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  • Author: Jerzy Lewitowicz x
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Uncertainty and Dependability of the Risk Model Applicable to Operation of Aircrafts

The problem of risk appears as decisions are frequently made or must be made on the basis of results that are obtained for very scarce number of real cases, objects and short series. Therefore fundamentals for really crucial choices must be inferred from correlations that are burdened by a high degree of indeterminacy. On the other hand, risk should also be considered for such circumstances when assessments are performed under excessive certainty. This paper deals with a model of risk that is considered for the subsystem of aircraft maintenance and the subsystem of its operation where operational (fights) efficiency and safety of flights are the matters of crucial importance.

Abstract

The paper concerns an application of lightness factors in comparative analysis of strength properties of basic materials being applied in aeronautical structures – in a historical perspective. The use of lightness factors enables effective estimation how lighter will be the structural elements (of the same strength or stiffness) made from different kind of materials : traditional as well as advanced composites. It is quite easy to find the solution to the inverse problem, i.e. to estimate how differ will be stiffness or strength for the same mass of the structural elements. Very particular application of the lightness factors are noted in engineers calculations of composite gliders wing spars, where they appears as the materials constants and as structure loading factors as well. The paper presents some examples of application of the lightness factors in strength analysis of the composite shells applied in the shear webs of the wing spars, and refers to the design recommendations issued by German aviation authority (LBA).

Abstract

The paper concerns an application of lightness factors in comparative analysis of strength properties of basic materials being applied in aeronautical structures – in a historical perspective. The use of lightness factors enables effective estimation how lighter will be the structural elements (of the same strength or stiffness) made from different kind of materials : traditional as well as advanced composites. It is quite easy to find the solution to the inverse problem, i.e. to estimate how differ will be stiffness or strength for the same mass of the structural elements. Very particular application of the lightness factors are noted in engineers calculations of composite gliders wing spars, where they appears as the materials constants and as structure loading factors as well. The paper presents some examples of application of the lightness factors in strength analysis of the composite shells applied in the shear webs of the wing spars, and refers to the design recommendations issued by German aviation authority (LBA).

Abstract

The quality of being able to operate safely (S, in Polish - bezpieczność) and the quality of being hazard-prone (Z, in Polish - zagrożeniowość, zagrażalność), Z being the opposite of S, are important properties of any maritime vessel and/or aircraft, i.e. any engineering system/device (UT). The rates WS and WZ considered in terms of probability and remaining within the [0, 1] interval are measures of these properties. High value of WS enables the engineering system/device (UT) to be operated with the possibly maximum safety. The sum of WS and WZ is one (unity), whereas the product thereof satisfies the following condition: WS x WZ ≤ 1. The derived equation of indeterminacy points out to the fact that any increase in the value of WS by subsequent increments ΔWs, which makes the WS approach the limit of unity, demands ever greater amount of power and abilities, i.e. energy (expenses).

Abstract

This paper considered a problem of: the reliability of performance of a nosedive of a jet powered aircraft in the context of the ability of pilots trained on a simulator to reliably accomplish a combat mission. For research purposes, the manoeuvre of attack of a target with the nosedive, which is most commonly used by the pilots performing flights on different types of modern aircrafts, and the basic manoeuvre during aircrew training, both basic and advanced were assumed. The research was conducted on a flight simulator.

Safety of Operation and Maintenance Systems of Aircraft Fleet

The flight of on aircraft has been realzed I on operational subsystem. The operation of on aircraft and its safeability are determined for aircraft fleet the so-called flight safety. Aircraft operation and its safeability determine the flight safety of aircraft fleet. The flight safety can be modelled, condition diagnosed, put the procedures of genesis and prognosis. As the results of these activities the prevention treatments can be worked out. A aircraft safety, air system safety or air safety can be considered. Within the flight safety science.

Entomopter Maneuverability Exchanged by Deformations Control of Flexible Flapping Wings

In the background of preparing this paper lies our believe that transferring ideas from the more matured disciple like aircraft technology to emerging animal technology should be beneficial for the later one and vice-versa. One integrated idea, of special interest to both disciplines, is the active flexible wing concept. In this paper we developed aeroelastic analysis for a flexible wing for an imposed harmonic flapping motion about the root chord of the wing. A Matlab code was written based on the analysis. This code was used to find the average lift and thrust of a wing of known aerodynamic and structural properties.

Abstract

The paper defines the essence of durability characteristics of the designing structure of an airframe in terms of flight safety. Particular attention is drawn to one of the main factors influencing the durability characteristics of the airframe – diagnostics system for the health assessment of the airframe during the process of operation. The effectiveness of the use of integrated solutions to the structure of the airframe providing a continuous assessment of the technical condition is presented. Continuous diagnostics system integrated with the airframe, SHM, is classified as an intelligent solution. This paper presents a model of the behavior of one-type aircraft operating in the air operator’s fleet in terms of susceptibility to failure. Justified assumption in the description of this behavior, in the form of a “bathtub curve”. The analysis is supported by real data of failures. The benefits of using a continuous diagnostics system integrated with the airframe, SHM, is interpreted in relation to the classical approach with the use of non-destructive testing, NDT, for the three phases of the bathtub curve.

Abstract

In aeronautics, the question of maintaining the highest possible level of flight safety is the most crucial issue. This is the reason why the scientists, engineers, and aerospace/aviation engineering staff keep searching for ever newer and more reliable methods of increasing the safety level. Therefore, new methods - primarily nondestructive ones - to diagnose aircraft turbine engines are looked for. These methods are expected to prove useful for the real-time monitoring of actual health of the engine and its assemblies. The paper has been intended to outline the most recent methods of diagnosing aircraft turbine engines, including the computed tomography methods as applied to assess health/maintenance status of turbine blades, for the phase mapping of increments in the engine’s rotational speed, to diagnose health/maintenance status of the compressor’s 1st stage rotor blades in pure jets. Other methods discussed are, e.g. vibroacoustic and tribological ones

Abstract

Civilization is a state of human society during a particular period of time, conditioned with the degree to which the humans are able to control the nature; the total of already collected material goods, means of production and exploitation, suitable skills (know-how), and social institutions. It is processes of exploitation of engineered objects and natural resources of the Earth that closely and directly relate the economy, safety (widely understood) and environmental protection. Nowadays, as the development of technology has become a hectic process, too little attention is paid to safety. People die. The above outlined considerations can be summarized in the form of the following conclusion: Exploitation is an area that covers the art of many and various activities. It is a philosophy that puts all the fields of knowledge together. Therefore, it should be considered a separate line of science.