An increment in drag, resulting from the aerodynamic trimming of an aircraft. The tailplane in any aircraft produces lift, which may be positive or negative. In the process of producing lift, drag is also produced. If additional lift is required to trim longitudinal forces, then the drag produced is called trim drag. Its value is maximum when the aircraft is flying at low transonic speeds.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved