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2015-09-15
Technical Paper
2015-01-2592
Joao Pedro Malere, Wlamir Olivares Loesch Vianna
Abstract This paper presents a method to determine the root cause of an aircraft component failure by means of the aircraft fault messages history. The k-Nearest Neighbors (k-NN) and the Tree-Augmented naive Bayes (TAN) methods were used in order to classify the failure causes as a function of the fault messages (predictors). The contribution of this work is to show how well the fault messages of aircraft systems can classify specific components failure modes. The training set contained the messages history from a fleet and the root causes of a butterfly valve reported by the maintenance stations. A cross-validation was performed in order to check the loss function value and to compare both methods performance. It is possible to see that the use of just fault messages for the valve failure classification provides results that close to 2/3 and could be used for faster troubleshooting procedures.
2015-09-15
Technical Paper
2015-01-2590
Yufei Lin, Zakwan Skaf, Ian Jennions
Abstract In the past few decades the number of airplanes has increased dramatically and aircraft systems have become increasingly more complex. Under these conditions, the next generation of airplanes will undergo substantial changes and will make significant technical progress to improve operational safety. This vision is entirely consistent with the adoption of Integrated Vehicle Health Management (IVHM) technology which uses merging of interdisciplinary trends to carry out safe and effective vehicle operation. Hitherto, IVHM has made much progress in the realm of maintenance and operation, but little on safety assessment. This paper discusses the issues around how IVHM could be used to aid the operational safety assessment in the aviation industry. Special attention is paid to existing safety assessment methods, and some challenges and promising research directions are highlighted.
2015-09-15
Technical Paper
2015-01-2619
Karl-Otto Strömberg, Stefan Borgenvall, Mohamed Loukil, Bertrand Noharet, Carola Sterner, Magnus Lindblom, Orjan Festin
Abstract Lightweight Production Technology (LWPT) is today a well-established technology in the automotive industry. By introducing light weight fixtures manufactured from Carbon Fiber Reinforced Plastics (CFRP) in aeronautical applications, new challenges as well as possibilities of in-situ health monitoring emerges. The present paper present results from experimental investigations using optical fibers with multiplex Bragg gratings (FBG) as strain gauges in an industrial CFRP fixture. Fixtures were manufactured of laminates made from CFRP. Measurements have been performed on a single CFRP beam with dimensions (8000 × 500 × 500 mm), used as a structural part in a larger assembly (9000 × 4000mm). The optical fibers were placed in between two laminates on two sides of the beam. The measurement data from the FBGs were compared and correlated to the measured displacements of the beam and the applied loads.
2015-09-15
Technical Paper
2015-01-2555
Ephraim Suhir, Alain Bensoussan, Johann Nicolics
There is a concern that the continuing trend on miniaturization (Moore's law) in IC design and fabrication might have a negative impact on the device reliability. To understand and to possibly quantify the physics underlying this concern and phenomenon, it is natural to proceed from the experimental bathtub curve (BTC) - reliability “passport” of the device. This curve reflects the combined effect of two major irreversible governing processes: statistics-related mass-production process that results in a decreasing failure rate with time, and reliability-physics-related degradation (aging) process that leads to an increasing failure rate. It is the latter process that is of major concern of a device designer and manufacturer. The statistical process can be evaluated theoretically, using a rather simple predictive model.
2015-09-15
Technical Paper
2015-01-2587
Matthew Smith, Peter F. Sulcs, Rhonda Walthall, Mark Mosher, Gregory Kacprzynski
Abstract The Aircraft System Health Management (ASHM) tool is a UTC developed web application that provides access to Aircraft Condition Monitoring Function (ACMF) reports and Flight Deck Effects (FDE) records for Boeing 787®, A320®, and A380® aircraft. The tool was built with a flexible architecture to field a range of off-board diagnostics and prognostics modules designed to transform an abundance of data into actionable and timely knowledge about fleet health. This paper describes the system architecture and implementation with a focus on “lessons learned” in applying diagnostic and prognostics algorithms to available fleet data. Key topics include ensuring analytic robustness, design for cross-enterprise collaboration and defining a workable approach to testing, validating and deploying prognostics and diagnostics models with various degrees of complexity. A case study is provided related to fluid leak detection within an environmental control subsystem.
2015-09-15
Technical Paper
2015-01-2593
Jonathan L. Geisheimer, Michael Wabs, Carlos Carvalho
Abstract Time Domain Reflectometery (TDR) is a Radio Frequency (RF) technology that has been used for many years to find cable breaks and measure fluid levels in industrial processes. The technology uses picosecond length pulses and the associated reflections off the fluid surface in a time of flight measurement to determine fluid height. TDR signals have additional information that can be processed and utilized for Integrated Vehicle Health Management (IVHM) applications. For example, when water collects in the fuel tank, TDR is capable of identifying and measuring the amount of water. This can allow the water sumps to be drained on condition instead of on a schedule. In addition, electromagnetic properties of the fluid can be determined, such as the dielectric constant, which can be used to identify mis-fueling situations, contaminants in the fluid, and potentially other fluid health properties.
2015-09-15
Journal Article
2015-01-2397
Angelo C. Conner, Luis Rabelo
Abstract In planning, simulation models create microcosms, small universes that operate based on assumed principles. While this can be powerful, the information it can provide is limited by the assumptions made and the designed operation of the model. When performing schedule planning and analysis, modelers are often provided with timelines representing project tasks, their relationships, and estimates related to durations, resource requirements, etc. These timelines can be created with programs such as Microsoft Excel or Microsoft Project. There are several important attributes these timelines have; they represent a nominal flow (meaning they do not represent stochastic processes), and they are not necessarily governed by dates or subjected to a calendar. Attributes such as these become important in project planning since timelines often serve as the basis for creating schedules.
2015-09-15
Journal Article
2015-01-2440
Robert Moehle, Jason Clauss
Abstract Labor costs rank second only to fuel in expenses for commercial air transports. Labor issues are a growing concern in the airline industry, with an impending worldwide pilot shortage. One solution proposed and requested by some of the industry leaders is to allow a single flight crew member to operate the aircraft. Safety concerns represent the dominant barrier to single-pilot Part 121 operations. The FAA and Congress consistently demonstrate a bias toward conservatism in their regulation of airlines and commercial aircraft. Bureaucrats and the general public fall prey to isolated news stories that highlight pilot error and anchor their viewpoint on further regulating a two-person crew. Yet, in an alarming spate of recent airline accidents, the presence of multiple crewmembers did nothing to prevent, and actually may have contributed to, the crash. Technology is not the problem.
2015-09-15
Journal Article
2015-01-2545
Reza Ahmadi, Oliver Marquardt, Marc Riedlinger, Reinhard Reichel
Abstract Aircraft cabin systems, especially cabin management systems (CMS) have to cope with frequent cabin changes during their lifecycle. This includes not only layout rearrangements and technological upgrades during the service, but also extensive CMS customizations and product variations before aircraft delivery. Therefore it is inevitable for the CMS to be highly changeable and offer an easy and agile change process. Today's CMS solutions face this challenge with configurable system architectures. Although such architectures offer a vast change domain, they usually come with time consuming and error prone change processes. This paper introduces an adaptive avionics software architecture that enables the CMS to cope with cabin changes highly automatically and with minimal human interactions. The adaptation is performed during an on ground organization phase, in which system changes are detected and evaluated by the CMS itself.
2015-09-10
Book
Tim King
A keen focus on operations, cost management, leadership, and customer service is presented in this book for fleets to thrive in today’s competitive business environment. Basic concepts and customer service fundamentals, along with integrated best practices, and business tools are fully described. This model can be applied by service groups of any size to achieve quality performance benefits for both the customer and the fleet-provider. Fleet Services: Redefining Success presents: • A back-to-basics approach that begins by redefining a fleet's customers to fully identify and provide customer-driven services. • A hierarchy for success that includes development of management goals and strategies to exceed customer expectations. • Best practices and associated business tool requirements that assure exceptional service and win-win results. • An innovative business model that maximizes opportunities and positive outcomes for fleet service providers.
2015-09-07
Standard
ARP4990B
This SAE Aerospace Recommended Practice (ARP) provides to the aerospace industry a procedure for the consistent and accurate calculation of fuel flow using turbine flowmeters during development, production, and post overhaul/repair gas turbine engine testing.
2015-09-07
Standard
ARP5533A
This SAE Aerospace Recommended Practice (ARP) covers the requirements for a Stationary Runway Weather Information System (referred to as the system) to monitor the surface conditions of airfield operational areas to ensure safer ground operations of aircraft. The system provides (1) temperature and condition information of runway, taxiway, and ramp pavements and (2) atmospheric weather conditions that assist airport personnel to maintain safer and more efficient airport operations. The system can be either a wired system or a wireless system.
