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Aircraft are high value-adding and long-living assets, while aircraft cabins are expensive consumer products tailored to each customer. Vastly changing requirements and needs force aircraft holders regularly to instruct modifications in order to remain attractive on the market. Adaptations, modifications, and development of innovations are handled by multiple organizations, not by a central one like the aircraft’s manufacturer or owner. Although the Continuing Airworthiness Management Organization manages all aircraft instance-specific documents as required by aviation regulations, their format and types of management differ. Besides, not all information that arises during a parts design phase is included. That means, overall, the consistent model-based maintenance of data within all phases of PLM up to disposal is not guaranteed.

Threaded, potted inserts are commonly used as a standard connecting element for sandwich components, which are used for aircraft interior. Since they often offer the only detachable connection, they are used in very high quantities. To ensure a material bond between the inserts and the honeycomb structure, the joint is filled with adhesive. Despite the high number of inserts, this process is performed manually. Recent research has shown new approaches for automated gripping and placement of the inserts by an industrial robot that yield high potential for cost savings and increased productivity. Automated adhesive insertion, so-called potting, has not been considered so far but is an essential contribution to the full automation of the entire process chain. The amount of adhesive varies depending on the type of insert and its position on the honeycomb structure.

Current communication architectures in the aircraft cabin are mostly proprietary and limited to the boundaries of the diverging systems, i.e. existing cabin systems operate mostly isolated from each other. Modern system design, however, requires a shared communication platform in order to enable novel services by means of a contract-based data and information exchange. Data-driven predictive maintenance applications are one example for which the fundamentals are studied intensively, but its integration into a multi-system environment with respect to communication requirements is often neglected. As the aircraft cabin is a highly dynamic environment with changing air pressure, humidity, temperature, and flight attitude, context information is needed in order to get meaningful predictions for e.g. the Remaining Useful Life (RUL) of a system, component or item.

In the past, aircraft network design did not demand for information security considerations. The aircraft systems were simple, obscure, proprietary and, most importantly for security, the systems have been either physically isolated or they have been connected by directed communication links. The union of the aircraft systems thus formed a federated network. These properties are in sharp contrast with today’s system designs, which rest upon platform-based solutions with shared resources being interconnected by a massively meshed and shared communication network. The resulting connectivity and the high number of interfaces require an in-depth security analysis as the systems also provide functions that are required for the safe operation of the aircraft. This network design evolution, however, resulted in an iterative and continuous adaption of existing network solutions as these have not been developed from scratch.

The demand for higher production rates of large parts in aircraft industry requests more flexible manufacturing solutions. High-accurate mobile robots show a promising alternative in comparison with high-invest special machines. With mobile robot-based solutions processes can be executed simultaneously which increases the productivity significantly. However, the freedom of mobility results in insufficient positioning accuracy of these machines. Hence fast and accurate referencing processes are required to achieve cost-effectiveness and meet production tolerances. In this publication a Mobile Laser Tracker (MLT) system and a holistic approach for future manufacturing systems with mobile robots will be introduced and discussed.

For an “end-to-end passenger experience that is secure, seamless and efficient” the International Air Transport Association (IATA) proposes Near Field Communication (NFC) and a single token concept to be enablers for future digital travel. NFC is a wireless technology commonly utilized in Portable Electronic Devices (PEDs) and contactless smart cards. It is characterized by the following two attributes: a tangible user interface and secured short range communication. While manufacturers are currently adapting PED settings to enable NFC in the flight mode, the integration and use of this technology in aircraft cabins still remains a challenge. There are no explicit qualification guidelines for electromagnetic compatibility (EMC) testing in an aircraft environment available and there is a lack of a detailed characterization of NFC equipped PEDs.

The demand for higher production rates in aircraft industry requests more flexible manufacturing solutions. A bottleneck in production is the machining of large components by vast portal machines. Time-consuming referencing processes result in non-satisfying cost-effectiveness of these high-invest-machines. Mobile robot-based solutions are able to operate simultaneously which increases the productivity significantly. However, due to the limited workspace of robots, machining tasks have to be divided and long trajectories are separated in single overlapping segments. Thus high-accuracy referencing strategies are required to achieve desired production tolerances. In this publication different advanced optical reference strategies will be discussed taking the inhomogeneous behavior of a mobile robotic machining system into account.

