Inside the ILS Outer Marker or the fix used in lieu of the OM, do not authorize vehicles/aircraft to operate in the ILS critical area when conditions are a reported ceiling ? feet or visibility ? miles. Which combination is correct?

Inside the ILS Outer Marker or the fix used in lieu of the OM, do not authorize vehicles/aircraft to operate in the ILS critical area when conditions are a reported ceiling ? feet or visibility ? miles. Which combination is correct?

• A. Ceiling less than 800 feet; visibility less than 2 miles
• B. Ceiling less than 1000 feet; visibility less than 3 miles
• C. Ceiling less than 600 feet; visibility less than 1 mile
• D. Ceiling less than 900 feet; visibility less than 2.5 miles

Answer: (C)

The situation tests how strict the protection is for the ILS critical area when you’re near the Outer Marker or its substitute. The ILS critical area must be kept clear to prevent any signal interference or dangerous incursions by vehicles or other aircraft that could compromise the localizer and glideslope guidance on an instrument approach. When weather deteriorates to a point where visibility or ceiling is too low, the risk of misinterpreting signals or not seeing an approaching aircraft increases, so operations inside that protected zone are restricted. The correct thresholds state that you should not authorize entry into the ILS critical area if the ceiling is below 600 feet or the visibility is below 1 mile. This combination of numbers matches the mandated protection level for this scenario, reflecting a stricter limit to maintain safe operation as visibility and altitude become limiting factors. The other options use higher minima, which would not align with the required protection level for this particular case.

The situation tests how strict the protection is for the ILS critical area when you’re near the Outer Marker or its substitute. The ILS critical area must be kept clear to prevent any signal interference or dangerous incursions by vehicles or other aircraft that could compromise the localizer and glideslope guidance on an instrument approach. When weather deteriorates to a point where visibility or ceiling is too low, the risk of misinterpreting signals or not seeing an approaching aircraft increases, so operations inside that protected zone are restricted.

The correct thresholds state that you should not authorize entry into the ILS critical area if the ceiling is below 600 feet or the visibility is below 1 mile. This combination of numbers matches the mandated protection level for this scenario, reflecting a stricter limit to maintain safe operation as visibility and altitude become limiting factors. The other options use higher minima, which would not align with the required protection level for this particular case.