Mariusz Zieja

A Model for Service Life Control of Selected Device Systems

Abstract This paper presents a way of determining distribution of limit state exceedence time by a diagnostic parameter which determines accuracy of maintaining zero state. For calculations it was assumed that the diagnostic parameter is deviation from nominal value (zero state). Change of deviation value occurs as a result of destructive processes which occur during service. For estimation of deviation increasing rate in probabilistic sense, was used a difference equation from which, after transformation, Fokker-Planck differential equation was obtained [4, 11]. A particular solution of the equation is deviation increasing rate density function which was used for determining exceedance probability of limit state. The so-determined probability was then used to determine density function of limit state exceedance time, by increasing deviation. Having at disposal the density function of limit state exceedance time one determined service life of a system of maladjustment. In the end, a numerical example based on operational data of selected aircraft [weapon] sights was presented. The elaborated method can be also applied to determining residual life of shipboard devices whose technical state is determined on the basis of analysis of values of diagnostic parameters.

Information systems as a tool for supporting the management of aircraft flight safety

The article discusses the issue of air traffic safety in the context of aircraft combat readiness. Implemented methodological approaches to ensure security of civil and military aviation depend on the achieved level of safety The article points out selected aspects of data analysis in the field of flight safety gathered in IT systems functioning in civil and military aviation supporting the management of flight safety. Selected aspects of data analysis with different tools influencing the safety of flights are presented. The article also points to the role of the inspection functions and supervision at the stage of execution of normative acts on safety and conduct of flights and the implementation of projects to ensure flight safety. The development of projects firstly preventing air accidents is mentioned as an important action to support flight safety. Increasing level of flight safety in civil and military aviation requires searching for methods to support decisions and actions. The main aim is to develop such methods to support decisions which minimize the risk of errors.

A method for reliability assessment of structural components of aircraft and sea-going ships with taking into account a given failure generation model

Abstract This paper presents a metod for reliability assessment of structural components on the basis of diagnostic parameters recorded during operation of aircraft and sea going ships. It was assumed that a potential failure may simultaneously concerns surface wear process and fracture of an arbitrary structural component. In order to develop a reliability assessment model some elements of random walk theory were applied. This work covers surface wear density functions of a component. In the case of surface wear the model is based on a difference equation from which, after transformation, a Fokker-Planck partial differential equation was obtained. By solving the equation component’s surface wear density function is achieved. In the second part of the work a generalization of the model was made by introducing to it probability of disastrous fracture of a component. As a result, a generalized Fokkera-Planck’s equation was obtained. By making use of the equation, was obtained a relationship for assessment of reliability of a structural component in case when failure occurs due to surface wear with taking into account possible fracture of the component. In the end a numerical example which shows practical application of the developed method, is attached.

Structural Health Monitoring of Aero-Engines in Non-stationary Operations

With the ultimate goal of rotating machinery diagnosis using Instantaneous Angular Speed (IAS) and Time of Arrival (TOA) signals, this paper provides the theoretical background of non-stationary processes existing in the aero-engines and their monitoring using atypical encoders (e.g. fans, compressors and turbine blades cooperating with the induction sensors, AC and DC generators). The model of TOA signal including aperiodic, periodic and stochastics components has been described. The classical and expert approach to monitoring of operational and structural health parameters (CM, NDT, SHM) of aircraft and its power transmission system has been also described. Finally, the experience of the Tip Timing method used in the Armed Forces of the Republic of Poland is presented. The possibility of structural health monitoring and active controlling of the material fatigue by the aero-engine user through interference in the fuel system adjustment quality has been confirmed. Phase portraits have been used to analyze TOA components in transient state of the engine. Diagnostic criteria and expert algorithms have been verified during active and passive experiments.

Structural Health Monitoring of Turbomachinery using TOA Signal and Expert Software

The article portrays a holistic approach to fatigue prevention of turbomachines, based on: 1) rotating state observer of e.g. compressor or turbine blades; 2) tip timing method of indirect, contactless vibration measurement of rotating elements; 3) theoretical basics of sensor working; 4) expert analysis of measurement signal taking into consideration the modal characteristics of rotating state observer, spectra of monitored dynamic phenomena and characteristics of measurement chain; 5) a proactive intervention of the user in fatigue processes – by optimization of operation process of a turbomachine on the basis of the results of diagnostic tests, before damage occurs. The discussed subject matter was illustrated with examples of aviation engines, steam turbines, as well as industrial fans. Upon above 20 years of operational experience in the aviation of the Armed Forces of the Republic of Poland were proved both the purposefulness of a complex analysis of time of arrival (TOA) measurement signal and user intervention in fatigue processes arising out of human mistakes occurring during production, repair, operations, staff training and aviation supervision and user intervention on the stage preceding a fatigue cracking. The obtained results confirmed the purposefulness of using data from structural health monitoring (SHM) to interfere in fatigue processes taking place in antropotechnical device under testing (DUT, in the machine and its environment).

Dynamic Properties Modeling of the Thermoelectric Fire Sensors in the Aircraft Fire Suppression System

Abstract The paper presents selected results of work at the Air Force Institute of Technology (AFIT) in the concerning modeling the dynamic properties of fire detectors used in aviation fire protection systems. In order to determine the conditions of false fire signals, the simulation models of thermoelectric fire detectors have been developed. Simulation models were tested in Matlab-Simulink computational packages for various methods of heating and cooling the sensors (among others, changes in ambient air temperature of the sensor, caused by the EWU exhaust gas diffusers were simulated – these diffusers are used to distribute flue gases from helicopter engines).

Jakościowe i ilościowe szacowanie ryzyka na podstawie analizy zdarzeń w lotnictwie wojskowym

Abstract Zarządzanie ryzykiem rozumiane jest jako proces wspierający podejmowanie decyzji poprzez systemową ocenę możliwych sposobów działania, identyfikację zagrożeń i korzyści oraz wskazywanie najlepszego sposobu wykonywania zadań lotniczych. W artykule przedstawiono metodologię jakościowego i ilościowego oszacowania ryzyka w oparciu o analizę zdarzeń lotniczych w lotnictwie wojskowym. Procedura proponowanego podejścia zawiera się w algorytmie szacowania stopnia prawdopodobieństwa i ważności oraz w kolejnych czynnościach: identyfikacji czynnika niebezpieczeństwa (CZN) danej kategorii, analizie ryzyka związanego z danym CZN, wyznaczeniu ryzyka, określeniu czynności korygujących, prognozowaniu ryzyka i jego weryfikacji w następnym okresie oceny. Na uproszczonym schemacie blokowym przedstawiono propozycję realizacji procedury jakościowego i ilościowego szacowania ryzyka z wykorzystaniem funkcjonującego w lotnictwie wojskowym systemu informatycznego TURAWA.

Qualitative and Quantitave Risk Evaluation on the Basis of Military Aviation Event Analysis

Abstract Risk management is understood as a process supporting decision making through systemic assessment of possible courses of action, identification of hazards and benefits, and indication of the best way to carry out aviation tasks. The article presents a method of qualitative and quantitative risk assessment on the basis of military aviation incident analysis. The procedure of the suggested approach is contained in a probability and severity degree estimation algorithm and in subsequent steps: of identifying the risk factor (CZN) of a given category, analysis of risk associated with a given CZN, determination of risk, defining correcting actions, risk forecasting and its verification over the following assessment period. A simplified block diagram presents a proposal of the implementation of a qualitative and quantitative risk estimation procedure with the use of the TURAWA IT system, which function in the air forces.

Management of the training process of military pilots based on the analysis and assessment of flight parameters from on-board recorders

Abstract The main and unchangeable principle of aviation activities is to preserve the conditions for safe flying. In present conditions, in constantly growing tasks, aviation requires organizational and methodological treatments at the highest quality. Article is devoted to the analysis of parametric information accumulated through on-board storage media registration of flight data. The article presents selected examples of methods and tools to analyze data and identify corrective and / or preventive actions, which help to increase the effectiveness and efficiency of the entire process of flight training. Conducted in the article discussion and examples highlight the important role of objective flight control as a tool for continuous monitoring of the level of security of performed air tasks in terms of piloting techniques and technical efficiency of the aircraft.

Research method of dynamic capability of an actuating block of the SSP-FK aircraft fire suppression system in false alarm aspect

Numerous cases of self-activation of the SSP-FK aircraft fire suppression system (including commissioning of valves and extinguishing tanks) testify about the fact that it is not yet fully understood in the technical aspect, and because of the performed role on the aircraft is the basic element to ensure flight safety. Solving problems with false fire signalling of the SSP-FK system is an important issue for the safe operation of aircraft and military helicopters, because it is preventive (to warn the crew of the possibility of fire) and rescue system (aiming at extinguish the fire) in each phase of a flight. In addition, the SSP-FK system is used on many types of military aircraft (including helicopters from W-3/3W/3WA/3PL and Mi/8/14/17/24 family as well as An-28 and Tu-154M aircraft. The paper presents selected results of work in the Air Force Institute of Technology in the study of SSP-FK fire suppression system (as one of the main protection systems on-board) used on many types of military aircraft operated in the Polish Armed Forces. In determining the conditions of the false signalling of fire, simulation models of action blocks implementing of the SSP-FK fire suppression system were developed. The research on simulation models was performed in Matlab-Simulink and Circuit-Maker computing packages. The results of these works were used to diagnose selected modules and blocks of the SSP-FK system during the study of actual cases of their false activation.