During an ILS approach, what is the consequence of glide slope failure?

In the context of an Instrument Landing System (ILS) approach, the glide slope provides vertical guidance to help pilots achieve the correct descent path toward the runway. If the glide slope signal fails, the pilot can still rely on the localizer portion of the ILS for lateral guidance.

Selecting to continue the approach using the localizer Minimum Descent Altitude (MDA) is a valid option because it allows the pilot to complete the approach using horizontal guidance to align the aircraft with the runway. The localizer gives direction, while the MDA ensures that the aircraft maintains a safe altitude until it is visually confirmed that a landing can be safely executed. The pilot would typically have to monitor their altitude closely and be prepared for visual reference to ensure a safe landing procedure, especially in poor visibility conditions.

While there are other protocols to consider in case of glide slope failure, continuing the approach using the localizer MDA is a recognized procedure, hence making the choice of continuing with caution viable within the operational guidelines of ILS approaches.