Bombardier Aerospace Research Articles

Bombardier Aftermarket Demand Forecast with Machine Learning

Intermittent demand patterns are commonly present in business aircraft spare parts supply chains. Because of the infrequent arrivals and large variations in demand, aircraft aftermarket demand is difficult to forecast, which often leads to shortages or overstocking of spare parts. In this paper, we present the development and implementation of an advanced analytics framework at Bombardier Aerospace, which is carried out by the Bombardier inventory planning team and IVADO Labs to improve the aftermarket demand forecasting process. This integrated predictive analytics pipeline leverages machine-learning (ML) models and traditional time series models in a single framework in a systematic fashion. We also make use of a tree-based machine-learning method with a large set of input features to estimate two components of intermittent demand, namely demand sizes and interdemand intervals. Through the ML models, we incorporate different features, including those derived from flight data. Outputs of different forecasting models are combined using an ensemble technique that enhances the robustness and accuracy of the forecasts for different groups of aftermarket spare parts categorized by demand patterns. The validation results show an improvement in forecast accuracy of approximately 7% and in unbiased forecast of 5%. The ML-based Bombardier Aftermarket forecasting system has been successfully deployed and used to forecast the aftermarket demand at Bombardier of more than 1 billion Canadian dollars on a regular basis. History: This paper was refereed.

Framework of Multiblock Structured Grid Smoothing Algorithms for Aircraft Configurations

This paper presents the development of a new framework of multiblock structured elliptic grid smoothing for full-aircraft configurations. The framework is fully automated and applies different solvers on blocks based on their properties. Blocks with a solid wall are initialized by algebraic orthogonal grids and solved with a line SOR implicit elliptic solver. The remaining blocks are initialized by transfinite interpolation grids and solved with an SOR explicit elliptic solver. Both solvers apply spacing and curvature source terms. This combination results in orthogonal grids close to walls while imposing elliptic spacing and curvature control using variable relaxation factors in the field, including across the block boundaries. The orthogonality close to the solid walls is improved by using the properties of the initial algebraic orthogonal grids. The code is parallelized using Message Passing Interface for acceleration. The performance of the framework is demonstrated in a first step on 2D problems: a canonical test case and a multi-element high-lift airfoil. In a second step, the performance is analyzed on a full three-dimensional aircraft configurations (wing/body/engine) case at Bombardier Aerospace. The paper examines the effect of the proposed approach through various assessments of grid metrics and flow solver behaviors. In particular, the study highlights the improvements in reducing spurious drag through a far-field drag analysis.

Narrating Dignity: Racial Profiling, National Security and a Muslim Pilot Before The Supreme Court of Canada

This paper analyzes the Supreme Court of Canada’s decision in Quebec (Commission des droits de la personne et des droits de la jeunesse) v. Bombardier Inc. (Bombardier Aerospace Training Center). Almost 12 years after Captain Javed Latif’s ordeal began, the Supreme Court of Canada affirmed a decision by the Quebec Court of Appeal overturning a finding by a Quebec Human Rights Tribunal that Bombardier had discriminated against him. While there is much to celebrate in the Court’s reasons, the decision ultimately exposes and perpetuates a deep unwillingness to challenge the stereotyping of Muslims as terrorists in Canada. In response, this paper seeks to excavate Latif’s fuller story largely through a reading of silences. The Tribunal advanced two discrete but intersecting theories in its finding of discrimination. The Court focused, artificially, on one and found “no evidence” of discrimination. The Supreme Court not only ended Captain Latif’s quest for a remedy, it re-wrote his narrative by moving attention away from key facts involving his interactions with Bombardier. The Court’s chosen narrative also regulated the collective fears and aspirations of Muslim communities in Canada to the realm of the unsaid. At a time when Muslims are struggling to counter popular and official stereotypes that construct them as incorrigible barbarians and outsiders who are prone to terrorism and violence, it is important to create spaces for counter-narratives to be heard and lived experiences to be validated. Moreover, litigants who dedicate years of their lives to advancing social justice causes deserve the dignity of recognizing their own stories when relayed back to them by the legal process. The comparison of the Court’s reasons with that of the Tribunal thus represents a political act of hearing counter-narratives while also critically analyzing the Supreme Court’s claim that the Tribunal had little or no evidence before it to ground its finding of discrimination.

You can't judge a book by its cover: evolving professional responsibilities, liabilities and 'judgecraft' when a party has Asperger's Syndrome

In the context of increasing legal emphasis on fairness for people with disability, this article analyses the responsibilities and liabilities of lawyers in relation to the recognition and identification of client disability, and specifically Asperger's Syndrome, prior to a hearing. This article also analyses the judge's responsibilities when a party has Asperger's Syndrome. Lord Justice Gillen's seven points of principle and practical guidance for fair hearings when a party has a disability (Galo v Bombardier Aerospace UK) are used as a framework to explore the art of judging, or 'judgecraft'.

NSU3D Results for the Second AIAA High-Lift Prediction Workshop

Simulation results for the second AIAA CFD High-Lift Prediction Workshop using the unstructured computational fluid dynamics code NSU3D are presented. The solution algorithms employed in NSU3D for this study are described along with examples of convergence history and computational cost. The geometry used for the simulation consists of the DLR-F11 wing–body with high-lift system deployed in a landing configuration. This geometry is representative of a modern transport aircraft high-lift system that has been tested experimentally over a suitable Reynolds number range. Results are presented from two sets of computational studies, the first performed at the University of Wyoming using standard workshop unstructured meshes, and the second performed at Bombardier Aerospace using in-house-generated meshes. In both cases, results are presented for two different turbulence models, allowing an assessment of the sensitivity of the results to grid densities, grid types, and turbulence models. Results consist of computed force and moment coefficients across a range of angles of attack and for two different Reynolds numbers, as well as surface pressure profiles and off-body velocity profiles, all of which are compared with experimental data. The results compare favorably with experimental data and generally fall within the standard deviation of the workshop collective results. Computations using the Spalart–Allmaras turbulence model tend to overpredict the maximum lift value and incidence, while results using the model tend to underpredict the maximum lift value. The best agreement in terms of force coefficients is observed with the turbulence model using the Bombardier internally generated meshes.

Taking Ideas from Paper to Practice: A Case Study of Improving Design Processes through Detailed Modeling and Systematic Analysis

This paper presents a project conducted at Bombardier Aerospace aimed at shortening span time and reducing duplicated effort during design. The current design processes were modeled at a high level of detail and analyzed for opportunities for improvement. After investigation of the critical paths and duplicated tasks, suggestions were proposed to add resources to critical tasks and to eliminate duplicated tasks by having only one department do them for all departments. Simulation of the suggested scenarios showed that span time could be reduced by more than 20% with almost no change in effort.

Fly-over aircraft noise measurement campaign at Montreal-Trudeau airport using a microphone array

Engines being quieter due to high by-pass ratios, the airframe noise, produced for instance by landing gears or high-lift devices, has become a significant contributor to the total noise radiated by aircraft during approach and landing. As part of the investigations carried out to understand noise generation mechanisms, the beamforming techniques developed over the last decade and applied to microphone array measurements have shown to be effective tools for localization and quantification of these aerodynamic noise sources. In order to validate their in-house beamforming softwares, Bombardier Aerospace and the Groupe d’Acoustique de l’Université de Sherbrooke have conducted a 5-day measurement campaign in June 2012. The 95-microphone array was located on the roof of a building next to the Montreal-Trudeau airport. Aircraft position was determined by two high-definition cameras, both synchronized with the microphone array by inter-range instrumentation group time codes generators. This paper summarizes the measurement campaign. The aircraft tracking tool and the beamforming algorithms used to characterize the noise sources are presented. Several Bombardier CRJ fly-overs were recorded during this test. Beamforming results obtained for different airlines are compared in order to evaluate the repeatability of the method.

