coefficient A

coefficient A

[¦kō·ə′fish·ənt ′ā]
(navigation)
A component of magnetic compass deviation of constant value with compass heading, resulting from mistakes in calculations, compass and pelorus misalignment, and unsymmetrical arrangements of horizontal soft iron.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

coefficient A

The coefficient of constant compass deviation caused by misplacement of the lubber line of a compass in relation to the longitudinal axis of the carrying aircraft. This misplacement results in a constant error for all headings of the airplane. Coefficient A is the mean value of the deviations on all cardinal and quadrantal headings. Coefficient A = 1/8(Deviation on magnetic North + South + East + West + Northeast + Northwest + Southeast + Southwest).
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved