What differentiates an LDA from a localizer?

The ability of an LDA (Localized Directional Aid) to have straight-in minimums is conditional on the degree of offset from the centerline of the runway. Specifically, the offset must be less than 30 degrees for the LDA to qualify for straight-in minimums. This technical detail is crucial because it highlights the operational considerations pilots must account for when utilizing an LDA approach. If the offset exceeds 30 degrees, then the approach may only offer circling minimums, which requires more complex navigation and increased decision-making for pilots.

The other options present inaccuracies regarding the nature of LDAs. For example, an LDA is not aligned perfectly with the runway. Instead, it is designed to provide lateral guidance for approaches that may come in at an angle to the runway. LDAs also utilize traditional navigation aids and are not exclusively reliant on GPS systems. Furthermore, they are not restricted to visual approaches; instead, they are used for precision approaches when aligned appropriately for instrument flying.