Strong market growth, upcoming global competition and the impact of customer-requirements in aerospace industry demand for more productive, flexible and cost-effective machining systems. Industrial robots have already demonstrated their advantages in smart and efficient production in a wide field of applications and industries. However, their use for machining of structural aircraft components is still obstructed by the disadvantage of low absolute accuracy and adverse reaction to process loads. This publication demonstrates and investigates different methods for performance assessment and optimization of robot-based machining systems. For conventional Cartesian CNC machining systems several methods and guidelines for performance assessment and error identification are available. Due to the attributes of a common 6-axis-robot serial kinematics these methods of decoupled and separated analysis fail, especially concerning optimization of the system.

The aviation industry is facing major challenges due to increased environmental requirements that are driven by economic constraints. For this reason, guidelines like "Flightpath 2050", the official guide of European aviation, call for significant reductions in pollutant emissions. The concept of the More Electric Aircraft offers promising perspectives to meet these demands. A key-enabler for this concept is the integration of new technologies on board of the next generation of civil transportation aircraft. Examples are electro-mechanical actuators for primary and secondary flight controls or the fuel cell technology as innovative electrical energy supply system. Due to the high complexity and interdisciplinarity, the development of such systems is an equally challenging and time-consuming process.

The continuous need for improved high lift performance motivates the evaluation of innovative high lift systems. Single flap drive systems are possible solutions to implement novel functionalities for aerodynamic performance optimization. The previously mechanical coupling needs to be replaced by approved equivalent means. This directly results in high demands on control and monitoring of the multiple single drive systems in order to preserve a safe operation. In the context of the national German research project SysTAvio, strategies for a new concept of a multifunctional high lift system are investigated and presented in this paper. The conceptual system comprises four single flap surfaces, each driven by a local transmission system and powered by a local power control unit. This architecture requires an innovative control strategy for a safe operation of a single drive system as well as synchronous movement of multiple systems.

For the shift to more-electric aircraft systems, the system specific design paradigm has to be dissolved and the allocation of functions has to be reconsidered. Including more degrees of freedom within the architecture design process for aircraft systems could lead to beneficial architecture concepts. However, new methods for conceptual systems design are required, to cope with the significantly increasing number of potential architecture variations to be evaluated. Within this paper, the GENESYS methodology enabling the design and evaluation of numerous architecture variations will proposed. The methodology consists of several modules, each dedicated to a specific process step of conceptual aircraft system design. Initially, a method for the design-independent analysis of the aircraft level functions and the identification of requirements for the aircraft systems will be illustrated.

Fuel cell technology will play a decisive role in the process of achieving the ambitious ecological goals of the aviation industry. However, apart from its obvious environmental advantages, the integration of fuel cell technology into commercial aircraft represents a challenging task in terms of operational and economical aspects. Since fuel cell systems are currently exposed to an intense competition with well-established power sources onboard an aircraft, engineers are in pursuit of highly efficient and particularly lightweight fuel cell systems. Supported by model-based design in conjunction with elaborate optimization techniques this pursuit has led to highly specialized systems. These systems tend to use their components to full capacity, which typically implies marginal system robustness. In consequence, preliminary design studies propose fuel cell systems that are sensitive to partial faults, or even to the slightest deviation, or degradation of their components' behavior.

The All-Electric-Engine with only electrical power offtake is a main goal in aircraft system development. The use of electric-motor pumps instead of engine-driven pumps for powering the central hydraulic systems could be a part of this objective. Additionally, the concept would meet the incremental development strategy performed by the aerospace industry today and saves costs by using state-of-the-art hydraulic actuation technology. This paper describes a process for optimizing such systems regarding their architecture and design parameters. For this task a methodology for the hydraulic consumer allocation called OPAL is used and extended by an automatic power system sizing. Feasible allocations, called permutations, are determined on the basis of preliminary system safety assessments regarding multiple top failure events. In the next step an automated sizing of the permutations is performed based on simplified hydraulic load analyses.

