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This paper aims to improve the alignment accuracy of large components in aircraft assembly and an evaluation algorithm, which is based on manufacture accuracy and coordination accuracy, is proposed.

With relative deviations of manufacturing feature points and coordinate feature points, an evaluation function of assembly error is constructed. Then the optimization model of large aircraft digital alignment is established to minimize the synthesis assembly error with tolerance requirements, which consist of three-dimensional (3D) tolerance of manufacturing feature points and relative tolerance between coordination feature points. The non-linear constrained optimization problem is solved by Lagrange multiplier method and quasi-Newton method with its initial value provided by the singular value decomposition method.

The optimized postures of large components are obtained, which makes the tolerance of both manufacturing and coordination requirements be met. Concurrently, the synthesis assembly error is minimized. Compared to the result of the singular value decomposition method, the algorithm is validated in three typical cases with practical data.

The proposed method has been used in several aircraft assembly projects and gained a good effect.

This paper proposes a method to optimize the manufacturing and coordination accuracy with tolerance constraints when the postures of several components are adjusted at the same time. The results of this paper will help to improve the quality of component assemblies.

The purpose of this paper is to analyze the effects of condition-based maintenance based on unscheduled maintenance delays that were caused by ATA chapter 21 (air conditioning). The goal is to show the introduction of condition monitoring in aircraft systems.

The research was done using the Airbus In-Service database to analyze the delay causes, delay length and to check if they are easy to detect via condition monitoring or not. These results were then combined with delay costs.

Analysis shows that about 80 percent of the maintenance actions that cause departure delays can be prevented when additional sensors are introduced. With already existing sensors it is possible to avoid about 20 percent of the delay causing maintenance actions.

The research is limited on the data of the Airbus in-service database and on ATA chapter 21 (air conditioning).

The research shows that delays can be prevented by using existing sensors in the air conditioning system for condition monitoring. More delays can be prevented by installing new sensors.

The research focuses on the effect of the air conditioning system of an aircraft on the delay effects and the impact of condition monitoring on delays.

Aircraft Design has been taught at the College of Aeronautics since 1946. The course is at postgraduate level and is of two years' duration. In the first year the students are given three exercises in component design which aim to teach a logical approach and the fundamentals of the subject. During the second year each student works as a member of a team engaged in the design of a complete aircraft, which is chosen to be of a type currently being investigated by industry. The project aircraft invariably incorporates experimental features and the design work is therefore of the nature of research.

The astronomical costs of poor reliability in both military and civil aircraft have led to increased efforts by designers and operators to improve reliability. One of the most powerful ways of doing this is to examine the good and bad points of current aircrafts' performance to see where improvements may be made. This process is heavily dependent on the quality of reliability information available to the industry.

Europe has adopted Flight Path 2050 (FP 2050) challenge with an objective of 90 per cent of the travelers being able to reach door-to-door European destinations within 4 hours by 2050. The aim can be achieved by reliable, well-organized small aircraft transport (SAT). Analysis of the currently operating small aircraft operational reliability data will support the development of future aircraft designs as well as reliability and safety requirements necessary for commercial operations.

The paper provides results of a statistical analysis of small aircraft current operations based on the reported events contained in the Database named European Coordination Centre for Aviation Incident Reporting Systems database. It presents identified safety indicators and focuses particularly on those related to the aviation technology.

It has been found that certain airframe and powerplant systems have the biggest influence on flight safety.

Multidisciplinary analysis of the operational and aircraft components reliability data will help in a proper preparation of the SAT supporting facilities, a design process of new aircraft and improvements of the existing airframe and powerplant systems.

Presented results are valuable for further developments of the statistical tools facilitating new product introduction.

A composite aircraft comprising two component aircraft capable of separate flight mounted one on top of another and initially connected together by releasable locking means so as to take off, fly and land as a single unit, has the wings of its upper component formed of a profile and aspect ratio of appreciably wider angular range between the angle of no lift and the angle of maximum lift than the corresponding angular range of the profile and aspect ratio employed for the wings of the lower component. As the speed of the composite craft increases the proportion of the lift taken by the wings of the upper component increases and that of the lower component diminishes until a speed is reached at which a force is available for ensuring the safe separation of the components when the locking means are released, without the necessity of adjusting the lift coefficient of the wings of the upper component. The Fokker F VII or Göttingen 387 wing section may be employed on the upper component and the R.A.F. 15 or R.A.F. 34, or according to the Provisional Specification R.A.F. 31, for the lower component. Alternatively the angular range of the wings of the upper component may be increased by the use of fixed or adjustable slots, in which case the R.A.F. 15 or R.A.F. 31 wing section may be used, or the wings of the lower component may have initially depressed flaps which are raised automatically or mechanically as the speed increases so as to reduce their angular range. The invention may be combined with the means for adjusting the lift coefficient of the wings of the upper component described in Specification 400,292 in which case the difference in the angular range may be less or the amount of adjustment provided for may be diminished. The releasing means described in Specifications 400,292 and 402,997 may be incorporated.

