Trim tabs
From Wikipedia, the free encyclopedia
Trim tabs are used in aircraft to relieve pressure on the stick or yoke thereby decreasing pilot workload. The most common example of a trim tab is the elevator trim found in almost all aircraft. In a constant climb, or descent, the elevator trim tab is adjusted to maintain the angle of attack without pilot interaction. Relieving this force allows the pilot to focus on other tasks such as traffic avoidance.
The rudder can also be trimmed with the rudder trim. In situations where constant rudder input is needed the pilot can move the tab on the rudder to compensate for pilot pressure. Therefore, in a long ascent which requires constant right rudder pressure, the pilot no longer has to maintain the rudder input manually.
Also, the ailerons can be trimmed. Rudder trim is less common, and aileron trim is found only on large fixed-wing aircraft (two engine and larger).
Not only does keeping an aircraft trimmed properly reduce pilot workload,it also increases fuel efficiency by reducing drag. For example, if an aircraft is climbing it will have a tendency to yaw which increases parasite drag because the craft is not flying straight into the flight path but at a slight angle which puts more of the fuselage into the wind.
The term "trim tab" was also popularized by R. Buckminster Fuller as a descriptive noun, as in "just call me trim tab." This use of the word denotes a person who seeks to achieve major social change with minimum effort (or drama) by careful selection of where, when, why and how to act to intervene. In this metaphorical use of the term, the person becomes the trim tab regulating the direction of the cultural drift.
