Instrument Ground 2025 – 400 Free Practice Questions to Pass the Exam

For a pilot to determine whether they can penetrate the obstacle identification surfaces (OIS) for an Instrument Landing System (ILS) runway equipped with Medium Intensity Approach Lighting with Sequence Flashing (MALSR), the requirement regarding published visibility is crucial.

If the published visibility for the ILS approach is no lower than 3/4 statute miles, it indicates that, under these visibility conditions, the pilot is permitted to descend through the OIS safely. The OIS is designed to protect the approach path from obstructions, and specific visibility criteria have been established to ensure that pilots can effectively maneuver and identify the runway without encountering obstacles.

In this context, published visibility reflects established safety parameters that allow pilots to assess their approach against the standards necessary for a safe landing under various weather conditions. This is based on the understanding that when visibility falls below certain thresholds, it becomes more difficult to safely navigate and ensure adequate clearance from obstacles. Therefore, meeting the visibility requirement is essential for safe operation in these circumstances.