2015-09-06
Technical Paper
2015-24-2530
Mohamed El Morsy, Gabriela Achtenova
Abstract A vehicle gearbox serves for torque and speed conversion with help of rotating elements. Therefore the gearbox experiences periodic excitation forces with a fundamental frequency following the rotation frequency. These excitation forces give rise to corresponding periodic response signals, i.e. signals having content at the fundamental (rotational) frequency and its harmonics. Order analysis is an analysis technique which is used to extract these harmonic orders from the response signals. This article intends to use the order tracking analysis for gearbox fault diagnosis under variable speed conditions to compare between healthy and faulty cases by using order extraction. Finally, determine maximum Root Mean Square (RMS) as severity index.
2015-09-06
Journal Article
2015-24-2465
George Bergeles, Jason Li, Lifeng Wang, Foivos Koukouvinis, Manolis Gavaises
Abstract Despite numerous research efforts, there is no reliable and widely accepted tool for the prediction of erosion prone material surfaces due to collapse of cavitation bubbles. In the present paper an Erosion Aggressiveness Index (EAI) is proposed, based on the pressure loads which develop on the material surface and the material yield stress. EAI depends on parameters of the liquid quality and includes the fourth power of the maximum bubble radius and the bubble size number density distribution. Both the newly proposed EAI and the Cavitation Aggressiveness Index (CAI), which has been previously proposed by the authors based on the total derivative of pressure at locations of bubble collapse (DP/Dt>0, Dα/Dt<0), are computed for a cavitating flow orifice, for which experimental and numerical results on material erosion have been published. The predicted surface area prone to cavitation damage, as shown by the CAI and EAI indexes, is correlated with the experiments.
2015-09-03
Book
Samir Khan, Ian K. Jennions, Paul Phillips, Chris Hockley
Today, we are all strongly dependent on the correct functioning of technical systems. They fail, and we become vulnerable. Disruptions due to degradation or anomalous behavior can negatively impact safety, operations, and brand name, reducing the profitability of all elements of the value chain. This can be tolerated if the link between cause and effect is understood and remedied. Anomalous behavior, which indicates systems or subsystems not acting in accordance with design intent, is a much more serious problem. It includes unwanted system responses and faults whose root cause can’t be properly diagnosed, leading to costly, and sometimes unnecessary, component replacements. The title No Fault Found: The Search for the Root Cause was developed to propose solutions to this technical and business challenge, which has become less and less acceptable to the commercial aviation industry globally.
2015-09-01
Journal Article
2015-01-9001
Tarapong Sreenuch, Ian Jennions
For Integrated Vehicle Health Management (IVHM) technology to fully achieve its promise, there is a need for integration architecture to support interoperability between multiple vendors' IVHM components and insertion of new IVHM capabilities. To date there have been very limited studies on different approaches in integrating IVHM components. This paper presents design candidates for plug-and-play (PnP) IVHM architecture. The open standard based designs are derived from desired IVHM data flow characteristics and system configuration requirements. The designs and enabling middleware technologies are qualitatively and empirically evaluated for their adequacy and effectiveness. The qualitative assessment focuses on the implementation and system configuration based on different test scenarios. The empirical performance is measured in terms of latency (in both normal and intermittent network connections) and throughput.
2015-08-28
Standard
J1939/73_201508
SAE J1939-73 Diagnostics Application Layer defines the SAE J1939 messages to accomplish diagnostic services and identifies the diagnostic connector to be used for the vehicle service tool interface. Diagnostic messages (DMs) provide the utility needed when the vehicle is being repaired. Diagnostic messages are also used during vehicle operation by the networked electronic control modules to allow them to report diagnostic information and self-compensate as appropriate, based on information received. Diagnostic messages include services such as periodically broadcasting active diagnostic trouble codes, identifying operator diagnostic lamp status, reading or clearing diagnostic trouble codes, reading or writing control module memory, providing a security function, stopping/starting message broadcasts, reporting diagnostic readiness, monitoring engine parametric data, etc.
2015-08-28
Standard
J2064_201508
The Scope of SAE J2064 covers coupled hose assemblies intended for containing and circulating lubricant, liquid and gaseous R134a and/or R-1234yf refrigerant in automotive air-conditioning systems. Historically, requirements for the hose used in coupled automotive refrigerant air conditioning assemblies was included in SAE J2064. SAE J2064 has been changed to establish the requirements for factory and field coupled hose assemblies. SAE J3062 has been issued to define requirements for the hose used in these assemblies into its own standard. SAE J2064 also provides the necessary values used in SAE J2727 Mobile Air Conditioning System Refrigerant Emission charts for R-134a and R-1234yf. The certified coupling of MAC hose assemblies is required in meeting certain regulatory requirements. A hose which has met the requirements of SAE J3062 and certified in J2911 must be used as part of the coupled assembly.
