Propeller (aeronautics)

In <a href="/facts/Aeronautics/yu2YEPv9">aeronautics</a>, an aircraft propeller, also called an airscrew, converts rotary motion from an <a href="/facts/Aircraft_engine/XJo2Bd2e">engine</a> or other power source into a swirling <a href="/facts/Slipstream/hGTSYo0n">slipstream</a> which pushes the propeller forwards or backwards. It comprises a rotating power-driven hub, to which are attached several radial <a href="/facts/Airfoil/2d3l6hKd">airfoil</a>-section blades such that the whole assembly rotates about a longitudinal axis. The <a href="/facts/Blade_pitch/4cqYgsr4">blade pitch</a> may be fixed, manually variable to a few set positions, or of the automatically variable "constant-speed" type.
The propeller attaches to the power source's driveshaft either directly or through <a href="/facts/Propeller_speed_reduction_unit/AwTMb78T">reduction gearing</a>. Propellers can be made from wood, metal or <a href="/facts/Composite_material/UBysQldh">composite materials</a>.
Propellers are most suitable for use at subsonic airspeeds generally below about 480 mph (770 km/h), although supersonic speeds were achieved in the <a href="/facts/McDonnell_XF-88B/o7CBMAUg">McDonnell XF-88B</a> experimental propeller-equipped aircraft. Supersonic tip-speeds are used in some aircraft like the <a href="/facts/Tupolev_Tu-95/NT30UYG8">Tupolev Tu-95</a>, which can reach 575 mph (925 km/h).

Propeller (aeronautics) open-in-new

Propeller (aeronautics)