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Through the use of an “Integrated Product Team” approach and new inspection techniques incorporating the latest in imaging capabilities and automation, the costs of some man-power intensive tasks can now be drastically reduced. Also, through the use of advanced eddy current techniques, the detectable size of cracks under flush-head fasteners can be reduced while maintaining reliable inspection. This article describes the evaluation and results obtained using eddy current technology to determine the minimum fasteners, Secondly, it describes the integrated efforts of engineers at Boeing DPD and Northwest Airlines in the successful application of MAUS eddy current scanning of the DC-10 circumferential and axial crow splices. The eddy current scanning greatly reduced the man-hour effort required for the existing radiographic inspection

The aircraft polar must be determined with high degree of accuracy in order to derive the data related to the aircraft performance. At level and constant speed flight, thrust equals drag. Methods for calculating thrust, and therefore drag, are discussed. This work describes the application of two methods for the calculation of in-flight thrust determination and contains a description of the relevant methods and their implementation in a user friendly computer program, together with actual flight data. Inflight thrust calculations for several flight conditions are performed and the results compared.

In this work, the need of the CAD systems of making available to the user means of manipulating the created solid models in a more flexible way is emphasized. It will be showed the historical evolution of these systems and the growing need of models capable to represent a larger volume of information and manipulate them consistently. The parametric and variational methodologies come as a good option for the consistent and automatic manipulation of changes imposed by the designer, supporting the interactive nature of a product development process. The importance of the sequence of operations adopted by the designer when defining the computational model is verified and two functions, UNDO and REDO, were identified as necessary for a satisfactory manipulation of solid models in CAD systems based on the history of operations execution. For a consistent support to these functions, it is necessary the maintenance of dependency information among the executed operations.

It is an unpublished project that comes to show the methodology and the development which was used for the construction of an orientation guide for the development of the eye type fixations. After studies and surveys it was possible to deparate this fixation type in groups of similar products. Through sampling studies, accomplished tests and statical studies, the methodology presented here could be consecrated with success, allowing be used in other types of fixations. Here it will be seen the traveled paths and the form it was developed. It is not objective of this work to present the built guide for the engineering of the company products.

This paper reports the results of a comprehensive project investigating the performance of a Ricardo Hydra direct injection diesel engine and concentrates on the application of the two-colour technique for obtaining quantitative data from the photographs of the combustion process. Tests have been performed on the engine over a wide range of operating conditions, but this paper focus on the effects of injection timing on diesel combustion. The results gave information on the distribution of temperature and soot in the combustion chamber during the burning process, and this information correlated well with gross emission measurements of smoke and oxides of nitrogen carried out on the standard version of the engine.

This paper will show the complexity of International Product Management inside huge companies. The following presentation will show practical solutions to sort some problems out as well as the supplier selection process. Then we will present how optimize different processes, activities and departments using EDM as an integration platform.

This work presents an evaluation of one liter capacity, 4 cylinder engine operating with ‘Exhaust Gas Recirculation’ (EGR) at two compression ratios, 8.9:1 and 9.6:1. The compression ratio is increased, geometrically, within tolerable limits. This is achieved by a reduction in volume of the combustion chamber in order to bring the overall performance of the engine up to the results achieved before the engine was using EGR. The results indicate that the gain in efficiency obtained through increased compression ratios is maintained even with EGR. Moreover, after a certain percentage of the recirculation, the nitrogen oxide (NOX) and carbon monoxide (CO2) emissions are lower than the original engine. Depending on the engine speed, however, the emission of unburned hydrocarbons (HC) are higher than the original engine, and depending on the percentage of EGR, there is a slight loss of torque and power compared to the original.

Due to the more stringent emissions regulations the catalytic converter has to move closer to the engine. In this hostile environment it is important to have a mechanically durable system, which survives under these severe conditions. This paper shows the evaluation and system design for a close coupled converter. The mechanical durability of this system was proven during an on-road-durability test. During the entire test temperatures were measured inside the converter, at the shell and in the engine compartment to show the thermal management of this system.

Naval Aviation has expanded its efforts to eliminate mishaps; especially those linked to human error. This focus was expanded to cover not only aircrew error, but maintainer error as well. To examine maintenance error, the Naval Safety Center's Human Factors Accident Classification System (HFACS) was adapted to analyze eight fiscal years of major maintenance mishaps. The HFACS Maintenance Extension effectively profiled the nature of maintenance errors and depicted the latent supervisory and maintainer conditions that “set the stage” for subsequent unsafe maintainer acts.

This paper focuses on human factors in maintenance documentation that could be the root cause of human errors. To be proactive, maintenance engineers should explore procedures to prevent maintenance errors during the document preparing process. Then maintenance technicians should follow the documents to complete their tasks in order to reduce human errors. The main purpose of this analysis is to eliminate the potential processes that cause human errors. The involved documents are related to the maintenance process, such as work card and PMDB. Based on the most frequent maintenance human errors, we introduce several analysis principles. Some case studies are used to illustrate the analysis processes and principles as well.

The negative consequences of unsafe behaviors on the job heavily contribute to the rising costs of doing business in terms of both organization dollars and diminished human quality of life. Developing a safety culture provides a positive proactive approach toward creating a working environment where safety is a top priority. An integral part of accomplishing this task is directly related to training individuals on how the interactions that occur among organizational members and the messages their behaviors send influence others' behaviors. This can be best addressed through communication skill development initiatives including mutual responsibility, trust, avoiding punitive strategies and facilitating assertiveness.

