Compilation of Freezing Brake Experience and Potential Designs and Operating Procedures to Prevent Its Occurrence
This Aerospace Information Report (AIR) describes conditions under which freezing (frozen) brakes can occur and describes operating procedures which have been used to prevent or lessen the severity or probability of brake freezing. This document also identifies design features that some manufacturers implement to minimize the occurrence of freezing brakes. This document is not an Aerospace Recommended Practice (ARP) and therefore does not make recommendations based on a consensus of the industry. However, part of this document’s purpose is to describe the design and operational practices that some are using to minimize the risk of frozen brakes. NOTE: The following information is based upon experience gained across a wide-range of aircraft types and operational profiles, and should NOT take precedence over Aircraft Flight Manual or Flight Operations Procedures.
This document is applicable to military aircraft where stakeholders are seeking guidance on the development and approval of Structural Health Monitoring (SHM) technologies and on the integration of these technologies into encompassing maintenance and operational support systems. The document will refer to those guidelines prepared under SAE ARP6461 that are relevant and applicable to military applications.
This Aerospace Recommended Practice (ARP) was created to help industry deal with existing barriers to the successful implementation of Integrated Vehicle Health Management (IVHM) technology in the aerospace and automotive sectors. That is,given the common barriers that exist, this ARP can be applied not only to aerospace but also to the automotive, commercial and military vehicle sectors. Original Equipment Manufacturers (OEMs) in all of these sectors are heavily dependant upon a large number of component suppliers in order to design and build their products. The advent of IVHM technology has accentuated the need for improved coordination and communication between the OEM and its suppliers –to ensure that suppliers design health ready capabilities into their particular components.
This document has been declared "CANCELLED" by the E32 committee as of April 2016 and has been superseded by ARP5120. By this action, this document will remain listed in the Numerical Section of the Aerospace Standards Index noting that it is superseded by ARP5120. Cancelled specifications are available from SAE.
In order to realize the benefits of Integrated Vehicle Health Management (IVHM) within the aerospace and defense industry there is a need to address five critical elements of data interoperability within and across the aircraft maintenance ecosystem, namely • Approach • Trust • Context • Value • Security In Integrated Vehicle Health Management (IVHM) data interoperability is the ability of different authorized components, systems, IT, software, applications and organizations to securely communicate, exchange data, interpret data, use the information and derive consistent insight from the data that has been exchanged to derive value.
The report shows how the methodology of measurement uncertainty can usefully be applied to test programs in order to optimize resources and save money. In doing so, it stresses the importance of integrating the generation of the Defined Measurement Process into more conventional project management techniques to create a Test Plan that allows accurate estimation of resources and trouble-free execution of the actual test. Finally, the report describes the need for post-test review and the importance of recycling lessons learned for the next project.
Method to Evaluate Aircraft Passenger Seats for the Test Requirements of 14CFR part 25 Appendix F, Parts IV & V
This SAE Aerospace Recommended Practice (ARP) provides an approach for determining which parts on aircraft seats are non-traditional, large, non-metallic panels that need to meet the test requirements of 14CFR Part 25 Appendix F, Parts IV & V.
This report provides data and general analysis methods for calculation of internal and external, pressurized and unpressurized airplane compartment pressures during rapid discharge of cabin pressure. References to the applicable current FAA and EASA rules and advisory material are provided. While rules and interpretations can be expected to evolve, numerous airplanes have been approved under current and past rules that will have a continuing need for analysis of production and field modifications, alterations and repairs. The data and basic principles provided by this report are adaptable to any compartment decompression analysis requirement.
This SAE Aerospace Information Report (AIR) provides a methodology for performing a statistical assessment of gasturbine- engine stability-margin usage. Consideration is given to vehicle usage, fleet size, and environment to provide insight into the probability of encountering an in-service engine stall event. Current industry practices, such as ARP1420, supplemented by AIR1419, and engine thermodynamic models, are used to determine and quantify the contribution of individual stability threats. The statistical technique adopted by the S-16 committee for performing a statistical stability assessment is the Monte Carlo method (see Applicable References 1 and 2). While other techniques may be suitable, their application is beyond the scope of this document. The intent of the document is to present a methodology and process to construct a statistical-stability-assessment model for use on a specific system and its mission or application.
This document provides a review of published methods that have been used to provide estimates of the levels of distortion and/or the concomitant loss of stability pressure ratio that can occur when the recommended full complement of aerodynamic interface plane high-response instrumentation is not used when obtaining inlet data. The methods have been categorized based on the underlying mathematical representation of the aerophysics. Further, the use of maximum value statistics, which has been used to further improve the results where short- duration time records have been employed, is discussed.
This document reviews the state of the art for data scaling issues associated with air induction system development for turbine-engine-powered aircraft. In particular, the document addresses issues with obtaining high quality aerodynamic data when testing inlets. These data are used in performance and inlet-engine compatibility analyses. Examples of such data are: inlet recovery, inlet turbulence, and steady-state and dynamic total-pressure inlet distortion indices. Achieving full-scale inlet/engine compatibility requires a deep understanding of three areas: 1) geometric scaling fidelity (referred to here as just “scaling”), 2) impact of Reynolds number, and 3) ground and flight-test techniques (including relevant environment simulation, data acquisition, and data reduction practices).
This Aerospace Information Report (AIR) is a general overview of typical airborne engine vibration monitoring (EVM) systems applicable to fixed or rotary wing aircraft applications, with an emphasis on system design considerations. It describes EVM systems currently in use and future trends in EVM development. The broader scope of Health and Usage Monitoring Systems, (HUMS ) is covered in SAE documents AS5391, AS5392, AS5393, AS5394, AS5395, AIR4174.
This SAE Aerospace Standard (AS) covers air data computer equipment (hereinafter designated the computer) which when connected to sources of aircraft electrical power, static pressure, total pressure, outside air temperature, and others specified by the manufacturer (singly or in combination) provides some or all of the following computed air data output signals (in analog and/or digital form) which may supply primary flight instruments: pressure altitude; pressure altitude, baro-corrected; vertical speed; calibrated airspeed; mach number; maximum allowable airspeed; overspeed warning; and total air temperature. In addition, the computer may supply one or more of the following signals: pressure altitude, digitized; equivalent airspeed; true airspeed; static air temperature; altitude hold; airspeed hold; mach hold; angle of attack; flight control gain scheduling; and others.
This AIR will address the need for a strategy to achieve aircraft operating certificate holder maintenance efficiencies within the existing regulatory environment as well as the need for regulation, policy, and guidance changes in the long-term to accommodate more complex IVHM solutions. This document will analyse which IVHM solutions can be incorporated within existing maintenance procedures and which also comply with regulations, policy, and guidance. One of the AIR’s objectives is to define best practices for aircraft operating certificate holders to engage with regulators to get approval for simpler IVHM applications leading to maintenance efficiencies. Additionally, this document will analyse the barriers that existing regulations, policy, and guidance present to the implementation of more advanced IVHM solutions. The result is a set of recommendations to certify and implement end-to-end IVHM solutions for the purpose of gaining maintenance efficiencies.
This document is intended for use by designers, reliability engineers, and others associated with the design, production, and support of electronic sub-assemblies, assemblies, and equipment used in ADHP applications to conduct lifetime assessments of microcircuits with the potential for early wearout; and to implement mitigations when required; and by the users of the ADHP equipment to assess those designs and mitigations. This document focuses on the LLM wearout assessment process. It acknowledges that the ADHP system design process also includes related risk mitigation and management; however, this document includes only high-level reference and discussion of those topics, in order to show their relationship to the LLM assessment process.
This SAE Aerospace Recommended Practice (ARP) defines a means of assessing the credibility of computer models of aircraft seating systems used to simulate dynamic impact conditions set forth in Federal Regulations §14 CFR Part 23.562, 25.562, 27.562, and 29.562. The ARP is applicable to lumped mass and detailed finite element seat models. This includes specifications and performance criteria for aviation specific virtual anthropomorphic test devices (v-ATDs). A methodology to evaluate the degree of correlation between a seat model and dynamic impact tests is recommended. This ARP also provides testing and modeling best practices specific to support the implementation of analytical models of aircraft seat systems. Supporting information within this document includes procedures for the quantitative comparison of test and simulation results, as well as test reports for data generated to support the development of v-ATDs and a sample v-ATD calibration report.
This SAE Aerospace Standard (AS) provides a method for gas turbine engine performance computer programs to be written using Fortran COMMON blocks. If a “function-call application program interface” (API) is to be used, then ARP4868 and ARP5571 are recommended as alternatives to that described in this document. When it is agreed between the program user and supplier that a particular program shall be supplied in Fortran, this document shall be used in conjunction with AS681 for steady-state and transient programs. This document also describes how to take advantage of the Fortran CHARACTER storage to extend the information interface between the calling program and the engine subroutine.
This SAE Aerospace Recommended Practice (ARP) document provides recommended practices for the calibration and acceptance of icing wind tunnels to be used in testing of aircraft components and systems and for the development of simulated ice shapes. This document is not applicable to air-breathing propulsion test facilities configured for the purposes of engine icing tests. Use of facilities as part of an aircraft's ice protection Certification Plan should be reviewed and accepted by the applicable regulatory agency prior to testing. Following acceptance of a test plan, data generated in these facilities may be submitted to regulatory agencies for use in the certification of aircraft ice protection systems and components. Certain types of tests may be appropriate in facilities with capabilities that are not as rigorously characterized as by the practices defined herein, and the acceptability of these tests should be coordinated with the applicable regulatory agency.
This document describes a set of standardized reports that can be generated using the logistics product data elements contained in GEIA-STD-0007-B. Each report is defined by selection options, processing, format, report sequence, and data sources. The selection options paragraph identifies recommended mandatory and optional selections that can be made by the user to tailor the report content. The processing paragraph identifies qualifying criteria for report data, report calculations, and specific instructions regarding how the data should be presented on the report. Each report has a sample report showing its format. Report sequences specify the sort criteria for a given report, and each Part/Section within a report. There is an attached listing of data sources for the elements that are on a report. The listing provides the report header for each element; and its GEIA-STD-0007-B data element/attribute along with the appropriate entity.
This handbook is intended to provide additional information on the use and tailoring of the data in GEIA-STD-0007. The standard provides a new approach to Logistics Support Analysis Record (LSAR) (i.e., MIL-STD-1388-2B) data with emphasis on data transfer (e.g., XML Schemas) versus data storage (e.g., relational tables). GEIA-STD-0007 identifies the range of logistics product data that is generated during the development and acquisition of a system or end item. It does not prescribe the supportability analyses required to generate logistics product data. How the data is generated via analysis techniques/tools, how it is stored and processed, and how the data is used to generate specific logistics support products, is left to the performing activity. GEIA-STD-0007 is a data transfer standard implementing the logistics data concepts of GEIA-STD-927, Common Data Schema for Complex Systems.
This standard defines logistics product data generated during the requirements definition and design of an industry or government system, end item or product. It makes use of the Extensible Markup Language (XML) through the use of entities and attributes that comprise logistics product data and their definitions. The standard is designed to provide users with a standard set of data tags for all or portions of logistics product data and customer defined sub-sets of logistics product data. The standard can be applied to any indsutry or government product, system or equipment acquisition program, major modification program, and applicable research and development projects. This standard is for use by both industry and government activities. As used in this standard, the requiring authority is generally the customer and the customer can be a government or industry activity. The performing activity may be either a industry or government activity.
This SAE Aerospace Information Report (AI) provides a review of real-time modeling methodologies for gas turbine engine performance. The application of real-time models and modeling methodologies are discussed. The modeling methodologies addressed in this AIR concentrate on the aerothermal portion of the gas turbine propulsion system. Characteristics of the models, the various algorithms used in them, and system integration issues are also reviewed. In addition, example cases of digital models in source code are provided for several methodologies.
This document defines the process steps involved in collecting and processing engine test data for use in understanding engine behavior. It describes the use of an aero-thermal cycle model for reduction and analysis of those data. The analysis process may include the calculation of modifiers to match the model to measured data, and prediction of engine performance based on that analysis
The guidelines addressed in this Aerospace Information Report (AIR) applies only to the simulation and subsequent data-reduction of inlet total-pressure distortion data from Computational Fluid Dynamic (CFD). The guidelines can be used as part of a turbine-engine inlet-flow-distortion methodology.
Aircraft Turbine Engine Fuel System Component Endurance Test Procedure (Room Temperature Contaminated Fuel)
This SAE Aerospace Recommended Practice describes a method for conducting room temperature, contaminated fuel, endurance testing when the applicable specification requires nonrecirculation of the contaminants. The objective of the test is to determine the resistance of engine fuel system components to wear or damage caused by contaminated fuel operation. It is not intended as a test for verification of the component's filter performance and service life. ARP1827 is recommended for filter performance evaluation. The method described herein calls for nonrecirculation of the contaminants and is intended to provide a uniform distribution of the contaminant at the fuel system inlet. Two systems for contamination addition are included, the conveyer and the slurry injection system.
The test procedure included in this document are used to determine a benchmark SgRP for Class A vehicles where design intent information is unknown.
Presents the seating accommodation model used to determine seat track length for accommodation in design.
This SAE Aerospace Information Report (AIR) is applicable to rotorcraft structural health monitoring (SHM) applications, both commercial and military, where end users are seeking guidance on the definition, development, integration, qualification, and certification of SHM technologies to achieve enhanced safety and reduced maintenance burden based on the lessons learned from existing Health and Usage Monitoring Systems (HUMS). While guidance on SHM business case analysis would be useful to the community, such guidance is beyond the scope of this AIR. For the purpose of this document, SHM is defined as “the process of acquiring and analyzing data from on-board sensors to evaluate the health of a structure.” The suite of on-board sensors could include any presently installed aircraft sensors as well as new sensors to be defined in the future. Interrogation of the sensors could be done onboard during flight or using ground support equipment.
This document describes requirements for standardized processes (and associated technologies) that ensure type design data are retrievable and usable for the life of a type certificate (50+ years). These processes are primarily concerned with, but not limited to, digital type design data retained in threedimensional representations and associated data that is required for complete product definition, such as tolerances, specification call-outs, product structure and configuration control data, etc. This process standard includes process requirements for managing the evolution of technologies required to ensure the availability of the data for the life of the product. This data must be available to meet regulatory, legal, contractual and business requirements. This process standard is not intended to incorporate every company specific requirement and does not dictate specific organizational structures within a company.
This SAE Aerospace Recommended Practice (ARP) provides guidance for the presentation of gas turbine engine transient performance models with the capacity to be implemented as computer programs operating in real time and is intended to complement AS681. Such models will be used in those applications where a transient program must interface with physical systems. These applications are characterized by the requirement for real time transient response. These models require attention to unique characteristics that are beyond the scope of AS681. This document is intended to facilitate the development of mathematical models and the coordination of their requirements with the user. It will not unduly restrict the modeling methodology used by the supplier. The objective of this document is to define a recommended practice for the delivery of mathematical models intended for real time use. Models used in this application may also be contained in deliverable computer programs covered by AS681.