SAE ARP1217B

This SAE Aerospace Recommended Practice (ARP) provides guidance on the engine performance parameters that may be selected by airframe and engine manufacturers, and used by a pilot or operator, to monitor the thermodynamic health of a turboshaft engine installed in a rotorcraft and the measurement system accuracies desired. Different accuracies may be required for in-flight operations such as engine control. During the SAE Five-Year Review, it was identified that although ARP1217A’s scope states that it provides “the measurement parameters that may be used by a pilot or operator to monitor the thermodynamic health of a turboshaft engine,” the actual content seemed more oriented on providing guidance to the airframe or engine manufacturers for the selection of the parameters and instrumentation and for which the pilot or operator would have little to no impact as the product end user. In addition, it was found that relevant reference documents providing complementary information were not referenced in ARP1217A. Finally, instrumentation accuracy/uncertainty being something that evolves through the years, a thorough review was deemed required to make sure that ARP1217 is aligned with the current state/understanding of the respective technologies.