Feathered Propeller

A feathered propeller is one in which the blade pitch has been rotated so that the chord line is parallel to the direction of flight — reducing drag to an absolute minimum after an engine failure on a multi-engine aircraft. Feathering places the propeller blades edge-on to the airflow so the propeller is no longer windmilling and producing drag.

Why Feathering Matters

A windmilling (unfeathered) propeller on a failed engine produces enormous drag — as much as or more drag than all other aircraft components combined. This drag dramatically reduces single-engine climb performance. Feathering the propeller after an engine failure on a twin can be the difference between maintaining altitude and descending into terrain.

Feathering Procedure

After confirming which engine has failed (identify, verify, feather): identify the dead engine (foot off the dead engine — “dead foot, dead engine”), verify by slowly retarding the throttle of the suspect engine, then move the propeller control to feather. The sequence varies by aircraft type — follow the POH and memory items.

Windmill vs. Feather

A windmilling propeller: blades at low pitch, high RPM, generating drag. A feathered propeller: blades at ~90° pitch, zero or near-zero RPM, minimal drag. The improvement in single-engine performance after feathering is dramatic.

Related Terms

See also: Propeller, Critical Engine, Pitch Setting.