopilot system then takes control of the aircraft’s control surfaces to adjust the heading and keep it aligned with the pilot’s input. This relieves the pilot of continuously monitoring and manually adjusting the heading, allowing them to focus on other critical tasks.

The Heading Select function is especially useful in situations where the pilot needs to maintain a specific heading for navigational purposes, avoiding restricted airspace, or flying along established airway routes. It provides a reliable and accurate means of controlling the aircraft’s direction, ensuring precise and efficient navigation.

Significance of Heading Select on Boeing 737

The Heading Select feature plays a crucial role in ensuring the safe and efficient operation of the Boeing 737. Here are some key reasons why it is significant:

1. Precision Navigation

Pilots rely on the Heading Select function to navigate through varying weather conditions, airspace restrictions, and complex airway networks. By accurately maintaining a specific heading, the aircraft can follow a predefined route with precision, ensuring smooth and efficient operations. This feature is particularly important during instrument flight, where precise navigation is essential.

For example, during an instrument approach, the pilot can use Heading Select to align the aircraft with the designated final approach course, ensuring a stable approach and safe landing. Additionally, when flying in areas with high terrain or congested airspace, the Heading Select function allows pilots to maneuver the aircraft along specified routes, ensuring safe separation from other aircraft.

2. Reduced Pilot Workload

By automating the task of maintaining a specific heading, the Heading Select function reduces the pilot workload during critical phases of flight. The autopilot system takes care of the precise heading adjustments, allowing pilots to focus on other critical tasks, such as communication with air traffic control, monitoring systems, and managing emergencies.

This feature is particularly useful during long-haul flights when pilots need to maintain a specific course for extended periods. Rather than manually making constant adjustments, pilots can rely on the Heading Select function to ensure the aircraft stays on the desired heading. This helps to reduce fatigue and improve overall situational awareness.

3. Integration with Autopilot System

The Heading Select function seamlessly integrates with the autopilot system on the Boeing 737, offering a comprehensive and efficient navigation solution. It works alongside other autopilot modes, such as altitude hold, vertical speed, and lateral navigation, to provide a complete automation package for the flight crew.

During operations, pilots can easily engage and disengage the Heading Select mode via dedicated buttons on the autopilot control panel, ensuring quick and intuitive control over the aircraft’s heading. This integration allows for a smooth transition between various autopilot modes and empowers pilots with the flexibility to adapt to changing flight conditions.

Overall, the Heading Select function on the Boeing 737 enhances the aircraft’s navigation capabilities, reduces pilot workload, and ensures precise heading control. Its integration with the autopilot system contributes to the overall safety and efficiency of the aircraft’s operations.


The Heading Select function is a critical component of the Boeing 737’s advanced navigation system. By offering precise heading control and integration with the autopilot system, it enhances the aircraft’s navigational capabilities, reduces pilot workload, and ensures accurate flight operations. Pilots can confidently rely on this feature during enroute navigation and approach phases, allowing for safer and more efficient flights. The Heading Select function exemplifies the Boeing 737’s commitment to innovation and the continuous improvement of aviation technology.

For More: What is STAR on Boeing 737? (Standard Terminal Arrival Route)