This SAE Aerospace Information Report (AIR) reviews the precautions that must be taken and the corrections which must be evaluated and applied if the experimental error in measuring the temperature of a hot gas stream with a thermocouple is to be kept to a practicable minimum. Discussions will focus on Type K thermocouples. These are defined in NBS Monograph 125 as nickel-chromium alloy versus nickel-aluminum alloy thermocouples.
This SAE Aerospace Recommended Practice (ARP) defines the nomenclature of temperature measuring devices. General temperature measurement related terms are defined first, followed by nomenclature specific to temperature measuring devices, particularly thermocouples.
SAE Aerospace Information Report AIR1871 provides valuable insight into lessons learned in the development, implementation, and operation of various health monitoring systems for propulsion engines and drive train systems. This document provides an overview of the lessons learned for ground-based systems, oil debris monitoring systems, lubrication systems, and Health and Usage Monitoring Systems (HUMS) for military and commercial programs. For each case study, this document presents a brief technical description, the design requirements, accomplishments, lessons learned, and future recommendations. The lessons learned presented in this document represent a fragment of the knowledge gained through experience when developing and implementing a propulsion health management system. Previous versions of this document contain additional lessons learned during the 1980’s and 1990’s that may be of additional value to the reader.
The effectiveness of Engine Life Usage Monitoring and Parts Management systems is largely determined by the aircraft-specific requirements. This document addresses the following areas: safety, life-limiting criteria, life usage algorithm development, data acquisition and management, parts life tracking, design feedback, and cost effectiveness. It primarily examines the requirements and techniques currently in use, and considers the potential impact of new technolog to the following areas: parts classification and control requirements, failure causes of life-limited parts, engine life prediction and usage measurement techniques, method validation, parts life usage data management, lessons learned, and life usage tracking benefits. SAE ARP1587 provides general guidance on the design consideration and objectives of monitoring systems for aircraft gas turbine engines.
This SAE Aerospace Recommended Practice (ARP) provides guidance for the design of flanges on temperature sensors intended for use in gas turbine engines. Three figures detail the configuration of standard size flange mounts with bolt holes, slotted flanges, and miniaturized flanges for small probes.
ARP5120 provides recommended best practices, procedures, and technology to guide the physical and functional design, development, integration, verification, and validation of highly reliable Engine Health Management (EHM) systems for aircraft engines and Auxiliary Power Units (APUs). This SAE Aerospace Recommended Practice (ARP) also serves as a concise reference of considerations, approaches, activities, and requirements for producing the end-to-end engine health management system comprised of both on and off-board subsystems for the sensing, acquisition, analysis, detection, and data handling functions for EHM. These functions may also be used to effect continued operation or return to service decisions when demonstrated as compliant with the applicable airworthiness requirements defined by the responsible Aviation Authority. Where practical, this document delineates between military and commercial practices.
The purpose of this SAE Aerospace Information Report (AIR) is to present a quantitative approach for evaluating the performance and capabilities of an Engine Monitoring System (EMS). The value of such a methodology is in providing a systematic means to accomplish the following: 1 Determine the impact of an EMS on key engine supportability indices such as Fault Detection Rate, Fault Isolation Rate, Mean Time to Diagnose, In-flight Shutdowns (IFSD), Mission Aborts, and Unscheduled Engine Removals (UERs). 2 Facilitate trade studies during the design process in order to compare performance versus cost for various EMS design strategies, and 3 Define a “common language” for specifying EMS requirements and the design features of an EMS in order to reduce ambiguity and, therefore, enhance consistency between specification and implementation.