Textured surfaces with partially regular micro relief (PRMR) are reported to be an effective means to control lublication. It was found they are good wear debris trap and suppliers of lubricant directly to the actual friction area. Their tribological properties depend on the clearance between mating surfaces, relative slip speed, direction of motion. These parameters change the lubrication regime, and vice versa changing geometry of PRMR it is possible to predict and control lubrication regime for given conditions. Application of micro textured surface is prospective for high precision sliding units – valve slides of oil and hydraulic systems, faces of gear pump gears, ring-to-cylinder interface of aircraft reciprocating engines etc. providing high service life. On other side, changing texture parameters it is possible to stop the leakage of fluid through the gap, what may be efficiently utilized in aircraft non-contacting mechanical (hydrodynamic and hydrostatic) seals of gas compressors and gear mechanisms. This paper discloses some peculiarities of transition lubrication regimes for textured surfaces in lubricated contact.

Reliability evaluation is a key factor in serviceability and safety analysis of air vehicles. Structural health monitoring methods have grown to a degree of maturity in many industries. However, there is a challenging interest to tie in SHM with reliability assessment. In this respect, consideration of stochastic structural dynamics with SHM data and random loadings opens a new chapter in failure prevention. The current study focuses on the stochastic behavior of structures as a way to relate SHM data with reliability. In this respect, uncertain factors such as atmospheric turbulence, structural parameters, and sensor outputs are considered in the process of reliability assessment. Firstly, an experimental evaluation is conducted using a simple cantilevered beam. Subsequently, system identification is weaved in with a probability density evolution equation for calculating the reliability of a wing structural component. Numerical simulations demonstrate that structural reliability of a typical WSC can be effectively evaluated. The proposed scheme paves the way for new SHM research topics such as online life prediction and reliability based failure prevention.

In order to cover this goal, four quality indexes related to the airline industry, and two economic performance. In order to cover this goal, four quality indexes related to the airline industry, and two economic performance indicators, revenues and return on investment (ROI), have been considered. Data from American airline companies from 2006 to 2013 have been used to determine if airlines’ profitability increases when service quality improves. Considering the effects on airlines’ profitability, the results confirm the positive and significant influence of service quality on the ROI of the US airline companies. A non-significant effect was found for airline revenues in relation to quality No previous research in this area has been done so these findings could encourage airline companies to invest in quality, since this policy can have a positive return on their profitability.

The main problem of sea aquatorium monitoring is the surveillance of large areas of the sea surface and the presence of many moving ships with different parameters. A methodology for the optimization of a Remotely Piloted Aircraft’s (RPA) route is presented.

The flight dynamics and handling qualities of any flexible aircraft can be analysed within the Cranfield Aircraft Accelerated Loads Model (CA2LM) framework. The modelling techniques and methods used to develop the framework are presented. The aerodynamic surfaces were modelled using the Modified Strip Theory (MST) and a state-space representation to model unsteady aerodynamics. With a modal approach, the structural flexibility and each mode’s influence on the structure deflections are analysed. To supplement the general overview of the framework equations of motion, models of atmosphere, gravity, fuselage and engines are introduced. The AX-1 general transport aircraft model is analysed as an example of the CA2LM framework capabilities. The results showed that, according to the Gibson Dropback criterion, the aircraft with no control system lacks the stability and its longitudinal handling qualities are unsatisfactory. Finally, the steps for future developments of the CA2LM framework are listed within conclusions.

Even considering the current low accident rate in aviation, the anticipated growth in the number of airplanes in the air in the next decades will lead to an inadmissible rise in the number of accidents. These have been mostly attributed to human error and a misunderstanding of automation by the crew, especially during periods of high workload and stress in the cockpit. Therefore, increased safety requires not only advances in technology, but improved cockpit design including better human-machine interface. These cannot be achieved however, without considering some of the cognitive constructs that affect the behaviour of pilots in the cockpit. In fact, given its characteristics and public visibility, the flight deck of commercial jets is one of the most common arenas for the study of complex and skilled human performance. Here I present a literature review on the selected topics of workload, situation awareness, stress and automation in the cockpit, with the goal of supporting the development of new technologies.

The air separators are used to provide safe, clean and appropriate air to the helicopter’s engine. In this operational study, the separation process inside a Ranque-Hilsch air separator cleaning system has been investigated to analyze the impact of choosing the appropriate turbulence model for predicting the separation process inside the air separator. This research is directed towards presenting a computational fluid dynamic explanation performed on a counter-flow air separator using air at different magnitudes of air flow fraction and applying different turbulence models. In a numerical investigation of counter-flow air separator, air has been chosen and its vortex separation phe- nomenon has been analyzed as a function of flow fraction. Furthermore, a numerical analysis to compare the outputs of a seven equation RSM turbulence model applied for the study of vortex separation of a counter-flow air separator with some two-equation turbulence methods, namely, k-ε and k-ω model as well as LES has been presented. All of the turbulence numerical methods are seen to present and predict the same flow pattern inside an air separator, but, with various details. The results show that among the tested methods the RSM creates the most accurate separation pattern. The numerical results are validated by some available experimental data with good agreement.

The ionosphere is the region of the upper atmosphere and the study of the upper atmosphere has a significant role in monitoring, modeling and forecasting for satellite based navigation services. As India lies in a low latitude region, a more careful approach has to be taken to characterize the ionosphere due to the irregularities and equatorial anomaly conditions. In order to study the ionospheric temporal variations, a regional ionospheric model based on the Adjusted Spherical Harmonic Analysis (ASHA) is implemented. The results indicate that the ASHA model is one of the contenders for estimating ionospheric delays well for GNSS augmentation systems.

The gravity model is a method that is used by transportation researchers, airline network planners and analysts to explain how traffic is distributed between city pairs in correlation to the distance or travelling time between them, which as a result indicates the behaviour of travellers or the performance of the transport connection. How ever, the applicability of the model depends on the reliability of the results, which poses a major issue for researches. The major difficulty is to obtain comparable qualitative insights into the key parameters that are selected. This paper presents a possibility study for the use of the gravity model for regional route planning from the scientific point of view and suggests possibilities of gravity model calibration for airline network analysis including alternative methods for estimating the gravity potential of destinations and measurement of the influence of distance on the potential. The focus of the research is the ability to explain and forecast the development of regional air transportation routes in the commercial aviation network when there is a lack of recorded booking demand data.

The effect of miniflaps for increasing the L/D ratio and the lift coefficient has been studied on airliners as well as on UAV-s and wind turbines. For sailplanes the lift when Cl > 1.0 is of main interest. As the maximum wing loading of racing sailplanes reaches 60–62 kg/m2, it is necessary to achieve a high Cl max (1.7–1.8) in thermals. In this case the decrease in TAS caused by a high Cl max even compensates for the drop of the L/D ratio to a certain extent, as the climb speed will increase when the spiral flight radius diminishes in thermals. To bring the L/D to Cl > 1.0, a 2% chord miniflap at a 30° deflection angle was attached to the trailing edge of a Jantar-Standard 3 type sailplane wing (airfoil NN-8). In flight tests it was found that the miniflap increased the sailplane‘s Cl max to 1.35–1.66, i.e. by 23% (Re 1.0–0.92×106). At the same time the L/D ratio Cl increased by over 1.0. Especially good L/D improvement was noted with Cl at 1.13–1.19. In thermal Cl of 1.57–1.65 the roll control was good. At lower Cl < 1.0 values, the miniflap reduced the L/D ratio in comparison with a normal configuration.