Plain English Meaning

Drifting off your chosen altitude or airspeed without meaning to. The numbers change while you're focused on something else, and you didn't catch it.

Full Definition

Unplanned departures from a target altitude or airspeed during flight, occurring when the pilot allows the aircraft to drift outside the intended values without recognizing or correcting the change in time.

Context Anchor

Seen in basic flight training when learning to hold a steady altitude and airspeed during climbs, descents, turns, and straight-and-level flight.