How does an LDA differ from a standard ILS approach facility?

The Lateral Area Navigation (LDA) is designed to guide aircraft during the landing phase similarly to an Instrument Landing System (ILS), but its key distinction lies in the alignment of the localizer. In an LDA approach, the localizer is intentionally offset from the runway centerline. This means that unlike a standard ILS where the localizer is perfectly aligned with the runway, the LDA's localizer may be set up to provide guidance for runways that cannot be directly aligned due to obstacles or airspace restrictions.

This offset allows for flexibility in approach design, accommodating various terrains and surrounding structures while still providing necessary lateral guidance to pilots. Although the glide slope and approach angle may differ between LDA and ILS, it’s the offset localizer characteristic that defines the main distinction between the two systems.