This SAE Aerospace Information Report (AIR) presents a discussion of drag torques of engine accessories operating at cold temperature. Various conditions of temperature, speed, and acceleration rates are reviewed showing the merits of each method and recommending a standard test method.
The purpose of this Aerospace Information Report is to present a brief discussion of the drag torques caused by accessory units while starting under -65 ′ conditions. The various parameters affecting the magnitude of the drag torque at various speeds and accelerations rates are reviewed. In conclusion, this report establishes the difference in accessory drag torque characteristics that are obtained by various test procedures, and thereby this difference warrants the need for the establishment of a standard test method.
Changes in this revision are format/editorial only.