What does a flashing red light indicate when in the air?

A flashing red light while in the air is a signal indicating that the airport is unsafe for landing. This signal typically warns pilots to avoid landing because of conditions that may jeopardize safety, such as poor weather, an obstructed runway, or other hazards that could pose a risk to incoming aircraft. When pilots see this signal, it is crucial to take it seriously and either circle until the situation improves or divert to another airport, ensuring that safety is the top priority.

Understanding the context of the other signals can provide clarity. For instance, a steady green light usually means that it is clear to land, while a flashing green light indicates that the pilot should return for landing. Clear for takeoff is usually denoted by a steady green light. Recognizing these signals is vital for maintaining safety and situational awareness while flying.