Which factor is essential when evaluating whether an alternate airport is viable?

• A. The altitude at which to fly the alternate.
• B. The color of the airport signage.
• C. Forecast conditions at the alternate and the availability of appropriate approach procedures.
• D. Number of airlines operating.

Answer: (C)

When deciding whether an alternate airport is viable, the key issue is that you must be able to land there safely if you divert. That means two main factors: the forecast conditions at the alternate on your ETA and whether there are usable instrument approach procedures you can actually fly for that airport. If the weather at the alternate is forecast to be above minimums and there are published approaches appropriate for your aircraft, you have a realistic option to land there. Without favorable forecast conditions or without workable approaches, the alternate isn’t a viable backup.

The other ideas aren’t determining factors. The altitude you plan to fly to reach the alternate is part of routing decisions but doesn’t by itself determine viability. The color of airport signage is not relevant to landing capabilities. The number of airlines operating at the airport has no bearing on whether you can land there under IFR.