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Copyright of Transactions of Nanjing University of Aeronautics & Astronautics is the property of Editorial Department of Journal of Nanjing University of Aeronautics & Astronautics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of Nanjing University of Aeronautics & Astronautics is the property of Editorial Department of Journal of Nanjing University of Aeronautics & Astronautics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of Nanjing University of Aeronautics & Astronautics is the property of Editorial Department of Journal of Nanjing University of Aeronautics & Astronautics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of Nanjing University of Aeronautics & Astronautics is the property of Editorial Department of Journal of Nanjing University of Aeronautics & Astronautics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of Nanjing University of Aeronautics & Astronautics is the property of Editorial Department of Journal of Nanjing University of Aeronautics & Astronautics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of Nanjing University of Aeronautics & Astronautics is the property of Editorial Department of Journal of Nanjing University of Aeronautics & Astronautics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The increase in available data from sensors embedded in industrial equipment has led to a recent rise in the use of industrial predictive maintenance. In the aircraft industry, predictive maintenance has become an essential tool for optimizing maintenance schedules, reducing aircraft downtime, and identifying unexpected faults. Despite this, there is currently no comprehensive survey of predictive maintenance applications and techniques solely devoted to the aircraft manufacturing industry. This article is an in‐depth state‐of‐the‐art systematic literature review of the different data types, applications, projects, and opportunities for predictive maintenance in this industry. The goal of this review is to identify, and highlight the challenges and opportunities for future research in this field. This review found that the current focus of research is too biased towards aircraft engines due to a lack of publicly available data sets, and that greater automation is an important step to optimize aircraft maintenance to its full potential. [ABSTRACT FROM AUTHOR]

The Metal Powder Industries Federation has awarded the gerotor design with the "Powder Metallurgy Industry Landmark" distinction. The gerotor pump is a reliable and robust positive displacement pumping system that has been in use for over a century. The gerotor design, consisting of two moving components, has been widely used in various applications, from automotive to industrial pumps. The conventional press & sinter PM manufacturing process has greatly expanded the use of gerotors, with millions being produced annually for different industries. The gerotor's history dates back to the late 19th century, and it has since made significant contributions to the aircraft industry and other sectors. [Extracted from the article]

Scope of the article will cover analysis of special customs procedures and other facilitations that can be used in MRO business. The two research questions that are answered in the paper are: what customs procedures can be used, how they work and if those can reduce costs of MRO operations significantly. There are two research methodological approaches used in this article: qualitative and quantitative. Results show a great difference in savings between two variants, in which one would present a very basic level of special customs procedures usage and a variant in which all presented possibilities would be applied. Research results showed many possibilities for changes in the customs strategy of a company interested in evolving it and generating savings from many facilitations due to usage of special customs procedures as well as a compact explanation of how the application of a special procedures process looks. This article may be interesting for both: scientists and specialists working in the field of customs as well as for the companies working internationally with a lot of imported materials needed to perform work on an engine or aircraft. The authors' conclusion is that even small companies might learn a lot from the analysis given in this article, due to the fact that the knowledge gathered here can give a greater understanding of customs knowledge presented in this article, combined with knowledge about other taxes will give an extraordinary advantage on the market for companies in MRO, or a similar industry. [ABSTRACT FROM AUTHOR]

This paper investigates the utilization of differential thrust to help a commercial aircraft with a damaged vertical stabilizer in order to regain its lateral/directional stability. In the event of an aircraft losing its vertical stabilizer, the consequential loss of the lateral/directional stability and control is likely to cause a fatal crash. In this paper, an aircraft with a completely damaged vertical stabilizer is investigated, and a unique differential thrust-based adaptive control approach is proposed to achieve a stable flight envelope. The propulsion dynamics of the aircraft is modeled as a system of differential equations with engine time constant and time delay terms to study the engine response time with respect to a differential thrust input. The proposed differential thrust control module is then presented to map the rudder input to differential thrust input. Model reference adaptive control based on the Lyapunov stability approach is implemented to test the ability of the damaged aircraft to track the model aircraft’s (reference) response in an extreme scenario. Investigation results demonstrate successful application of such differential thrust approach to regain lateral/directional stability of a damaged aircraft with no vertical stabilizer. Finally, the conducted robustness and uncertainty analysis results conclude that the stability and performance of the damaged aircraft remain within desirable limits and demonstrate a safe flight mission through the proposed adaptive control methodology. [ABSTRACT FROM AUTHOR]

This study analyzes two types of aircraft offered to the industry by two different manufacturers on an identical route and trajectory for commercial aviation and the noxious emissions resulting from equipping these aircraft with the most frequently used engine combinations today. The research covers the most recent Base of Aircraft Data (BADA v4.2_1), the Aircraft Noise and Performance (ANP v2.3), and the ICAO Engine Emission Database (254-ICAO EDDB25/FOCA) based integrated aircraft noise and emissions modelling platform (IMPACT) developed by EUROCONTROL. The striking findings in fuel consumption and emissions of four different scenarios during identical flight operations are detailed. The research presents the application of a systematic aircraft-engine pair decision mechanism for investigators, scientists, airline operators, policy analysts and legislators, in accordance with a comprehensive computer simulation method that consistently acknowledges the fuel consumption and emissions analysis of aircraft-engine parings. • Addressed the research gap in the selection of aircraft-engine pairs. • Comparing fuel consumption and amount of emissions of aircraft-engine pairings. • Revealing diversity fuel consumptions of same body aircraft with various engines. • Demonstrating the significance of aircraft-engine pair selection. • Promoting efficient and sustainable aircraft-engine parings for green airlines. [ABSTRACT FROM AUTHOR]

• The design of composite engine cover of light aircraft was roughly presented. • Mechanical properties of applied composite were experimentally obtained. • Failure simulations of composite specimens were conducted in Helius PFA © software. • Numerical structural analysis of engine cover was conducted. • Conducted analyses determined the final design of the engine cover. The aircraft industry is a leading industry in terms of the implementation of new materials and technologies. In the development of a light aircraft several different materials were considered for the engine cover design and the final decision was to select a composite material. Part of the research performed on the cover design is presented in this paper. The composite test specimens were produced and mechanical properties were investigated in the tensile and three-point flexural tests according to the required standards. The comparison of experimentally and numerically obtained mechanical properties showed good agreement, which led to the design, verification and manufacturing of the complex-shaped engine cover without costly and demanding tests. It was considered that numerical simulations of the engine cover performance under different loading conditions yielded realistic results, therefore experimental verification was excluded. The flight tests proved the predicted behavior, thus verifying the design methodology presented in this paper. [ABSTRACT FROM AUTHOR]

Accidents in twin-engine aircraft carry a higher risk of fatality compared with single engine aircraft and constitute 9% of all general aviation accidents. The different flight profile (higher airspeed, service ceiling, increased fuel load, and aircraft yaw in engine failure) may make comparable studies on single-engine aircraft accident causes less relevant. The objective of this study was to identify the accident causes for non-commercial operations in twin engine aircraft. A NTSB accident database query for accidents in twin piston engine airplanes of 4–8 seat capacity with a maximum certified weight of 3000–8000 lbs. operating under 14CFR Part 91 for the period spanning 2002 and 2012 returned 376 accidents. Accident causes and contributing factors were as per the NTSB final report categories. Total annual flight hour data for the twin engine piston aircraft fleet were obtained from the FAA. Statistical analyses employed Chi Square, Fisher’s Exact and logistic regression analysis. Neither the combined fatal/non-fatal accident nor the fatal accident rate declined over the period spanning 2002–2012. Under visual weather conditions, the largest number, n = 27, (27%) of fatal accidents was attributed to malfunction with a failure to follow single engine procedures representing the most common contributing factor. In degraded visibility, poor instrument approach procedures resulted in the greatest proportion of fatal crashes. Encountering thunderstorms was the most lethal of all accident causes with all occupants sustaining fatal injuries. At night, a failure to maintain obstacle/terrain clearance was the most common accident cause leading to 36% of fatal crashes. The results of logistic regression showed that operations at night (OR 3.7), off airport landings (OR 14.8) and post-impact fire (OR 7.2) all carried an excess risk of a fatal flight. This study indicates training areas that should receive increased emphasis for twin-engine training/recency. First, increased training should be provided on single engine procedures in the event of an engine failure. Second, more focus should be placed on instrument approaches and recovery from unusual aircraft attitude where visibility is degraded. Third, pilots should be made aware of appropriate speed selection for inadvertent flights in convective weather. Finally, emphasizing the importance of conducting night operations under instrument flight rules with its altitude restrictions should lead to a diminished proportion of accidents attributed to failure to maintain obstacle/terrain clearance. [ABSTRACT FROM AUTHOR]