This paper compares several different test methods used to test maintenance chemicals for potential to induce hydrogen embrittlement in high-strength steel. The program was structured to accomplish three main objectives with regard to hydrogen embrittlement testing: 1) compare various test methods used to qualify maintenance chemicals, 2) compare various coatings used to protect high-strength steel parts such as landing gear, and 3) compare various high-strength steel substrates specified for aircraft landing gear. The coatings selected included electrodeposited cadmium (baseline), ion vapor deposited (IVD) aluminum, SermeTel 984, and Zinc-Nickel plate. Substrates tested included AISI 4340 (260-280 ksi HT), 300M (280-300 ksi HT), and AerMet 100 (minimum 290 ksi HT).

The 1996 Federal Aviation Reauthorization Act created the National Civil Aviation Review Commission. The legislation charges the Commission with considering future Federal Aviation Administration budget needs and appropriate financing mechanisms, as well as suggesting productivity and safety improvements. On December 11, 1997 the commission issued a report titled Avoiding Aviation Gridlock and Reducing the Accident Rate, A Consensus for Change. The following recommendation is included in the executive summary of that report: “Aviation safety programs in industry and government need to be improved by establishing more effective safety risk management programs. This should include self-audit and self-disclosure programs within aviation companies, protecting and sharing safety information in non-punitive ways, and encouraging research to support these activities. Where possible, these programs should include the analysis of real flight and operational data.

This paper presents a model which is representative of the current environment within which most domestic repair stations performing work for air carriers operate. The model illustrates how the successful habits of visionary companies, as documented by Collins and Porras (1997), could be applied to the aviation industry and how Human Factors education could be used to effect a long-term change in the aviation safety culture. A review of the current research on Human Factors in maintenance strongly indicates that the various types of training programs have been effective in raising the awareness of safety issues among the participants, but the applications of those principles to advance safety have been limited by the absence of a systemic management vision. An incremental and radical change in the aviation safety culture could be sought by educating the future workforce in using Human Factors in maintenance and management practices.

The Federal Aviation Administration (FAA) and aircraft manufacturers have adopted industry standards used for training, qualification, and certification of personnel performing nondestructive tests on general aviation aircraft. This can result in higher maintenance costs for the customer, increased aircraft down time, and loss of income for the airframe and powerplant (A&P) technician. In some cases, it is hard to find someone who is technically qualified and competent to do the prescribed inspections. This paper proposes a modification to the current system which would allow A&P technicians to perform necessary nondestructive tests on general aviation aircraft.

The international air transportation industry has slowly evolved towards reaching a seamless global aviation environment. Today's industry requires civil aviation authorities worldwide to perform their oversight functions in a manner involving the understanding of one another's regulatory requirements and ensuring they are met regardless of where the aircraft is operated or what country of registry it flies under. To accomplish this task several aviation assessment programs have emerged all reactions to significant aviation events of the past decade.

There is a growing concern about a forecasted increase in total aircraft accidents due to the expansion of the industry, and the contribution of aircraft maintenance to aviation safety. In that context, this article will examine aircraft maintenance control at the level of the maintenance professionals. Although no clinical testing can verify the attached thesis, this paper initially identifies the need to ensure suitable qualifications of personnel involved in the maintenance and certification of registered aircraft and aeronautical products. It continues by further defining maintenance control by examining current methods and the objectives of licensing. This results in dividing licensing concerns into three fundamental elements; technical or task based competency, regulatory or data control competency, and currency of experience.

Existing bearing technology has not kept up with improved permanent fasteners that are interference fit installed to improve in-service fatigue life. Bearing net-fit service life problems are, elevated temperature and loss of lubrication, causing rolling contact fatigue and RPM noise, bearing migration, high stress amplitude and fretting fatigue lug failure. The high fatigue bearing is manufactured with a predetermined radial looseness of the outer race. This bearing, when installed into existing hole sizes, the press-fit must exceed the elastic range into the compressive plastic zone of the outer race. Only in the compressive plastic zone is the diameter of the outer race stabilized to maintain radial bearing clearances and fabrication tolerances. This bearing concept may be used on ball, roller and spherical bearings and bushings. It is not intended to replace all existing bearings.

The Federal Aviation Administration Airworthiness Assurance Nondestructive Inspection Validation Center (FAA-AANC) is currently conducting a detection reliability study pertaining to the detection of cracks in multi-layered aluminum sheets. This paper describes the design, production and characterization of test specimens that are currently being used to conduct third layer Probability of Detection (PoD) experiments. Pertinent aspects of the lap splice joints for Boeing 737 aircraft, Line Numbers 292 - 2565 are included in the test specimens. A preliminary analysis of the data indicates that for some inspectors, traditional measures of performance - in particular PoD curves based on maximum likelihood fit to two-parameter lognormal curve - may be misleading.

The present work carries out static and kinematical studies of front suspensions of a Brazilian medium sized passenger car. The concept of virtual prototyping with the use of multibody system modelling techniques is employed by ADAMS, a package developed by Mechanical Dynamics Inc.. The concept of virtual prototyping allows vehicle development without the need of physical prototype construction. ADAMS uses the description of the geometric suspension, inertia parameters from its parts and how the parts are connected to generate a full model of the system. The type of analysis which can carry out include vertical and steering behaviour (in the case of a front suspension). These analysis are generated in graphical as well as an animation. The results include among others: toe-in angle, camber and caster angle, ride rate, and so forth. The use of the virtual prototyping concept, has made easier the modelling and analysis of this type of mechanism.