What is the primary reason for filing an alternate airport for arrival?

Filing an alternate airport for arrival is primarily about ensuring that there are options available in case of adverse weather conditions at the intended destination. This practice is crucial for maintaining safety and operational efficiency in aviation. Adverse weather can include low visibility, strong winds, or storms that may affect the approach and landing at the primary airport. By designating an alternate airport, pilots and flight planners create a contingency plan that allows for a safe landing even if the primary destination becomes untenable due to unexpected weather changes.

The importance of having backup options can not be overstated, as it allows crews to quickly adapt to changing environmental conditions, thus minimizing the risk of diverting into unsafe situations. This proactive approach enhances the overall safety of the flight, ensuring that pilots and air traffic controllers can always operate within safe confines. The other options, while relevant to flight operations, do not pinpoint the core reason for filing an alternate airport in the context of unpredictable weather challenges.