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Thrust measurement systems come in many sizes and shapes, with varying degrees of complexity, accuracy and cost . For the purposes of this information report, the discussions of thrust measurement will be limited to axial thrust in single-axis test systems.

This paper describes a recommended practice and procedure for the correlation of test cells that are used for the performance testing of APU (auxiliary power unit) engines. Test cell correlation is performed to determine the effect of any given test cell enclosure and equipment on the performance of an engine relative to the baseline performance of that engine. The baseline performance is generally determined at the original equipment manufacturer (OEM) designated test facility. Although no original equipment manufacturer (OEM) documents are actually referenced, the experience and knowledge of several OEMs contributed to the development of this document. Each engine Manufacturer has their own practices relating to correlation and they will be used by those OEMs for the purpose of establishing certified test facilities.

This SAE Aerospace Information Report (AIR) provides descriptions of test procedures and established practices for the application, use, and administration of the conduct of icing testing for all types of turbine engines in conventional supercooled liquid (14 CFR Part 25 Appendix C) environmental conditions in ground test facilities (sea-level and altitude) for icing certification purposes.

This paper describes a recommended practice and procedure for the correlation of test cells that are used for the performance testing of turboprop and turboshaft engines. This Aerospace Recommended Practice (ARP) shall apply to both dynamometer and propeller based testing. Test cell correlation is performed to determine the effect of any given test cell enclosure and equipment on the performance of an engine relative to the baseline performance of that engine. Although no original equipment manufacturer (OEM) documents are actually referenced, the experience and knowledge of several OEMs contributed to the development of this document. Each engine manufacturer has their own practices relating to correlation and they will be used by those OEMS for the purpose of establishing certified test facilities.

This document describes a recommended practice and procedure for the trending of parameters to maintain the test cell correlation status. Trending is performed to monitor test cells for changes that can affect engine performance or the data acquired from engine tests.

This SAE Aerospace Recommended Practice (ARP) describes a recommended practice and procedure for the correlation of test cells that are used for the performance testing of turbofan and turbojet engines. Test cell correlation is performed to determine the effect of any given test cell enclosure and equipment on the performance of an engine relative to the baseline performance of that engine. When baseline testing is performed in an indoor test cell, the baseline performance data are adjusted to open air conditions. Although no original equipment manufacturer (OEM) documents are actually referenced, the experience and knowledge of several OEM’s contributed to the development of this document. Each engine Manufacturer has their own practices relating to correlation and they will be used by those OEMs for the purpose of establishing certified test facilities.

The scope of this information report applies to the steady state measurement of direct mass fuel flow in gas turbine engine test cells. A measurement accuracy, and hence uncertainty of between ±0.1 to ±0.2% of value is believed to be achievable for liquid flow applications with some meter models/installations.

Whilst capable of general transient measurement in 50 to 100 Hz region, this type of fuel meter is not capable of rapid transient measurement (in 100 to 250 Hz region). It is also not currently considered suitable for "in flight" fuel flow measurement.

The FAA has issued Advisory Circular, AC43-207, that recommends re-correlation, trending or period checks. The FAA, AC43-207 bases their recommendation on ARP741. This paper describes a recommended practice and procedure for the configuration control requirements to maintain test cell correlation status. This is necessary to maintain performance measurement integrity, particularly when correlation approval is achieved by statistical trending. The configuration of a test facility that exists at the time when a correlation is being carried out should be "base lined" as a condition of correlation approval acceptance, and, be maintained during the time period that the respective correlation approval lasts. This defines test facility configuration control. This is due to the fact that a change in configuration may have the potential to change the established correlation factors and measured engine performance.

This document discusses, in broad general terms, typical present instrumentation practice for post-overhaul gas turbine engine testing. Production engine testing and engine development work are outside the scope of this document as they will typically use many more channels of instrumentation, and in most cases will have requirements for measurements that are never made in post-overhaul testing, such as fan airflow measurements, or strain measurements on compressor blades. The specifications for each parameter to be measured, in terms of measurement range and measurement accuracy, are established by the engine manufacturers. Each test cell instrument system should meet or exceed those requirements. Furthermore, each instrument system should be recalibrated regularly, to ensure that it is still performing correctly.

The FAA has issued Advisory Circular, AC43-207, that recommends re-correlation, trending or period checks. The FAA, AC43-207 bases their recommendation on ARP741. This paper describes a recommended practice and procedure for the configuration control requirements to maintain test cell correlation status. This is necessary to maintain performance measurement integrity, particularly when correlation approval is achieved by statistical trending. The configuration of a test facility that exists at the time when a correlation is being carried out should be "base lined" as a condition of correlation approval acceptance, and, be maintained during the time period that the respective correlation approval lasts. This defines test facility configuration control. This is due to the fact that a change in configuration may have the potential to change the established correlation factors and measured engine performance.

This document describes a method to correct engine thrust, measured in an indoor test cell, for the aerodynamic effects caused by the secondary airflow induced in the test cell by the engine operating in an enclosed environment in close proximity to an exhaust duct. While it is not recommended to be used to replace test cell correlation, it does provide a means to verify an existing thrust correlation factor.

This document is offered to provide state-of-the-art information about design factors that must be considered in the design of new or significantly modified engine test cells used to test propeller equipped turboprop engines in either QEC or bare engine configurations. The report does not address design considerations for test cells designed to test turboprop engines with dynamometer type load absorption devices because they are essentially tested as turboshaft engines. Design considerations for those test cells are presented in AIR4989, Reference 2.1.

This SAE Aerospace Recommended Practice provides recommendations for: the audit process in general; a list of specific areas of attention to be audited; maintaining the test facility in such a manner that it meets audit requirements.

This SAE Aerospace Information Report (AIR) was written because of the growing interest in aircraft installed outdoor engine testing by the Federal Aviation Administration, airlines, charter/commercial operators, cargo carriers, engine manufacturers and overhaul and repair stations. This document was developed by a broad cross section of personnel from the aviation industry and government agencies and includes information obtained from a survey of a variety of operators of fixed and rotary wing aircraft and research of aircraft and engine maintenance manuals.

The paper discusses in general terms the activities required to be undertaken or demonstrated during the establishment of the facility such as: the assessment checks prior to forwarding to the end users site for embodiment into the facility system the establishment of the facility such as trial installations of hardware, functionality checking of lifting transportation and access systems, centerline pull checks, pressure testing of fuel and air start systems, flushing of wet systems and electrical continuity checking. the commissioning of the facility such as instrumentation calibrations, engine starts, engine running, assessment of command and control system, assessment of DAS system, aerodynamic and acoustic surveys. The paper will concentrate on the main engineering engine related aspects of the facility and will not necessarily contain information on the construction validation activities such as HVAC, electrical, facility fire system, waste water etc.

The scope of this information report applies to the steady state measurement of direct mass fuel flow in gas turbine engine test cells. A measurement accuracy, and hence uncertainty of between ±0.1 to ±0.2% of value is believed to be achievable for liquid flow applications with some meter models/installations. Whilst capable of general transient measurement in 50 to 100 Hz region, this type of fuel meter is not capable of rapid transient measurement (in 100 to 250 Hz region). It is also not currently considered suitable for "in flight" fuel flow measurement.

Thrust measurement systems come in many sizes and shapes, with varying degrees of complexity, accuracy and cost . For the purposes of this information report, the discussions of thrust measurement will be limited to axial thrust in single-axis test systems.

This paper describes a recommended practice and procedure for the correlation of test cells that are used for the performance testing of turbofan and turbojet engines. Test cell correlation is performed to determine the effect of any given test cell enclosure and equipment on the performance of an engine relative to the baseline performance of that engine. When baseline testing is performed in an indoor test cell, the baseline performance data are adjusted to open air conditions. Although no original equipment manufacturer (OEM) documents are actually referenced, the experience and knowledge of several OEMs contributed to the development of this document. Each engine Manufacturer has their own practices relating to correlation and they will be used by those OEMS for the purpose of establishing certified test facilities.

This paper describes a recommended practice and procedure for the correlation of test cells that are used for the performance testing of turboprop and turboshaft engines. This Aerospace Recommended Practice (ARP) shall apply to both dynamometer and propeller based testing. Test cell correlation is performed to determine the effect of any given test cell enclosure and equipment on the performance of an engine relative to the baseline performance of that engine.

The intent of this SAE Aerospace Recommended Practice (ARP) is to define and recommend to the Aerospace Industry standardized test procedures for establishing fuel nozzle operating performance including types of tests, controlled and measured parameters, and test configurations.