What is THSHD on Boeing 777? (Threshold)

Threshold, abbreviated as THSHD, is an important term in aviation and refers to a specific point on a runway where the aircraft initiates its landing. In the context of Boeing 777 aircraft, the threshold indicates the precise starting point of the runway where the pilot aims to touch down during a landing maneuver. Understanding the concept of the threshold and its significance is vital for pilots, air traffic controllers, and aviation enthusiasts as it plays a crucial role in ensuring safe and efficient operations.

Importance of Threshold on Boeing 777

The threshold on a Boeing 777 holds immense importance for both pilots and air traffic controllers. It serves as a reference point for pilots during landing and helps them to accurately judge the aircraft’s approach and touchdown point. Additionally, the threshold assists in maintaining a standardized and consistent approach for all aircraft using the runway, which is crucial for maintaining safety and preventing collisions.

During the landing phase, the pilot aims to touch down as close to the threshold as possible, maximizing the available runway length and minimizing the distance required for deceleration. This is particularly crucial in challenging landing conditions such as adverse weather or short runways. The threshold helps pilots determine the correct approach path and landing configuration, allowing them to execute a safe and efficient landing.

Furthermore, air traffic controllers also rely on the threshold as a reference point for providing accurate instructions to pilots. They use the position of the threshold to guide aircraft during the final approach and landing, ensuring proper separation between arriving and departing aircraft. By coordinating with pilots and monitoring their approach to the threshold, air traffic controllers maintain a safe flow of traffic and prevent congestion on the runway.

Factors Affecting the Threshold on Boeing 777

The position of the threshold on a Boeing 777 runway is determined by several factors, including runway length, aircraft performance, and environmental conditions. Let’s explore these factors in more detail:

Runway Length

The length of the runway plays a significant role in determining the position of the threshold on a Boeing 777. Longer runways provide pilots with more flexibility in choosing their touchdown point, allowing for ample runway space to safely decelerate the aircraft. On the other hand, shorter runways may require pilots to touch down closer to the threshold, ensuring they have enough runway left for stopping the aircraft within the available distance.

For example, if a Boeing 777 is operating on a shorter runway with a limited length, the pilot may need to initiate the landing closer to the threshold to ensure they have enough room to stop the aircraft safely. This requires precise calculations and judgment to perform a successful landing within the available space.

Environmental Conditions

Environmental conditions, such as wind direction and speed, also influence the choice of the threshold on a Boeing 777 aircraft. Pilots consider wind conditions to determine the most suitable approach and landing strategy. They aim to land the aircraft into the wind, which helps increase aerodynamic control, reduce groundspeed, and minimize the distance required for deceleration.

In crosswind situations, pilots may need to adjust their approach and touchdown point to compensate for the sideways drift caused by the wind. By considering the environmental conditions, pilots can select the most optimal threshold position to ensure a safe and stable landing.


The threshold holds great significance in the operations of a Boeing 777 aircraft during landing. It serves as a point of reference for pilots and air traffic controllers, enabling precise approach and safe touchdown. Factors such as runway length and environmental conditions impact the selection of the threshold, with pilots making calculated decisions to ensure a successful landing within the available parameters.

Understanding the importance of the threshold on a Boeing 777 provides valuable insights into the intricacies of aircraft operations and the meticulous planning involved in every landing maneuver. By considering the factors affecting the threshold, pilots can execute their landings with precision, enhancing safety and operational efficiency in the aviation industry.

For More: What is RNAV on Boeing 777? (Area Navigation)