The purpose of this study is to investigate the influence of the technical and operational specifications of the Small Aircraft Transport System (SAT/SATS) to the achieved safety level.

Safety estimation was made with the use of mathematical model of safety of light aircraft in commercial operations developed on the basis of Federal Aviation Administration (FAA) data. The analysis was conducted for two different SATS business models based on Direct AiR Transport (DART) concept. It allowed for the investigation of the impact of technical specifications of the aircraft included into the SATS fleet as well as the selected elements of the applied business model on SATS safety level.

It was found that the proposed changes to DART system resulted in a significant improvement of safety. Mean Time Between Incidents and Accident (MTBIA) increased by 200 per cent. Additionally, the introduced alterations impacted the weights of particular domains and pilot’s error became less critical than the technical reliability.

It was shown that the application of new requirements influences both the safety level and the cost of operation, which was demonstrated within the ESPOSA and DART projects. Additionally, it was indicated that further effort to improve the light aircraft safety is absolutely necessary.

Originality consists in combining in one mathematical model both the aircraft configuration and the rules for business operation. Optimization of selected parameters of the system leads to a significant reduction in the accident number and to keeping the cost increment at a reasonable level. It was also found that the resulted improvement sometimes cannot be sufficient to consider a small aircraft operation fully safe, mainly owing to the numerous restrictions because of its small weight and loading capacity.

To review the most commonly used mechanical surface enhancement (MSE) techniques and their applications available in aerospace industry.

A brief description of each technique, as well as advantages and disadvantages over other techniques are given. The effects of those techniques on the surface characteristics and service properties of treated components are summarised. Finally, the applications of such techniques in the aerospace industry are presented with descriptive illustrations.

Provides a know‐how information and also comparison of techniques. Guides researchers and engineers to proper and appropriate use of each technique for relevant case or application.

The list of techniques can be extended to a wider range which may perhaps include specific and special purpose surface enhancement methods. The applications given in the paper are mainly industrial examples of such techniques which may reduce its usefulness in academia.

A very useful source of information and reference for companies and engineers working in repair and production technologies of aerospace components, and also a valuable guidance for researchers and academia or for those who are intending to make a research on surface enhancement technologies.

This paper introduces the most commonly used MSE techniques and their effects on the service properties of aerospace components, and provides a practical help and information for people in the industry and academia.

The modern helicopters are designed with maximum serviceability and long life expectancy to ensure minimum life cycle cost. The purpose of this paper is to present a framework to incorporate the customer requirements on reliability and maintainability (R&M) parameters into the design and development phase of a contemporary helicopter, and to discuss the way to capture operational data to establish and improve the R&M parameters to reduce life cycle cost.

From the analysis, it is established that the reliability and maintainability cost is the major contributor to the life cost. The significant reliability and maintainability parameters which influence R&M cost are identified from analysis. The operational and design data of a contemporary helicopter are collected, compiled and analyzed to establish and improve the reliability and maintainability parameters.

The process depicted in the paper is followed for a contemporary helicopter and substantial amount of life cycle cost reduction is observed with improvement of R&M parameters.

The benefits of this methodology not only reduce life cycle cost but also improve the availability/serviceability through less failure and less time for scheduled maintenance. The methodologies also provide the reliability trends indicating potential area for design improvement.

The proposed approach assists asset managers to reduce the life cycle costs through improvement of R&M parameters.

Smiths Industries Aerospace (SI) offers a multi‐aircraft capable generic health and usage monitoring system (GenHUMS) using field proven, off‐the‐shelf, airborne and ground‐based technology. The UK Ministry of Defence (MoD) has selected the GenHUMS for the Chinook aircraft with additional options for Puma, Sea King and Lynx aircraft. The GenHUMS provides all conventional HUMS functionality, and incorporates key innovation in the areas of rotor track and balance, failure detection, flight regime recognition, alert generation, system configurability, and user interface. The architecture is unique in that all required airborne data acquisition and processing, including crash survivable cockpit voice and flight data recording, are combined in a single line replaceable unit. This architecture significantly reduces space, weight and power requirements and results in the highest reliability, least risk, lowest life cycle cost, HUMS known today. Fixed and portable PC‐based HUMS ground stations provide configurable, user friendly, data extraction and analysis capabilities.