controllable-pitch propeller

controllable-pitch propeller

[kən¦trōl·ə·bəl ′pich prə′pel·ər]
(mechanical engineering)
An aircraft or ship propeller in which the pitch of the blades can be changed while the propeller is in motion; five types used for aircraft are two-position, variable-pitch, constant-speed, feathering, and reversible-pitch. Abbreviated CP propeller.

controllable-pitch propeller

A propeller whose pitch can be altered by the pilot in flight. Unlike in a constant-speed propeller, where the governor automatically controls the pitch, here the pilot carries out the pitch adjustments. Takeoff is made with a low blade angle, so that the engine develops maximum power. The blade angle is increased during cruise, so that the engine operates at a slower and more economical speed.
References in periodicals archive ?
As discussed in our June 2018 issue, the FAA earlier this year changed its policy to no longer require a complex airplane--one with controllable-pitch propeller, flaps and retractable landing gear--for the commercial pilot-airplane or flight instructor-airplane certificates.
The company won the Collier Trophy in 1933 for a controllable-pitch propeller patented in 1927.
Less than a month after the April 4, 2018, fatal crash of a Piper Arrow during a commercial-pilot checkride, the FAA has changed its policy to no longer require a complex airplane (one with controllable-pitch propeller, flaps and retractable landing gear) for the commercial pilot-airplane or flight instructor-airplane certificates.
For each vessel Wartsila will deliver a Wartsila 32 main engine, a reduction gearbox, a Lips controllable-pitch propeller and a Lips transverse tunnel thruster.
The other three tugs use controllable-pitch propellers with twin azimuthing drives.
The workshop will provide reconditioning services to owners and operators of marine engines, gearboxes, controllable-pitch propellers, thrusters and other ship equipment.
The propulsion engine output is transmitted via reduction gears with hydraulic clutches to the controllable-pitch propellers. The reduction gears have two ratios, one for high and one for low speeds.
In airplanes with controllable-pitch propellers, reducing propeller speed is an essential part of attaining best glide performance.
The vessels would each have a fully-redundant propulsion plant with two Wartsila 8L32 diesel engines, each driving Lips 4CF13 feathering controllable-pitch propellers through a Wartsila SCV95-P58 reduction gearbox.
Less apparent but still critical to maximum performance are things like good rudder coordination, retracting cowl flaps ("cooling drag" from excess air flowing across cylinders and engine components greatly increase drag) and--very important--propeller speed with controllable-pitch propellers.
In airplanes with controllable-pitch propellers, know the expected manifold pressure and rpm at take-off power.