Is it permissible to conduct an ILS approach at an alternate airport if the weather is below 600 feet and 2 miles?

The correct answer is that conducting an ILS approach at an alternate airport is permissible if the ILS is operational. This is rooted in regulations and guidelines that allow pilots to use certain instrument approaches, like the ILS, to conduct approaches to a lower minimum when the equipment is available and functional.

Specifically, even if the weather conditions at the alternate airport are below the standard minimums of 600 feet and 2 miles, as long as the ILS is operational and the approach is approved, the pilot can legally proceed. The rationale is that the precision of the Instrument Landing System provides more reliable guidance than non-precision approaches, which enables safe landings in lower visibility conditions.

The other options do not accurately reflect the regulations surrounding instrument approaches. For instance, stating that it is not permitted outright does not consider the operational status of the ILS. Saying it is permissible under any circumstance neglects the fact that operational status must be confirmed. Lastly, suggesting that special authorization is required would imply a need for a waiver beyond the normal regulations, which is not the case when the correct approach procedures are followed.