2015-08-25
Standard
AIR6326
The objective of this document is to define basic terms and definitions and to provide general guidance for M&S of aircraft EPS.
2015-08-24
Standard
ARP6028A
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.
2015-08-24
Standard
AMS1424L
This specification covers a deicing/anti-icing material in the form of a fluid.
2015-08-21
WIP Standard
ARP6344
This Aerospace Recommended Practice (ARP) establishes a test procedure and recommended surge pressure limit value for the evaluation of fixed aircraft pressure fuel dispensing systems. Note: This ARP is not applicable to aerial refueling systems or mobile aircraft refueling systems (trucks, hydrant servicing vehicles, etc.). Testing of aerial refueling systems is addressed in ARSAG documents. Testing of mobile refueling systems is addressed in ARP 5918. Note: This ARP does not address requirements that may be specific to the testing of shipboard aircraft refueling systems.
2015-08-13
Standard
ARP5818A
This document is a guideline for the design and operation of Aviation Aircraft Refueling Vehicles and for the materials, components, and systems used thereon. The criteria set forth herein are the minimum recommendations for all types of aircraft refueling vehicles, including tanker vehicles, hydrant service vehicles, towable hydrant carts, fixed refueling cabinets, and any other type of aircraft refueling vehicles used at airports for aircraft refueling operations with nominal operating fuel pressures and flow rates as specified within this document.
2015-08-10
Standard
AS5282A
This SAE Aerospace Standard (AS) establishes requirements for the manufacture and certification of tool steel rings for magnetic particle inspection.
2015-08-07
Standard
AS5562
This SAE Aerospace Standard (AS) establishes minimum ice and rain performance criteria for electrically-heated pitot and pitot-static probes intended for use on the following classes of fixed-wing aircraft and rotorcraft. The classes of fixed-wing aircraft are defined by aircraft flight envelopes and are shown in Figure 1. The flight envelopes generally fall into the classes as shown below: Class 1: Cruise altitude ≤ 23 000 feet Class 2: Cruise altitude ≤ 31 000 feet Class 3: Cruise altitude ≤ 42 000 feet Class 4: Cruise altitude > 42 000 feet Class R: Rotorcraft The user of this standard must evaluate the aircraft level installation requirements for the probe against the class definition criteria to ensure adequate coverage for the application. It may be necessary to step up in class or modify the test conditions in order to meet the applicable installation requirements. NOTE: Class 2 is divided into two subgroups identified as either Class 2a or Class 2b.
2015-08-05
WIP Standard
AS4786B
This SAE Aerospace Standard (AS) covers variable speed, reversible battery powered drills with removable, rechargeable battery pack and either 3/8 inch or ½ inch chuck used for general maintenance and construction where a battery powered tool is required. This document also satisfies EMI requirements for driver drills, where EMI suppression is required by the purchaser. This document may involve hazardous materials, operations, or equipment and does not purport to address all of the safety considerations associated. It is the responsibility of the user of a piece of equipment to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to its use. Users are cautioned to read all manufacturer’s instructions prior to use.
2015-08-05
WIP Standard
AS28431B
This SAE International Aerospace Standard covers requirements for micrometer adjustable, feel impulse, torque wrenches. The torque wrench is used to apply a pre-set torque to threaded fasteners and other torque requirements.
2015-08-05
WIP Standard
AS4984B
This SAE Aerospace Standard (AS) covers requirements for nickel-chromium coatings, black oxide or black phosphate coatings, and alternate coatings for aerospace hand tools.
2015-08-05
WIP Standard
AS954H
This SAE Aerospace Standard (AS) covers high strength thin wall (commercial) sockets, universal sockets, box wrenches and torque adaptors which possess the strength, clearances, and internal wrenching design so configured that, when mated with 12-point fasteners conforming to the requirement of AS870, they shall transmit torque to the fastener without bearing on the outer 5% of the fastener's wrenching points. Inclusion of dimensional data in this document is not intended to imply that all of the products described herein are stock production sizes. Consumers are requested to consult with manufacturers concerning lists of stock production sizes. The dimensional limits of box and combination wrench lengths have been established to provide configuration control for tool storage applications.
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