Autofeather

Engine feature

Autofeather is a feature of the engines on some turboprop and piston engine aircraft. When the power being produced by the engine drops to the point where it is not contributing to thrust, the propeller will go into a feathered mode to reduce drag.^[1]

The auto feather system also allows pilots to reduce the drag of the propellers during an engine failure, therefore, allowing the plane to glide for a longer period of time.

An automatic feathering system was first introduced on the Martin 4-0-4 aircraft, a piston engine airplane. The system was designed to automatically feather an engine that failed during takeoff or initial climb. It is not used during cruise.

References

^ Hitchens, Frank (11 May 2015). Propeller Aerodynamics: The History, Aerodynamics and Operation of Aircraft Propellers. Andrews UK Limited. ISBN 9781785381249. Retrieved 19 April 2023.

Aircraft piston engine components, systems and terminology

Piston engines

Mechanical components	Camshaft Connecting rod Crankpin Crankshaft Cylinder Cylinder head Gudgeon pin Hydraulic tappet Main bearing Obturator ring Oil pump Piston Piston ring Poppet valve Pushrod Rocker arm Sleeve valve Tappet
Electrical components	Alternator Capacitor discharge ignition Dual ignition Electronic fuel injection Generator Ignition system Magneto Spark plug Starter
Terminology	Air-cooled Aircraft engine starting Bore Compression ratio Dead centre Engine displacement Four-stroke engine Horsepower Ignition timing Manifold pressure Mean effective pressure Naturally aspirated Monosoupape Overhead camshaft Overhead valve engine Rotary engine Shock cooling Stroke Time between overhauls Two-stroke engine Valve timing Volumetric efficiency

Propellers

Components	Propeller governor Propeller speed reduction unit Spinner
Terminology	Autofeather Blade pitch Constant-speed Contra-rotating Counter-rotating Scimitar Single-blade Variable-pitch

Engine instruments

Engine controls

Fuel and induction
system

Other systems

Jet engines and aircraft gas turbines

Gas turbines
and jet propulsion

Types	Air turborocket Pulsejet/Gluhareff Pressure Jet Pulse detonation engine Propfan Turbofan Turbojet Turboprop Turboshaft Ramjet Rocket Rotating detonation engine
Mechanical components	Accessory drive Air intake Afterburner (reheat) Axial compressor Centrifugal compressor Combustor Constant speed drive Impeller Propelling nozzle Turbine blade
Principles	Aircraft engine starting Bleed air Brayton cycle Bypass ratio Compressor stall Engine pressure ratio (EPR) Flameout Jet engine performance Overall pressure ratio Propulsive efficiency Specific impulse Thrust Thrust lapse Thrust specific fuel consumption Thrust to weight ratio Variable cycle engine Windmill restart

Propellers

Components	Propeller governor Propeller speed reduction unit
Principles	Autofeather Blade pitch Constant-speed Contra-rotating Counter-rotating Proprotor Scimitar Variable-pitch