What is EXT on Boeing 737? (Extend)

The Boeing 737 aircraft is undoubtedly one of the most popular and widely used aircraft in the world. Known for its reliability, efficiency, and versatility, the 737 has become the backbone of many airlines’ fleets. In order to further enhance the capabilities and performance of this iconic aircraft, Boeing introduced a new feature called Extend, which stands for Enhanced Navigation System and Display System in 2003.

Extend is a revolutionary technology developed by Boeing to provide pilots with enhanced situational awareness and navigation capabilities. It consists of advanced avionics systems and displays that enable pilots to better track their position, navigate accurately, and make precise approaches and landings, even in challenging conditions.

With Extend, Boeing aimed to improve the overall efficiency and safety of the 737 aircraft by reducing crew workload and enhancing operational capabilities. This article will provide a detailed overview of Extend, its key features, and the benefits it offers to pilots and airlines.

The Key Features of Extend

Extend incorporates several advanced features and capabilities that make it an invaluable addition to the Boeing 737 aircraft. Let’s take a closer look at some of its key features:

The Flight Management System (FMS)

The Flight Management System (FMS) is a critical component of Extend. It is a computerized navigation system that uses a combination of sensors, databases, and algorithms to automatically calculate and display the aircraft’s optimal flight path. The FMS in Extend provides pilots with accurate navigation information, such as waypoints, airways, and approaches, enabling them to plan their flight routes more efficiently.

Moreover, the FMS enables pilots to input various parameters, such as wind direction and speed, aircraft weight, and performance data, to further optimize the aircraft’s flight path and fuel efficiency. By taking into account these factors, the FMS calculates the most economical flight profile, allowing airlines to reduce their operating costs and environmental footprint.

The Enhanced Vision System (EVS)

Another significant feature of Extend is the Enhanced Vision System (EVS). This advanced technology uses infrared sensors and cameras mounted on the aircraft to provide pilots with enhanced visibility, especially during low-visibility conditions, such as fog or heavy rain. The EVS displays real-time video images on the flight deck displays, allowing pilots to see the runway and surrounding environment more clearly.

The EVS greatly enhances situational awareness and enables pilots to make more informed decisions during critical phases of flight, such as takeoff and landing. It also increases the runway length available for landing, as pilots can identify the runway much earlier during low-visibility approaches. This feature significantly improves operational efficiency and safety, reducing the risk of runway incursions and accidents.

The Benefits of Extend

Extend offers a range of benefits to both pilots and airlines, contributing to increased safety, efficiency, and overall operational performance. Here are some of the key benefits:

Improved Situational Awareness

With Extend, pilots have access to comprehensive and accurate navigation information, enabling them to maintain better situational awareness throughout the flight. The advanced displays present a clear picture of the aircraft’s position relative to the flight plan, airspace boundaries, and potential hazards, facilitating better decision-making and reducing the risk of navigational errors.

Coupled with the Enhanced Vision System, pilots can also have a clearer view of the runway and surrounding environment, improving their situational awareness during critical phases of flight. This enhanced awareness enables pilots to respond effectively to unforeseen situations and ensures a higher level of safety for passengers and crew.

Increased Operational Efficiency

Extend significantly improves operational efficiency by optimizing flight profiles, reducing fuel consumption, and minimizing delays due to adverse weather conditions. The Flight Management System calculates the most fuel-efficient flight path, taking into account factors such as wind, temperature, and aircraft weight. This optimization results in reduced fuel costs and lower carbon emissions, benefiting both airlines and the environment.

The Enhanced Vision System also plays a crucial role in increasing operational efficiency. Pilots can land the aircraft in lower visibility conditions, minimizing the reliance on ground-based navigation aids and reducing the need for diversion or go-arounds. This ultimately leads to smoother operations, fewer delays, and increased passenger satisfaction.


Extend has proven to be an invaluable addition to the Boeing 737 aircraft, enhancing its navigational capabilities and improving the overall efficiency and safety of flights. With features like the Flight Management System and the Enhanced Vision System, pilots have access to advanced tools and displays that significantly improve situational awareness, navigation accuracy, and operational efficiency. This technology has undoubtedly contributed to the success and popularity of the Boeing 737, making it a preferred choice for airlines worldwide.

For more information about Boeing Extend, visit the official Boeing website here.

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