The limitation of fuel entry into the oil sump of an internal combustion engine during operation is important to preserve the tribological properties of the lubricant and limit component wear. For observation and quantification of the effects leading to fuel entry, a highly sensitive and versatile measurement system is essential. While oil sampling from the sump followed by laboratory analysis is a common procedure, there is no system for automatic sampling of all the positions and fast online analysis of the samples. For the research project ‘Fuel in Oil’, a measurement system was developed especially for the described tasks. The system is placed next to the engine in the test cell. Sampling points are the target point of the fuel injector jet and the liner below, the oil sump and the crankcase ventilation system.

The high thermal stresses generated between the contacting surfaces of a multi-disc clutch system (pressure plate, clutch discs, plate separators and piston) due to the frictional heating generated during the slipping, is considered to be one of the main reasons of clutch failure for contact surfaces. A finite element technique has been used to study the transient thermoelastic phenomena of a multi-disc dry clutch. The results present the contact pressure distribution, the temperature evaluation and the heat flux generated along the frictional surfaces. Analysis has been completed using two-dimensional axisymmetric model to simulate the multi-disc clutch. ANSYS software has been used to perform the numerical calculation in this paper.

Due to a shift of the major aviation concerns to focus on enhancements of the successful programs instead of pushing their successors, the need for new methodologies for aircraft system architecture design emerges. Challenging the existing requirements and reconsidering the functions and their allocation could help to dissolve the system specific development paradigm and lead to beneficial architecture concepts. To help understand the mechanisms and boundary conditions of developing fault-tolerant systems, the first part of the paper gives an overview of the successive process of architecture design. The significant architectural design decisions and the concurrent safety assessment process are discussed. One crucial step in the design space exploration of future aircraft system architectures is the allocation of the consumers to the available power sources. Within the paper a methodology for the optimization of the power allocation for flight control systems is proposed.

A friction clutch is an essential component in the process of power transmission. Due to this importance, it's necessary to investigate the stresses and vibration characteristics of the rigid drive disc of clutch to avoid failure and obtain an optimal weight and cost. This work presents the numerical solution of computing the stresses and deformations during the steady-state period, as well as the vibration characteristics of the rigid drive disc of friction clutch. Furthermore, new models for rigid drive disc have been suggested. The response of the new suggested models have been compared to the classic model, the numerical results show that the stresses and vibration characteristics of rigid drive disc of clutch can be controlled by adjusting design parameters. They show as well that the suggested models improve the response of the friction clutch considerably. The ANSYS/WORKBENCH14 and SolidWorks 2012 have been used to perform the numerical calculation in this paper.

Most of failures in automotive friction clutches occur due to the excessive heat generated between the contact surfaces during the slipping period; for this reason, the accurate calculation of the heat generation during the slipping is considered an essential item in the successful design process to avoid the failures due to the high thermal stresses. A finite element technique has been used to study the temperature field, the heat generation and the contact pressure distribution when friction disc slides over the steel disc. Analysis has been completed using a three dimensional model to simulate the thermo-structural coupling in automotive clutches. ANSYS software has been used to perform the numerical calculation in this paper.

This paper focuses on the virtual integration and test approach used for the evaluation of an automation system developed for the multifunctional operation of fuel cells in commercial aircraft. In order to accomplish the virtual integration a model of the overall automation system is linked with a dynamic model of the complete fuel cell system. For this purpose a modeling approach for complex physical systems is described in this paper. During virtual testing various simulation runs are executed based on automatically generated test cases, which cover a complete flight mission. For this reason a flight mission is modeled as a Statechart that includes next to time- based flight phases also potential events and malfunctions (e.g. engine flame-out, cargo fire). An algorithm is described, which can find all possible state combinations including parallel event sequences.

The integration of fuel cell systems as an independent energy source (Auxiliary Power Unit, APU) requires enhanced aircraft cooling architectures. New environmental control systems and systems with an increased cooling demand are investigated in various research projects. Cooling system architectures can be designed which benefit from similar requirements, e.g. by using the same cooling loops. Additionally, an increased cooling demand makes the investigation of alternative heat sinks necessary. For detailed system investigations simulation studies are used. A model library has been created in Dymola/Modelica containing the necessary component models to simulate cooling systems. The used modeling approaches and main model information are presented in this article. In order to understand the basic system behavior a Design of Experiment (DOE) is useful. If only two or three parameters are considered, simulation studies can be performed for each possible parameter combination.