Plain English Meaning

Things that go wrong in flight at night. They are treated as their own category because the dark makes everything harder — you cannot easily see the ground, judge distances, or pick out a safe place to land.

Full Definition

In-flight problems or abnormal situations that occur during night flying, where reduced visibility, limited visual references, and impaired depth perception complicate the pilot's ability to identify the problem, locate suitable terrain, and execute a safe response. Common night emergencies include engine failure, electrical failures, loss of cockpit or instrument lighting, disorientation, and inadvertent flight into deteriorating .