What is a provisional airport?

A provisional airport is designated as a facility approved for use by air carriers when the regular airport is unavailable, typically due to circumstances like severe weather, maintenance issues, or any scenario that temporarily limits operations at the primary airport. This type of airport provides an alternative for airlines, ensuring that flight operations can continue with minimal disruption to passengers and cargo transport.

The concept is crucial for the continuity of air services, allowing airlines to adapt to unexpected changes in airport availability. Understanding the function of a provisional airport, especially in terms of regulatory approval and operational procedures during irregular conditions, is essential for any aircraft dispatcher.

The other options describe scenarios related to airports, but they do not accurately capture the definition of a provisional airport. For instance, a backup airport under normal conditions refers more to strategic planning than to the specific regulatory approval for alternate airport use during unforeseen circumstances.