What is LIS on Airbus A320? (Localizer Internal Smoothing)

Localizer Internal Smoothing (LIS) is an important feature of the Airbus A320 aircraft’s navigation system that helps improve the precision of the localizer signal. The localizer is a crucial component of the Instrument Landing System (ILS) and is responsible for providing lateral guidance to the aircraft during the final approach phase of landing. By using advanced algorithms and data processing techniques, LIS helps to minimize the small errors and variations in the localizer signal, ensuring a smoother and more accurate navigation experience for the pilots.

Let’s take a closer look at how Localizer Internal Smoothing works and why it is an essential feature of the Airbus A320.

The Functionality of Localizer Internal Smoothing

The Localizer Internal Smoothing (LIS) feature utilizes a combination of techniques to enhance the localizer signal quality. It works by continuously analyzing the incoming localizer signal and applying various algorithms to minimize any fluctuations or inconsistencies. This ensures a more reliable and stable signal, reducing the likelihood of abrupt course corrections during the final approach phase.

One of the primary functions of LIS is to reduce the effect of small changes in the localizer signal caused by atmospheric conditions and other external factors. These small fluctuations, known as “needle vibrations,” can introduce unwanted variations in the displayed course deviation on the aircraft’s navigation display. By employing advanced smoothing algorithms, LIS filters out these minor disturbances, providing a more accurate representation of the aircraft’s lateral position.

In addition to minimizing needle vibrations, LIS also helps reduce the impact of localizer signal errors resulting from the installation and alignment of the localizer antenna array. The alignment of the localizer antennas can introduce minor angular errors, which may affect the accuracy of the localizer signal. Localizer Internal Smoothing compensates for these errors by applying corrective measures, ensuring that the displayed course deviation remains reliable and precise.

The Benefits of Localizer Internal Smoothing

Localizer Internal Smoothing (LIS) offers several benefits to pilots and aircraft operators:

Enhanced Accuracy: By minimizing needle vibrations and compensating for localizer signal errors, LIS ensures a higher degree of accuracy in the displayed course deviation. This allows pilots to maintain a more precise lateral track during the final approach phase, improving landing safety and efficiency.

Smooth Navigation: The advanced smoothing algorithms of LIS help eliminate sudden course corrections caused by minor fluctuations in the localizer signal. This provides a smoother and more predictable navigation experience for the pilots, reducing workload and enhancing situational awareness.

Improved Reliability: By filtering out unwanted signal variations, LIS enhances the reliability of the localizer signal. This ensures that pilots receive accurate and consistent guidance information during critical stages of flight, reducing the risk of navigational errors and enhancing operational safety.

Incorporating Localizer Internal Smoothing into the Airbus A320 navigation system demonstrates the commitment of Airbus to continuous improvement and innovation. This feature showcases the company’s dedication to providing pilots with advanced tools and technologies that enhance the overall flight experience.

For More: What is WTB on Airbus A320? (Wing Tip Brake)