The term quadrant denotes the quarter-circle panel that houses the levers. The same word labels the throttle quadrant, or thrust-lever quadrant, on a flight deck where throttles are arranged along a circular arc and their visible profile forms a 90 degree sector of a complete circle.
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Jim Goodrich
Jim Goodrich is a pilot, aviation expert and founder of Tsunami Air.
What is a quadrant in aircraft?
A quadrant refers to the axes of a two-dimensional Cartesian system which divide the plane into four infinite regions, although the axes themselves are not part of the respective quadrants. The term quadrant originates from Latin ‘quadrans’ meaning fourth part. In aircraft, the term quadrant denotes the throttle quadrant or thrust lever quadrant, which is the circular arc in which the throttles are placed.
In aircraft terminology, the word quadrant carries three distinct but related meanings. First, it preserves its geometric root: a quadrant is a circular segment that covers 90 degrees, one fourth of a full circle, and this quarter-circle geometry is visible in every aeronautical application. Second, the throttle quadrant is the named area of the flight deck that houses the thrust levers. It is a panel with curved slots through which the levers travel through an arc of roughly 90 degrees, and it contains secondary controls like air-fuel mixture, propeller pitch, flap selectors, and thrust-reverse toggles. In large airliners the quadrant sits at the front of the center pedestal whereas in smaller general-aviation machines with side-by-side seating it is mounted low and centered on the instrument panel. Tandem-seat aircraft often place it on the left cabin wall. Third, cable quadrants are mechanical quadrants installed in the control run. These quadrants are quadrantal sectors through which steel cables are routed, translating cockpit inputs into movement of the rudder, ailerons, and elevators. They form the link between the pilots' controls and the control surfaces.
