The total thrust of a jet engine without deduction of the drag caused by the momentum of the incoming air (ram drag). This thrust is measured when the engine is static, or not moving. Gross thrust includes the thrust generated by the momentum of the outgoing gases and the thrust resulting from the differences between the static pressure at the nozzle and ambient pressure. The gross thrust is equal to the product of the mass rate of fluid flow and the velocity of the fluid relative to the nozzle, plus the product of the nozzle exit area and the difference between the exhaust pressure and ambient pressure.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved