When is an alternate required during flight planning?

An alternate airport is required during flight planning to ensure the safety and efficiency of the flight. Each of the scenarios presented underscores circumstances where having an alternate is advisable.

When crosswinds are out of limits, it indicates potentially unsafe landing conditions at the destination airport, making it prudent to have an alternate available to divert if necessary.

Similarly, if radar is required for navigation or approach, which could be due to inadequate visual references or complex airspace, an alternate is important to ensure that the aircraft can safely land elsewhere if conditions at the destination deteriorate.

Forecasts that include severe thunderstorms significantly heighten the risk of severe weather conditions impacting the approach and landing phases. In such instances, having an alternate provides a contingency plan for avoiding hazardous weather.

Thus, the requirement of an alternate is linked to multiple safety precautions in the face of various operational challenges, which is why all these factors contribute to the necessity of planning for an alternate airport.