• Journal of the military operations research society of Korea
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• v.30 no.2
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• pp.108-121
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• 2004

This paper deals with a procedure of changing the current inspection & replacement periods for ROKAF aircraft parts. ROKAF is mostly operating aircraft of foreign makes, and takes maintenance actions according to Technical Orders(TO.) published by foreign aircraft manufacturers. Therefore ROKAF inspects and replaces specific parts at the time noticed from T.O.. These inspection and replacement periods are determined by manufacturers according to the standard operating environment and parts' durability. But the standard operating environment Is different from operator's environment. Because of this difference, the inspection and replacement periods have to be changed according to operators' operation environment. It is resonable that the manufacturer, having design materials and life test data of parts, changes those periods together with materials of operators' operation environment. But we have many difficulties in obtaining the design materials and life test data. Then this paper proposes a procedure of changing the periods of aircraft's parts with life data obtained during operating aircraft. For the reliability analysis, a software of RELEST (Reliability Estimation Version 1.0) is used.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.26 no.4
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• pp.116-121
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• 2018

According to the incresement of aging aircraft, Republic of Korea Air Force (RoKAF) conducted a teardown inspection of aircraft's EWIS (electrical wiring interconnection system) to determine the status of deterioration and the influence of failure occurrences due to it. The inspected aircraft were the retired fighter jets that had been used for more than 40 years. By analyzing defect type and the defect tendency, RoKAF can establish the necessary measures for the usage extension of their fleet and furthermore, the analysis results can be used as a basic data for the preparation of it's aircraft aging. EWIS inspection was done throughout careful visual inspection technique by removing all the ducts and pipes located in the fuselage and wings. For the aircraft wiring where no damage was found, the elongation tests were performed to determine the deterioration of wiring according to the location of the aircraft. The connectors, which is the main cause of intermittent failure, were completely disassembled and inspected for internal damage such as corrosion, abrasion, and traces of foreign objects. The detected defects were classified into 4 severity levels based on the type of damage, and the classified defects were weighted according to the criticality which may affects to it's system to establish the action plan.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.6
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• pp.525-533
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• 2009

Emphasis in the paper is placed on describing guided wave successes and challenges for applications in aircraft and composite materials inspection. Guided wave imaging methods discussed includes line of sight, tomography, guided wave C-scan, phased array, and ultrasonic vibration methods. Applications outlined encircles lap splice, bonded repair patch, fuselage corrosion, water loaded structures, delamination, and ice detection and de-icing of various structures.

• Journal of the military operations research society of Korea
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• v.33 no.1
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• pp.19-29
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• 2007

This study deals with developing and operating Reliability Analysis & Evaluation System for aircraft parts by analyzing ROKAF's AMMIS and phase inspection data for optimal inspection frequency. We suggest operating model with improving and adjusting inspection cycle by analyzing failure time data and tendency of crack with RELEX and Minitab software.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.172-173
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• 2021

In recent, unmanned Aircraft Systems (UAS) have been widely used for various purposes, such as safety inspection, facility condition inspection, progress monitoring, in the architecture engineering, and construction (AEC) industry. This technology can provide visual assets regarding the conditions of construction jobsites as well as constructed facilities during flying over the point of interests. With the significant interests in this advancement, the recent studies have presented how the UAS can be applied fro different types of facilities (e.g., buildings, power genereation systems, roads, or bridges) to inspect the current conditions of them for safe operations as well as public's safety. This study reviewed the receent studies to document their scientific findings and practical contributions, as well as provided the overview of further implications for future studies.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.5
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• pp.631-638
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• 2013

The probabilistic fatigue life analysis is one of the common methods to account the uncertainty of parameters on the structural failure. Frequently, the Bayesian approach has been demonstrated as a proper method to show the uncertainty of parameters. In this work, the application of probabilistic fatigue life prediction method for the aircraft structure was studied. This effort was conducted by using the PoF(Probability of Failure) based on Bayesian approach. Furthermore, numerical example was carried out to confirm the validation of the suggested approach. In conclusion, it was shown that the Bayesian approach can calculate the probabilistic fatigue lives and the quantitative value of PoF effectively for the aircraft structural component. Moreover the calculated probabilistic fatigue lives can be utilized to determine the optimized inspection period of aircraft structures.

• Journal of the Korea Institute of Military Science and Technology
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• v.2 no.2
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• pp.83-91
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• 1999

Dynamic characteristic of manufacturing stage is understood and the utilization of each machine is maximized by developing on-line dynamic CAPP system to consider the overloads in the aircraft part manufacturing line. In this paper, a scheme of production planning and scheduling system was proposed through inspection about some predeveloped CAPP system. Developed production planning and scheduling system included process planning module. After precise inspection of some FMS line schema at domestic heavy industry, optimized FMS line was applied to aircraft part manufacturing and repairing factory. By virtue of considering overloads of factory and machine through on-line dynamic CAPP system, the utilization of resources is maximized and manufacturing lead time is minimized.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.4
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• pp.1-8
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• 2020

Mechanical components that support structures in aerospace and power generation industries require high-strength materials. Particularly, in the aerospace industry, aluminum alloys, titanium alloys, and composite materials are increasingly used due to their high maneuverability and durability to withstand low temperature extreme environments; however, ultra-high-strength steel is still used in key components under heavy loads such as landing gears. In this paper, the fault cause analysis and troubleshooting of aircraft parts made of ultra-high-strength steel (300M) broken during normal operation are described. To identify the cause of the defect, a temporary inspection of the same aircraft was performed, and material testing, non-destructive inspection, microstructure examination, and fracture area inspection of the damaged parts were performed. Fracture analysis results showed that a crack in the shape of a branch developed from the tool mark in the direction of the intergranular strain. Based on the results, the cause of fracture was confirmed to be stress corrosion.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.11
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• pp.87-93
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• 2020

A key component of aviation safety is to eliminate the errors in commercial aircraft air data systems to ensure stable aviation operation. Although the technical aspects such as the maintenance and inspection play a pertinent role, human errors are expected to have a similar or even larger influence on the aviation safety. Aviation maintenance and inspection tasks are often performed by a complex organization, in which individuals perform a variety of tasks in an environment involving time pressure, sparse feedback, and complex conditions. These situational characteristics, combined with the general tendency of human error, may lead to various types of errors, which may have critical consequences such as accidents and loss of life. For instance, if an amber message "IAS DISAGREE" is displayed on the primary flight display while the aircraft is rolling on the runway to takeoff, the crew immediately performs a rejected takeoff operation and troubleshoots the air data system. This paper proposes alternative approaches to address the occurrence of defects due to the human factors involved in the practical processes of the air data system of commercial aircraft.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.5
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• pp.805-811
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• 2011

Aircraft MLG and wing structures have been recognized as fatigue critical structures and exposed to the risk of fatigue crack initiation and propagation. Furthermore, these structures are frequently subjected to serious dynamic loading condition during a Hard Landing which may lead to their failure. Especially, structural integrity of MLG and wing components is decreased as the flight time increased because of the fatigue damage accumulated on the aircraft. In this study, the effects of Hard Landing on the MLG and wing components of aging aircraft were evaluated by using numerical approach. To achieve the aim, a finite element model has been developed and simulations were conducted by varying the landing conditions. As a result, it was revealed that the high stress concentration phenomenon was occurred at the lower Side Brace of MLG. Thereby, the intensified inspection for the lower Side Brace should be considered to prevent unexpected aircraft mishap.