What is the primary purpose of the Instrument Landing System during an approach?

• A. Weather data to pilots
• B. Provide precise lateral and vertical guidance to align with the runway for landing
• C. Provide flight plan data
• D. Provide fuel calculations

Answer: (B)

An instrument landing system is designed to guide an aircraft along a precise path to the runway, even when pilots can’t rely on visual cues. The localizer gives you accurate horizontal guidance to stay on the runway centerline, while the glide slope provides precise vertical guidance to follow the correct descent path to the threshold. Together, they ensure you are properly aligned with the runway and on a safe descent profile for landing, which is essential in instrument meteorological conditions. The other options don’t involve the ILS: weather data, flight plan data, and fuel calculations are separate functions outside what the ILS provides.