• International Journal of Aeronautical and Space Sciences
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• v.16 no.3
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• pp.451-462
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• 2015

Safety is the first priority in civil aviation, and so the International Civil Aviation Organization (ICAO) has introduced and mandated the use of Safety Management Systems (SMS) by airlines, airports, air traffic services, aircraft maintenance organizations, and training organizations. The aircraft manufacturing industry is the last for which ICAO has mandated the implementation of SMS. Since SMS is a somewhat newer approach for most manufacturers in the aviation industry, they hardly believe in the value of implementing SMS. The management of safety risk characteristics that occur during early aircraft development stages and the systematic linkage that the safety risk has to do with an aircraft in service could have a significant influence on the safe operation and life cycle of the aircraft. This paper conducts a case analysis of the McDonnell Douglas MD-11 accident/incident to identify the root causes and safety risk levels, and also verified why aircraft manufacturing industry should begin to adopt SMS in order to prevent aircraft accident.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.4
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• pp.161-167
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• 2020

In the process of cutting large aircraft parts, the tool may be abnormally worn or damaged due to various factors such as mechanical vibration, disturbances such as chips, and physical properties of the workpiece, which may result in deterioration of the surface quality of the workpiece. Because workpieces used for large aircrafts parts are expensive and require strict processing quality, a maintenance plan is required to minimize the deterioration of the workpiece quality that can be caused by unexpected abnormalities of the tool and take maintenance measures at an earlier stage that does not adversely affect the machining. In this paper, we propose a method to indirectly monitor the tool condition that can affect the machining quality of large aircraft parts through real-time monitoring of the current signal applied to the spindle motor during machining by comparing whether the monitored current shows an abnormal pattern during actual machining by using this as a reference pattern. First, 30 types of tools are used for machining large aircraft parts, and three tools with relatively frequent breakages among these tools were selected as monitoring targets by reflecting the opinions of processing experts in the field. Second, when creating the CNC machining program, the M code, which is a CNC auxiliary function, is inserted at the starting and ending positions of the tool to be monitored using the editing tool, so that monitoring start and end times can be notified. Third, the monitoring program was run with the M code signal notified from the CNC controller by using the DAQ (Data Acquisition) device, and the machine learning algorithms for detecting abnormality of the current signal received in real time could be used to determine whether there was an abnormality. Fourth, through the implementation of the prototype system, the feasibility of the method proposed in this paper was shown and verified through an actual example.

• Journal of Aerospace System Engineering
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• v.17 no.6
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• pp.27-34
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• 2023

This paper presents the application of a magnetic gear to the electric propulsion system for an aircraft. Since high torque is required in aircraft electric propulsion systems, combining a speed reducer can amplify the torque. However, mechanical gears have issues, such as friction, vibration, and heat generation, which lead to maintenance challenges. In the case of a direct-drive motor that does not use mechanical gears, the size and weight of the motor increase to achieve high torque. This paper proposes the application of a magnetic gear to solve the maintenance issues of mechanical gears and the weight increase problem of direct-drive motors in aircraft electric propulsion systems. In this paper, a magnetic gear suitable for aircraft electric propulsion systems is designed, and it is compared with a direct-drive motor in terms of performance and the feasibility of applying the magnetic gear is verified.

• Journal of Advanced Navigation Technology
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• v.24 no.3
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• pp.205-211
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• 2020

Wiring defect is a major concern for safe aircraft operations. However, troubleshooting process of a wiring defect is very difficult due to extensive and complex wiring system and installed location. Recently, time domain reflectometer (TDR) equipment that enables effective defected wiring troubleshooting has been introduced. Unfortunately, TDRs have not practically adopted by most of airlines' maintenance departments because the effectiveness and usefulness of TDRs have not been verified. This study was conducted to verify if TDRs can identify the location and type of defected aircraft wiring, and whether they can be applied for troubleshooting purposes. Experimental plan was established by using various wires and connections applied to actual aircraft and the observed results were compared with the TDR operation guide. The usability of the TDR in actual aircraft wiring defect detection may be acceptable as the experimental results showed similar results to the TDR operation guide.

• Journal of Aerospace System Engineering
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• v.17 no.4
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• pp.95-103
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• 2023

Aircraft engine parts repair is a field belonging to the lowest level in the hierarchy of the aircraft industry, and it is marginalized in terms of research, compared to aircraft manufacturing or maintenance that belong to the upper level. On the other hand, in 2019, Korean Air's Powerplant Maintenance Center paid USD $130 million to foreign countries for engine parts repair, making it an industry with great need for localization. To achieve the goal of localizing engine parts repair, a certification system is needed that can perform independent repairs based on the development of repair technology, aligning contractual relationships with engine manufacturers, and free from dependence on engine manufacturers or foreign repair companies. The purpose of this study is to provide a basis for subsequent research to secure an actual certification system by suggesting the need for securing such a certification system.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.11
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• pp.127-133
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• 2003

Pin-on-disk and hardness tests using mechanical components of M-20J aircraft braking system were performed to identify the friction and wear characteristics. The intention of this work was also to analyze a 5-year term maintenance record of an M-20J aircraft. used for flight training at Hankook Aviation University, and to determine the reliability of the brake system of an M-20J aircraft. The mean wear coefficients of the lining sliding against the brake disk were compared between the test and reliability estimation to obtain a predictive wear model.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.22 no.2
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• pp.34-39
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• 2014

Airworthiness authorities specify the technical standards of airworthiness that propose minimum requirement of the commercial transport category and apply the rules in the certification process to ensure the safety of the aircraft. The Federal Aviation Administration and other national airworthiness authorities define the fatal accident risk levels for the safety assessment of the aircraft system and establish standard procedures to apply both qualitative and quantitative analysis techniques. However, an accident or incident may occur by the combination of various factors, although the aircraft is designed in accordance with the strict standards and approval by the Airworthiness Authorities. There are some key factors, such as human error, unpredictable complex system failures, degradation of the components reliability, improper maintenance task and intervals. Risk can be reduced by reflecting aircraft operational experience with similar types of aircraft in the process of aircraft development and safety assessment. Result of the root cause analysis for the Airbus A300-600 incident in which the aircraft engine reverser was deployed in the air have been introduced to reflect the design of system and related components. Also, this paper suggests to create a big-database in order to provide a feed-back to the FAR Part 25 transport category design and safety assessment of the operational experience.

• Journal of the Korean Society for Nondestructive Testing
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• v.13 no.2
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• pp.81-93
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• 1993

• Journal of Advanced Navigation Technology
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• v.20 no.5
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• pp.446-452
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• 2016

The aircraft has to be considered for safety very importantly because of peculiarity of flight in the air, so it should be retained through proper inspection and maintenance not only in production phase but also in operating phase. Recently, it is using the latest technology as engineering approach not depending on human factor to determine on maintenance needs, and domestic production rotary aircraft also has the health & usage monitoring system to measure and to monitor major components. However, continued vibration exceedance phenomenon occurred in production and operation phase because of inappropriate thresholds, and it confirmed as false alarm which is not necessary to repair. In this paper, it is described that operational concept of HUMS, and especially it contains a study result for efficiency of aircraft operation and ultimately the improvement of flight safety by optimizing HUMS thresholds to determine efficiently necessity of maintenance under limited conditions and by establishing inspection/maintenance procedures when the re-designated thresholds exceedance occurred.

• The Journal of Information Systems
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• v.8 no.2
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• pp.145-168
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• 1999

There are still occurring aviation accidents in spite of great preventing efforts all over the world. This paper contains some methods to prevent aircrafts deficiencies and accidents. First part of this paper refers to the background of those aviation deficiencies on mechanical, human and environment structures which influence directly to the air accidents and general survey on various theories of the aircraft's systems. On the way we discussed the general situations of the air tool's deficiencies which cause tragic accidents to the human lives and assets. After analysis on the situations we suggest the new systems which would forecast more detail accuracies concerned air elements for the safety flying. Then we introduce the following new systems resulting from the forecasting which can solve problems on aircraft deficiencies and complex interrelationships among air accidental factors. To simplify the complex systems, we needed to build the mechanical and organizational database for maintaining the procedures of the past troubleshooting on the major parts preventing deficiencies of those mechanical units. These suggested systems will contribute a great deal of aids, the maintenance credibility and air safety for the air operations and all customers in the world. Avoiding the past troubleshooting from just by using simple systems which can forecast main causes of the units and parts of the crafts, this system will be able to provide excellent management tools for the promoting aviational industries. The comfortable and convenient air operations are very valuable works, and the scientific method and detail maintenance will improve our daily air life by minimizing accidents. Adapting these developing systems, for the forecasting aircraft deficiencies and accidents can be integrated with the other aircraft management systems to promote more air safety in the world. This study is focused to eliminating aircraft accidents through forecasting deficiency symptom procedures by relational coordinations among all of the systems. Futhermore we need continuously detailed analysis and study for eliminating air accidents all together those who work in those fields.