Search results
Results from the WOW.Com Content Network
Blade pitch acts much like the gearing of the final drive of a car. Low pitch yields good low speed acceleration (and climb rate in an aircraft) while high pitch optimizes high speed performance and fuel economy. It is quite common for an aircraft to be designed with a variable-pitch propeller, to give maximum thrust over a larger speed range ...
A 6-bladed Hamilton Standard 568F propeller on an ATR 72 short-haul airliner. Lowry [27] quotes a propeller efficiency of about 73.5% at cruise for a Cessna 172.This is derived from his "Bootstrap approach" for analyzing the performance of light general aviation aircraft using fixed pitch or constant speed propellers.
Wallace Rupert Turnbull of Saint John, New Brunswick, Canada is credited in Canada for creating the first variable pitch propeller in 1918. [5] The French aircraft firm Levasseur displayed a variable-pitch propeller at the 1921 Paris Air Show. The firm claimed that the French government had tested the device in a ten-hour run and that it could ...
Aircraft flight mechanics are relevant to fixed wing (gliders, aeroplanes) and rotary wing (helicopters) aircraft. An aeroplane ( airplane in US usage), is defined in ICAO Document 9110 as, "a power-driven heavier than air aircraft, deriving its lift chiefly from aerodynamic reactions on surface which remain fixed under given conditions of flight".
For premium support please call: 800-290-4726 more ways to reach us
In adjustable-pitch propeller control system, the pilot has to adjust the propeller pitch angle and thus angle of attack of the propeller blades (typically with a lever) to achieve the desired propeller rotational speed. The increased pitch (blade angle of attack) increases the load on the engine and therefore slows it down, and vice versa.
Lightly loaded propellers for light aircraft and human-powered boats mostly have two blades, motor boats mostly have three blades. The blades are attached to a boss (hub), and while it can be a big boss, it should be as small as the needs of strength allow – with fixed-pitch propellers the blades and boss are usually a single casting.
Ground-adjustable propellers, which are mostly used on light and very light aircraft, are much cheaper and lighter than more sophisticated and versatile in-flight-adjustable propellers. A ground-adjustable propeller allows pitch changes to be made, although not in flight, to optimise the aircraft for current payload and flying conditions. [2]