In the aircraft manufacturing industry, drilling hole inspection is a vital task for the noise reduction ability and the aircraft structure stability. Due to the complexity of the inner surface of the engine nacelle, inspecting drilling holes of a small size and a large number is fairly challenging. In this paper, we propose a framework for automatic hole inspection on composite flat parts. The raw data of traditional 3D laser scanning usually contain considerable noise and outliers, which has a great influence on tiny hole inspection. First, to perform measurement efficiently and to get raw data of good quality, we design a measurement platform to perform automatic measurement on a preset path. Instead of applying common boundary detection methods, we design a method to detect boundary points by evaluating the boundary possibility of each point, which is more likely to detect the points on a real hole boundary than noise. Based on the characteristics of laser scanning data, we then combine an effective algebraic circle fitting method with an iterative fitting strategy and develop a robust circle fitting method. The improved circle fitting method is capable of estimating a circle closest to the ground truth. Experiments demonstrate that our fitting method performs better than other common fitting methods for comparison under both synthetic and real scanning data. • An automatic inspection framework for tiny holes of composite material is proposed. • A measurement platform is designed to collect 3D point clouds of tiny holes. • A probability guided method is designed to detect boundary points on hole edge. • An iterative circle fitting algorithm for error reduction is proposed. [ABSTRACT FROM AUTHOR]

Article is related to the aspect of the introduction of biofuels to power turbine aircraft engines. The paper presents the current trends in the use of alternative fuels in aviation and the problems connected with the introduction of hydrocarbon biocomponents. It is pointed to the need to take research and implementation works in the field of the subject, also in Poland. [ABSTRACT FROM AUTHOR]

The optimized profile descent is an example of one of the many NextGen technologies under development to modernize and increase the efficiency of the national airspace system. The first publicly charted optimized profile descent procedure was implemented at Los Angeles International Airport in December 2007. This new flight procedure was designed so that aircraft could conduct arrival and approach operations with the engines remaining at or near minimum idle power settings; thereby, saving an average of 25 gal of jet fuel per flight when compared to the various aircraft types conducting an arrival and approach along the same lateral path at Los Angeles International Airport. This optimized profile descent translates into annual reductions of approximately 2,000,000 gal of jet fuel and 41,000,000 lb of carbon dioxide emissions. Given the positive environmental benefits of an optimized profile descent, there are several projects underway to increase the use of environmentally friendly arrival procedures within the national airspace system. The aforementioned achievement at Los Angeles International Airport has motivated and enabled new optimized profile descent procedure designs for Atlanta, Miami, Charleston, and Phoenix. [ABSTRACT FROM AUTHOR]

A method for assessing the impact of vehicle technologies and new aircraft concepts at the fleet level is presented. Various aspects of the method constitute a departure from standard practice intended to address known shortcomings and advance the state of the art. In particular, an operational activity growth routine is implemented where operational sets are grown to match top-level and airport-level forecasts that are fully balanced for all origin-destination airport pairs. The proposed approach also features a novel fleet evolution scheme where replacements are devised on the basis of mission capabilities for aircraft types rather than on seat classes, and the retirement of aircraft is applied to models introduced beyond the reference year. Surrogate models of fuel burn are regressed from gold-standard modeling tools and are shown to be suitable for system-wide assessments on the basis of model representation accuracy. Fleet assessment results are shown for various technology introduction and growth scenarios and indicate that an introduction of NASA vehicle technologies across the fleet in 2025 can yield up to 436.05 x 109 kg of fuel savings through 2050, or up to 94.6 million additional operations for that same period assuming a 2050 total fuel-burn cap at 2006 levels. [ABSTRACT FROM AUTHOR]

The article discusses the problem of noise pollution during the takeoff and landing of aircrafts. It mentions that a new method has been proposed for the detection of spinning modes using a single sensor. It also talks about several topics including in-duct circular microphone arrays, spinning modes and noise source of turbofan engine which generates between rotating fan and nearby stator vanes.

Purpose - The purpose of this paper is to introduce parametered modeling technology for the civil aircraft engine fan blade, to design the fan blade rapidly and accurately. Design/methodology/approach - The entire fan blade consists of three crucial parts: blade airfoil, tenon and airfoil root. Blade airfoil with a free surface feature is formed through the blade profiles from the hub to tip in the radial direction. The non-uniform rational basis spline (NURBS) is utilized to describe the blade profile. The geometry model of fan blade tenon is generated by extruding the sketch of the tenon. And the fillet section is designed to achieve the smooth transition of the up surface and the bottom surface of the blade root. Furthermore, the fan blade of a typical commercial engine is redesigned by the above method. Findings - The stress analysis of the fan blade shows that the fan blade model designed in this work is reasonable. Originality/value - The parametered fan blade model is presented on the basics of feature-based modeling technology. [ABSTRACT FROM AUTHOR]

We apply eigenstructure assignment to the design of a flight control system for a wind tunnel model of a tailless aircraft. The aircraft, known as the innovative control effectors (ICEs) aircraft, has unconventional control surfaces plus pitch and yaw thrust vectoring. We linearize the aircraft in straight and level flight at an altitude of 15,000 feet and Mach number 0.4. Then, we separately design flight control systems for the longitudinal and lateral dynamics.We use a control allocation scheme with weights so that the lateral pseudoinputs are yaw and roll moment, and the longitudinal pseudoinput is pitching moment. In contrast to previous eigenstructure assignment designs for the ICE aircraft, we consider the phugoid mode, thrust vectoring, and stability margins. We show how to simultaneously stabilize the phugoid mode, satisfy MIL-F-8785C mode specifications, and satisfy MIL-F-9490D phase and gain margin specifications. We also use a cstar command system that is preferable to earlier pitch-rate command systems. Finally, we present simulation results of the combined longitudinal/lateral flight control system using a full 6DOF nonlinear simulation with approximately 20,000 values for the aerodynamic coefficients. Our simulation includes limiters on actuator deflections, deflection rates, and control system integrators. [ABSTRACT FROM AUTHOR]

Crossflow heat exchangers play a significant role in the operation of an aircraft's environmental control system (ECS). The bleed air supplied by an aircraft engine, at high pressure and high temperature, requires regulation and control in order to be used for various pneumatic services. In the present investigation, the transient temperature response of crossflow plate-and-fin ECS heat exchangers, having a large core capacity with both fluids unmixed, is investigated numerically and experimentally for perturbations experienced in temperature. A non-linear lumped model of crossflow heat exchangers with a state-space solution valid for equal fluid velocities is derived and evaluated, in terms of fluid placement and number of lumps (sections) required. Dependency of the heat transfer coefficient on flowrates is incorporated in the dynamic modelling of the heat exchanger. Two models are derived, and the variation of the mean exit temperatures of both fluids with time is compared for the two alternative models, with consideration of the number of transfer units and heat capacitance rate ratios. One model requires axial lumping of the primary surface alone, as done in most of the existing models, and the second involves incorporating the effect of secondary surfaces (fins) on the heat exchanger transient performance. To quantify the importance of modelling the fins, a comparison of both simulation models with experimentally obtained data from a physical model is presented. By including fins and complex non-linearities in modelling of the ECS heat exchangers, a precise representation of the heat exchanger dynamics and accurate temperature responses are predicted. The model developments reported in this article can lead to improved aircraft ECS design and optimization. [ABSTRACT FROM AUTHOR]

