Definition
Rotating the blades of a variable-pitch propeller to an edge-on angle relative to the oncoming airflow so the blades produce minimal drag and the propeller stops rotating. Feathering is used when an engine is shut down or has failed in flight, primarily on multi-engine airplanes and certain single-engine aircraft equipped with feathering propellers.
Plain English
Turning the propeller blades sideways to the wind so they slice through the air instead of catching it. This stops the propeller from spinning and greatly reduces drag after an engine quits or is shut down.
Context Anchor
Seen in engine-out, glide, and power-off approach discussions, especially when comparing how much drag different propeller positions create.
Derivation
From the idea of turning a blade edge-on like a feather slicing through the air. A flat blade pushed broadside through the wind catches a lot of air; a feathered blade meets the wind with its thin edge and barely disturbs it.
Why Pilots Care
Reduces drag enough for the remaining engine to maintain airspeed and climb performance instead of being overwhelmed by a windmilling propeller.
Grounding Statement
With the blades turned edge-on, the propeller cuts through the air instead of being pushed around by it.
Intuition Check
Feathering does not mean making something lighter or softer. In this context, it means turning propeller blades to a low-drag angle relative to the airflow.
Example Sentence 1
After confirming the right engine had failed, the pilot feathered the propeller to reduce drag and maintain altitude on the remaining engine.
Example Sentence 2
During the power-off accuracy approach, the instructor called for feathering the propeller on the simulated failed engine to reduce drag.