SAE AIR 5020

The purpose and intent of Subcommittee E-33E’s effort, the reporting objectives, and the limitations inherent in the reported findings and recommendations are reviewed since these factors are the basis of the information contained in this document.

SAE E-33E Subcommittee was formed to assess the level of industry experience that exists in the area of thrust determination during aircraft time-variant operating conditions. A prime objective was to provide a center for gathering expertise and to be a forum for the exchange of ideas and viewpoints. The committee recognized that a practice for the rigorous treatment of time-dependent thrust did not exist and that several critical aspects of its accounting would need to be investigated.

The specific objectives of this document are: a. to examine aircraft and engine operating conditions under which the quasi-steady thrust assumption is valid; b. to determine the extent to which time-dependent (nonstationary) force accounting for engine net thrust and propulsion system throttle-dependent terms is required, consistent with existing and developing thrust-minus-drag techniques; c. to report time-dependent thrust methodologies and measurement techniques used for flight and ground testing; d. to present the results of a data review of state-of-the-art methodology appropriate to the determination of aircraft-installed thrust during quasi-steady and dynamic maneuvers; and e. to provide guidelines for validating and improving time-dependent thrust determination as appropriate to a specific program