The STL LDA/GA approach is classified as which type of approach?

• A. Non-precision
• B. Precision
• C. Glide slope required
• D. Circling-only

Answer: (A)

In instrument procedures, precision approaches provide both accurate lateral and vertical guidance with a published decision altitude, while non-precision approaches offer lateral guidance (and sometimes advisory vertical cues) but do not meet precision standards. An LDA is a localizer-type approach that supplies lateral guidance, but its path does not meet the stringent requirements of a true precision approach.

The LDA/GA variant adds a Glidepath Advisory, giving you an indication of descent along a glidepath, but this vertical guidance is advisory rather than a published, certified glide slope. Because the vertical guidance isn’t as exact or validated as a true glide slope, and the approach is based on the localizer with an offset alignment, it is classified as non-precision.

If it were a true glide slope with precise vertical guidance and the necessary certifications, it would be a precision approach. If the path required circling-only due to offset alignment or minima restrictions, that would be a separate situation and not the basis for calling it precision.