A case study to estimate costs using Neural Networks and regression based models

Article history: Received September 9, 2010 Received in revised format June 5, 2012 Accepted 11 July 2012 Available online July 11 2012 Bombardier Aerospace’s high performance aircrafts and services set the utmost standard for the Aerospace industry. A case study in collaboration with Bombardier Aerospace is conducted in order to estimate the target cost of a landing gear. More precisely, the study uses both parametric model and neural network models to estimate the cost of main landing gears, a major aircraft commodity. A comparative analysis between the parametric based model and those upon neural networks model will be considered in order to determine the most accurate method to predict the cost of a main landing gear. Several trials are presented for the design and use of the neural network model. The analysis for the case under study shows the flexibility in the design of the neural network model. Furthermore, the performance of the neural network model is deemed superior to the parametric models for this case study. © 2012 Growing Science Ltd. All rights reserved.

Evolving fuselage designs by incorporating SHM technologies

AbstractResearch efforts at Bombardier Aerospace have investigated design constraints that need to be addressed when considering the design of a future unconventional fuselage concept. Using a composite design platform integrated with structural health monitoring (SHM) technologies, the design space is broadened and there are many more unknowns to investigate from our current knowledge of the subject to date. The principal idea is to identify structural zones and quantify stress levels in areas of concern, referred to as ‘hot-spots’, by integrating an SHM system at a conceptual design level. This new concept would require an assessment of benefits and detriments in order to evaluate the certification processes, impact on maintenance, operation, and ownership costs.The integration of an SHM system using onboard sensors introduces many challenges, such as the requirement for multiple sensors in the structure and additional systems weight. The investigation shows how the aircraft structural design would be impacted and how design, stress, supply-chain, manufacturing, and the systems departments need to be harmonised in order to design a feasible and integrated SHM-structural fuselage concept.

Bombardier throws down the gauntlet with CSeries airliner

Bombardier Aerospace says its CSeries will deliver a 20% fuel burn advantage, 15% lower operating costs and 25% lower maintenance costs compared to other aircraft in its class. The aircraft's low-weight airframe features extensive use of advanced structural materials, including composites in the wing, empennage, nacelle and rear fuselage. George Marsh reports on the project's progress so far.

How Industry Concepts of Concurrent Engineering Enhance Aircraft Design Education

Two student projects are described including the intended goals, the approaches taken, the tools used, and what was learned from the exercises. An international collaborative teaching protocol between Ecole Polytechnique de Montreal and the Royal Institute of Technology (KTH) was exercised in aircraft design education. Poignantly, a novel instructive design process using the analogue of contemporary concurrent engineering practices in industry was implemented. The idea was to strategically assign multi-disciplinary design tasks to each Partner University in accordance with their respective competencies. The university-industry coupling was initiated by request for proposals and corresponding marketing requirements and objectives produced by Bombardier Aerospace in Montreal, Canada. Two MATLAB TM-based tools were prominent in facilitating the capstone aircraft design projects. They included: Quick Conceptual Aircraft Research and Design, a computer-aided conceptual design engineering system; and TORNADO, a Vortex-Lattice code for computing aerodynamic characteristics. The result of the two exercises was found to benefit the participating industry, the educational establishments involved, and the students carrying out the projects.

Modelling of aircraft manufacturing cost at the concept stage

The work presented is concerned with the estimation of manufacturing cost at the concept design stage, when little technical information is readily available. The work focuses on the nose cowl sections of a wide range of engine nacelles built at Bombardier Aerospace Shorts of Belfast. A core methodology is presented that: defines manufacturing cost elements that are prominent; utilises technical parameters that are highly influential in generating those costs; establishes the linkage between these two; and builds the associated cost estimating relations into models. The methodology is readily adapted to deal with both the early and more mature conceptual design phases, which thereby highlights the generic, flexible and fundamental nature of the method. The early concept cost model simplifies cost as a cumulative element that can be estimated using higher level complexity ratings, while the mature concept cost model breaks manufacturing cost down into a number of constituents that are each driven by their own specific drivers. Both methodologies have an average error of less that ten percent when correlated with actual findings, thus achieving an acceptable level of accuracy. By way of validity and application, the research is firmly based on industrial case studies and practice and addresses the integration of design and manufacture through cost. The main contribution of the paper is the cost modelling methodology. The elemental modelling of the cost breakdown structure through materials, part fabrication, assembly and their associated drivers is relevant to the analytical design procedure, as it utilises design definition and complexity that is understood by engineers.

Corrosion Risk Assessment of Aircraft Structures

Abstract This paper presents a comprehensive summary of IAR/NRC research on risk assessment of aging aircraft structures in the presence of corrosion and fatigue. Extensive test data, especially for fuselage splices containing corrosion and multiple site fatigue damage (MSD) and coupons cut from service exposed aircraft lap joints, have been generated under previous projects. Based on these test data, an empirical stochastic crack growth model was first developed to analyze the probabilistic fatigue characteristics of the splices. Risk analysis was then performed on the fuselage splices using the computer codes PRISM (Bombardier Aerospace, Inc.) and PROF (United States Air Force). Holistic life assessment methodology (HLAM), which aims to quantify structural integrity in the entire life cycle by addressing the interaction effects of corrosion and fatigue, has advanced considerably during the past five years. Risk analysis based on HLAM was carried out on the fuselage splices. The analytical results, which were obtained at different stages, are compared with the test results. It is shown that corrosion in lap joints, even at the levels less than the typical maintenance limit (i.e., 10 % material loss), could significantly increase the risk level of structural failure.

CF-18 Wing Full-scale Fatigue Testing And Structural Certification

The Canadian Forces (CF) ordered 138 FIA-18 from McDonnell aircraft company (McAir)/Northrup for delivery starting 1982. The design was intended to last 6000 hours under severe US Navy usage. This life was determined by the manufacturer after conducting full-scale fatigue tests. These tests were required to certify the safe life of the F/A-l8 based on the USN operating conditions. However, the difference between the CF-18 usage and the usage on which the airframe was originally tested, in addition to these tests not considering structural modifications performed on production aircraft after completion of full-scale testing, have created some structural concerns and a need to do additional fullscale fatigue testing. The Canadian Forces and the Royal Australian Airforce (RAAF) are currently collaborating in the International Follow-On Structural Test Program (IFOSTP) to conduct a full-scale fatigue test for the CF-18. This paper will show a summary on the effort which is currently going on the FT245 full-scale fatigue testing of the CF-18 wing. The wing is being tested by the National Research Council of Canada (NRC) at the Institute of Aerospace Research (IAR) and technically supported by Bombardier Aerospace The fatigue test loads derivation process will be introduced, the test response and loading feedback monitoring through strain gauging of the entire wing and centre fuselage will be discussed, and the test inspection process for detectinglmonitoring growing fatigue cracks will be presented. The paper will also present the effort done in preparation for the structural certification of the CF18 wing. Transactions on Engineering Sciences vol 40, © 2003 WIT Press, www.witpress.com, ISSN 1743-3533

Metal spray tooling for composite forming

Thermal spraying methods have been mooted as a method of manufacturing tooling for many years and yet they have not made a significant in-road into this market. Generally, recent metal spraying research has focussed on the manufacture of small, high-pressure tools (for example, for automotive injection moulding tools). However, the metal spray process really lends itself to the manufacture of large tooling where it can compete more effectively against alternatives such as machining. The 3-year, £ 750k, IMI Spray Mould Programme, funded jointly by EPSRC (IMI) and the industrial partners: Airbus, BAE SYSTEMS, Bombardier Aerospace Shorts, A.T. Poeton, Rover Group, and Sulzer Metco, commenced in June 1997. The aim of this research is to develop a method of manufacturing tooling for composite aerospace components, particularly large primary structures over 15 m in length. This paper will present the results of this research programme, including technical data comparing both the technical and economic advantages of this novel approach to tool construction.

