What is an LDA?

• A. Localizer Type Directional Aid; Similar to a localizer, but not part of an ILS. More precise than an SDF
• B. Localizer Direct Approach; Always part of an ILS
• C. Local Directional Antenna; Used for VOR alignment
• D. Lateral Directional Alignment; Non-precision approach aid

Answer: (A)

An LDA is a Localizer Type Directional Aid, a navigation facility that provides lateral guidance similar to a localizer but is not part of an ILS. It’s used when the final approach course is offset from the runway centerline, offering a precise lateral path without being tied to the ILS system. While a standard LDA typically provides only lateral guidance (no published glide slope), it often delivers a more precise course than an SDF, making it a more reliable desk-to-runway alignment for pilots. The other options use terms that aren’t standard for this facility, and they don’t describe the localizer-like, non-ILS nature of an LDA.