Problems of high technological interest, for example the development of gas turbine engines, span disciplinary, and often organizational, boundaries. Although collaboration is critical in advancing the technology, it has been less a factor in gas turbine research. In this paper it is proposed that step changes in gas turbine performance can emerge from collaborative research endeavors that involve the development of integrated teams with the needed range of skills. Such teams are an important aspect in product development, but they are less familiar and less subscribed to in the research community. The case histories of two projects are given to illustrate the print: the development of the concept of "smart jet engines" and the Silent Aircraft Initiative. In addition to providing a capability to attack multidisciplinary problems, the way in which collaboration can enhance the research process within a single discipline is also discussed. [ABSTRACT FROM AUTHOR]

We address some topical problems of dynamics, strength, and reliability of aircraft engines. Solving these problems provides cost reduction of the engine development, testing, and operation. [ABSTRACT FROM AUTHOR]

The next generation aircraft engines are designed to be lighter and stronger than engines currently in use by using carbon fiber composites. In order to certify these engines, ballistic impact tests and computational analyses must be completed, which will simulate a “blade out” event in a catastrophic engine failure In order to computationally simulate the engine failure, properties of the carbon fiber and resin matrix must be known. When conducting computer simulations using a micromechanics approach, experimental tensile, compressive, and shear data are needed for constitutive modeling of the resin matrix material. The material properties of an Epon E862 epoxy resin will be investigated because it is a commercial 176°C (350°F) cure resin currently being used in these aircraft engines. These properties will be measured using optical measurement techniques. The epoxy specimens will be tested in tension, compression and torsional loadings under various strain rates ranging from 10-5 to 10-1 s-1 and temperatures ranging from room temperature to 80°C. To test the specimens at high temperatures, a specialized clear temperature chamber was used. The results show that the test procedure developed can accurately and quickly categorize the material response characteristics of an epoxy resin. In addition, the results display clear strain rate and temperature dependencies in the material response. [ABSTRACT FROM AUTHOR]

Abstract: The failures of T-ducts made of Ti A40 with 50mm in diameter and 0.52mm in thickness, used in the pneumatic system of a commercial aircraft, are examined as part of a research program aimed to improve the development of such systems. The investigation included the fractographic analysis of the burst parts, microstructure and internal duct surface observations and mechanical tests performed in samples taken from the failed ducts and from unused material. The failed duct fracture surfaces showed typical features of transgranular fatigue cracking. Delamination and oxide particle deposits were found in their internal surfaces. Tensile and fatigue tests revealed some effects of aging, but with no evidence of embrittlement. The fracture mechanisms were the same for the failed ducts and for the unused material. The internal surface damage, associated to the geometry of the duct and to the solid-solution hardening increases the local stress concentration. These facts suggest that cracks had initiated at multiple sites around the inside surface, so that further increments of cracking occurred on subsequent cyclic pressurization during service life until the occurrence of sudden final fast fracture. [Copyright &y& Elsevier]

This paper discusses some theoretical and experimental issues related to the active control of buzz-saw tones radiated from an aircraft engine inlet at takeoff. Buzz-saw tones occur when the rotor tip speed becomes supersonic. It arises due to the formation of shocks at the blade tips, which then propagate non-linearly along the engine duct. Buzz-saw noise comprises a series of tones harmonically related to the shaft rotation frequency (Engine Orders). Moreover, it has been shown that the noise at each Engine Order comprises just one single spinning mode. Whilst there has been considerable work aimed at assessing the feasibility of active control for reducing the tones due to rotor - stator interaction, buzz-saw noise has been overlooked. This is surprising given the low frequencies at which Buzz-Saw noise occurs, and its simple modal content, which both suggest that buzz-saw noise is particularly suited to active control. This paper describes various control strategies for reducing buzz-saw noise. The paper concludes with the results of a laboratory experiment aimed at demonstrated experimentally the effectiveness with which a single spinning mode, characteristic of an EO = 3 buzz-saw tone, can be controlled. Reductions in excess of 14dB are reported at some frequencies. [ABSTRACT FROM AUTHOR]