Influence of manufacturing tolerance on aircraft direct operating cost (DOC)

The influence of manufacturing tolerance on direct operating cost (DOC) is extrapolated from an engine nacelle to be representative of an entire aircraft body. Initial manufacturing tolerance data was obtained from the shop floor at Bombardier Aerospace Shorts, Belfast while the corresponding costs were calculated according to various recurring elements such as basic labour and overtime labour, rework, concessions, and redeployment; along with the non-recurrent costs due to tooling and machinery, etc. The relation of tolerance to cost was modelled statistically so that the cost impact of tolerance change could be ascertained. It was shown that a relatively small relaxation in the assembly and fabrication tolerances of the wetted surfaces resulted in reduced costs of production that lowered aircraft DOC, as the incurred drag penalty was predicted and taken into account during the optimisation process.

Business transformation, information technology and competitive strategies: learning to fly

‘Business transformation’ is an overarching concept encompassing a range of competitive strategies which organisations adopt in order to bring about significant improvements in business performance. These strategies include business process re-engineering, organisational development/learning, Total Quality Management and use of information technology. In this article different models of business transformation are explored. This is followed by a full case study analysis of how a leading aerospace company, Short Brothers (now known as Bombardier Aerospace—Shorts), have transformed themselves since privatisation from an organisation in crisis to a leading performer in their market sector. The findings identify the realities of business transformation and support the argument that true business transformation should be viewed as a multi-stage process which demands an integrated approach to the application of supporting competitive strategies.

Method of designing layered sound absorbing materials

A widely used model for describing sound propagation in porous materials is the Johnson–Champoux–Allard model. This rigid frame model is based on five geometrical properties of the porous medium: resistivity, porosity, tortuosity, and viscous and thermal characteristic lengths. Using this model and with the knowledge of such properties for different absorbing materials, the design of a multiple layered system can be optimized efficiently and rapidly. The overall impedance of the layered systems can be calculated by the repeated application of single layer impedance equation. The knowledge of the properties of the materials involved in the layered system and their physical meaning, allows to perform by computer a systematic evaluation of potential layer combinations rather than do it experimentally which is time consuming and always not efficient. The final design of layered materials can then be confirmed by suitable measurements. A method of designing the overall acoustic absorption of multiple layered porous materials is presented. Some aspects based on the material properties, for designing a flat layered absorbing system are considered. Good agreement between measured and computed sound absorption coefficients has been obtained for the studied configurations. [Work supported by N.S.E.R.C. Canada, F.C.A.R. Quebec, and Bombardier Aerospace.]

The Dynamics of Decentralization: Canadian Federalism and British Devolution

Contributors include Claude E. Forgot (C.E.F. Ganish Corporation), Jane Jensen (Universite de Montreal), Harvey Lazar (Queen's University), Kenneth Morgan (University of Wales), Sir George Quigley (Bombardier Aerospace), Richard Simeon (University of Toronto), Shorts Hugh Segal (Institute for Research in Public Policy), and Peter Stoyko (Queen's University).

Impact of aerodynamic surface tolerance on aircraft cost driver

The cost impact of aerodynamic tolerances on the wetted surface of an engine nacelle is considered. Manufacturing tolerance data were obtained from Bombardier Aerospace Shorts, Belfast, while the corresponding costs were calculated according to various recurring elements such as basic and overtime labour, rework, concessions, redeployment, etc., along with amortized non-recurrent costs due to jigs and tooling, machinery, etc. The cost—tolerance relations were modelled statistically so that the influence of tolerance change could be ascertained. It was found that relatively small tolerance relaxations resulted in significantly reduced costs of production but that there was a large variation in the sensitivity, at current levels. The resultant drag penalty was also predicted in conjunction with the cost—tolerance estimation to show that the operational cost effectiveness of the nacelle was increased by 0.33 per cent.