Definition
A noticeable decline in the precision with which a pilot operates the aircraft's controls, typically shown by sloppy heading, altitude, and airspeed control, rough or delayed inputs, and poor coordination. It is one of the recognized warning signs of fatigue.
Plain English
The pilot's flying gets less precise. Headings drift, altitudes wander, and control inputs become rough or late. Things that were easy to hold steady suddenly aren't.
Context Anchor
Seen in fatigue discussions, especially when an instructor or pilot is watching for signs that tiredness is affecting aircraft handling.
Derivation
Degradation comes from the Latin gradus, meaning 'step,' so to degrade is literally to step down. Here it describes a step down in how accurately the pilot controls the aircraft.
Why Pilots Care
It is often the first visible sign that fatigue, stress, or distraction is affecting performance. Catching it early is a chance to break off the task, rest, or hand over before a small loss of precision becomes a safety issue.
Analogy
It is like writing your signature when you are very tired. You can still write, but the letters may be less smooth and less accurate than usual.
Intuition Check
Do not read this as a mechanical problem with the aircraft controls. Here, the controls may be working normally; the pilot’s precision in using them is getting worse.
Example Sentence 1
After four hours of training in turbulence, the instructor noted a degradation of control accuracy and ended the lesson early.
Example Sentence 2
Early signs of fatigue often appear as degradation of control accuracy during the final approach phase.