Bell Boeing has developed an aircraft that takes off and lands like a helicopter but flies like a fixed-wing turboprop. Called the V-22 Osprey, the aircraft features a tilt-rotor design that is achieved by gradually rotating the two engines mounted at the ends of the wings. The Osprey offers twice the speed, three times the payload and five times the range of helicopters. It can also fly more than twice as high as most helicopters, which means that, coupled with its greater speed, it is less susceptible to threats from the ground. With its combination of range and vertical take-off and landing capabilities, the Osprey is naturally an attractive investment for the US Navy. [ABSTRACT FROM AUTHOR]

Abstract: Advanced aircraft engine development in recent years has dictated increased rotational speeds with the consequence of increased mechanical stress requirements for rolling element bearings. A vast amount of heat is rejected which results in high oil scavenge and bearing metal temperatures. A ball bearing and its associated chamber from an RB199 turbofan Engine were used in an experimental investigation to determine the impact of several operating parameters on the scavenge and bearing race temperatures. The test bearing was a 124 mm PCD ball bearing with a split inner-ring employing under-race lubrication by two individual jets providing oil through each half of the inner-ring. The bearing run over a wide range of D times N (DN) values ranging from to with D the bore diameter of the bearing. The direction of the oil ingestion in the bearing (for or against the direction of the axial load) was found to have a considerable effect to the oil distribution and consequently to the heat generation in it. A significant reduction in the heat to oil was achieved when the oil was fed at certain proportions (ratio) by the two nozzles. Heat to Oil and Outer ring metal temperature correlations which consider the influence of the direction of oil ingestion relative to the direction of the axial load have been developed and compared to test results. This work is part of the European Research programme Brite Euram ATOS (Advanced Transmission and Oil Systems). [Copyright &y& Elsevier]

Bolted joints are used at numerous locations in the rotors and carcass structure of modern aircraft turbine engines. This application makes the design criteria and process substantially different from that used for other types of machinery. Specifically, in addition to providing engine alignment and high-pressure gas sealing, aircraft engine structural joints can operate at high temperatures and may be required to survive very large applied loads which can result from structural failures within the engine, such as the loss of a fan blade. As engine bypass ratios have increased in order to improve specific fuel consumption, these so-called "Ultimate" loads increasingly dominate the design of bolted joints in aircraft engines. This paper deals with the sizing and design of both bolts and lever flanges to meet these demanding requirements. Novel empirical methods, derived from both component test results and correlated analysis have been developed to perform strength evaluation of both flanges and bolts. Discussion of analytical techniques in use includes application of the LS-DYNA™ code for modeling of high-speed blade impact events as related to bolted joint behavior. [ABSTRACT FROM AUTHOR]

The unsteady vortex lattice method is used to model the oscillating plunging, pitching, twisting, and flapping motions of a finite-aspect-ratio wing. Its potential applications include design and analysis of small unmanned air vehicles and in the study of the high-frequency flapping flight of birds and other small flyers. The results are verified by theory and, in the plunging and pitching cases, by experimental data. The model includes free-wake relaxation, vortex stretching, and vortex dissipation effects and is implemented using object-oriented computing techniques. The results show that the method is capable of accurately simulating many of the features of complex flapping flight. [ABSTRACT FROM AUTHOR]

This paper examines the progress in aircraft and aircraft engines from the standpoint of the role that better materials and processing has played. Such progress includes the relatively recent transformation of the aircraft industry from purely performance driven products to products that are driven by customer value. It is demonstrated that advances in materials and processing technology and understanding has enabled much of the progress that has been made since the inception of manned, heavier than air flight. The recent constraints of cost, as determined by customer value, have changed the way new materials are introduced and these trends appear to be the new paradigm for the aircraft and aircraft engine industry.While the focus of this paper is aircraft and aircraft engines, the broader focus is on the role of materials in creating lightweight structures. There are examples used in this paper that are relevant to automotive applications once they are adjusted for cost. This matter is briefly discussed at the end of the paper. [Copyright &y& Elsevier]