Definition
The angle, measured in degrees, between the aircraft's heading and the desired course, applied into the wind to keep the aircraft tracking along that course. It offsets the sideways push of the wind so that the actual ground track matches the intended course.
Plain English
The amount you point the nose into the wind so that, even though the wind is blowing you sideways, you still travel along the line you want.
Context Anchor
Used when tracking a navigation course, such as a VOR course, and correcting for wind while keeping the aircraft on the intended line over the ground.
Derivation
Drift comes from the Old English drīfan, meaning 'to be carried along.' In flying, drift is the sideways movement of the aircraft caused by wind. The 'correction angle' is simply the amount you turn the nose to cancel that drift.
Why Pilots Care
Applying the correct drift correction angle keeps the aircraft on the planned route, avoiding navigation errors and airspace deviations.
Analogy
Think of walking across a moving walkway sideways. To reach a point straight ahead, you have to angle your steps slightly into the direction of motion. The amount you angle is the drift correction.
Grounding Statement
If wind is pushing the aircraft left of course, the pilot points the nose slightly right so the path over the ground remains straight along the course.
Intuition Check
Do not think of drift correction angle as the amount the aircraft is already off course. It is the intentional angle you hold into the wind to prevent or stop that sideways drift.
Example Sentence 1
With a strong crosswind from the left, the pilot applied a 10-degree drift correction angle to the left to stay on the desired course.
Example Sentence 2
With a strong crosswind, a larger drift correction angle was needed to stay on the airway centerline.