Plain English Meaning

Yawning over and over again, not just once or twice. When it keeps happening, it is a signal the body is tired and starting to lose sharpness.

Full Definition

A recognized warning sign of fatigue in which a pilot yawns repeatedly and frequently over a sustained period, indicating that the body is struggling to maintain alertness and oxygen intake during a task that requires focused attention.

Context Anchor

Seen in fatigue discussions, preflight self-checks, and instructor observations of a student’s readiness to learn or fly safely.

Derivation

‘Persistent’ comes from the Latin persistere, meaning ‘to stand firm’ or ‘keep going.’ Here it points to yawning that keeps returning rather than a single yawn. The emphasis is on the pattern, not the act itself.