• Journal of the Korean Society for Aviation and Aeronautics
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• v.31 no.4
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• pp.28-44
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• 2023

This study investigates aircraft lessor business models by studying cases and interviewing experts to analyze investors and business strategies of aircraft lessor. The results confirm that there is a wide range of investors including institutional investors, financial institutions, insurance companies, corporations, and wealthy individuals for aircraft lessor. Aircraft lessors can be categorized based on its required rate of return (cost of capital) into bank-investing core, institutional investor-investing value-added, and hedge fund-investing opportunistic. Aircraft lessor decides leasing rate by aircraft purchasing price and lessee's credit rating. Core aircraft lessors invest in new aircrafts for new placement or sale-and-leaseback strategy requiring little technical risk in aircraft, value-added lessors invest in middle-aged aircrafts for re-leasing, opportunistic lessors invest in old aircrafts for freighter conversion or part-out strategy requiring high level of expertise. This study provides insights for future Korean aircraft lessor establishment and investment.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.24 no.2
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• pp.19-24
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• 2016

Positional stability analysis based on aerodynamic forces and induced moments of formation flight using two small aircraft models is presented. The aerodynamic force and moments of the trailing aircraft are analyzed in the aspect of flight stability. The induced moments with the change of local flow direction by wing-tip vortex from the leading aircraft can affect the flight positional stability of aircraft in closed formation flight. Aerodynamic forces and moments of trailing aircraft model are measured by 6-component internal balance at the 49 locations with vertical and lateral space between two aircraft models. Results are shown that the positional stability of trailing aircraft in formation flight can be analyzed by positional stability derivatives with vertical and lateral space. It is concluded that flying positions can be important factors for aircraft position stability due to induced aerodynamic force and moments with vertical and lateral spacing by the variation of flow pattern from the leading aircraft in formation flight.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.1
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• pp.77-83
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• 2010

In this paper, we proposed new outworn aircraft management procedure. ROKAF has both good management skill and information system, AMMIS, regarding aircraft maintenance based on all kinds of aircraft's defects. To optimize and secure aircraft's operation, management of the outworn aircraft is very important for ROKAF. With respect to these outworn aircraft's defects and maintenance, we analyzed defects occurrence pattern of outworn aircraft by using AMMIS data and Market Basket Analysis, and found the specified association rules for each defect. By using these association rules, we developed new management procedure for outworn aircraft based on the results of affinity analysis. The management procedure in this paper will also be used to optimal operation and maintenance of other aircraft and weapon systems.

• Advances in aircraft and spacecraft science
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• v.9 no.4
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• pp.335-347
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• 2022

Airport operations are well-known as a bottleneck in the air traffic system, putting growing pressure on the world's busiest airports to schedule arrivals and departures as efficiently as possible. Effective planning and control are essential for increasing airport efficiency and reducing aircraft delays. Many algorithms for controlling the arrival/departure queuing area are handled, considering it as first in first out queues, where any available aircraft can take off regardless of its relative sequence with other aircraft. In the suggested system, this problem was compared to the problem of scheduling n tasks (plane takeoffs and landings) on a multiple machine (runways). The proposed technique decreases delays (via efficient runway allocation or allowing aircraft to be expedited to reach a scheduled time) to enhance runway capacity and decrease delays. The aircraft scheduling problem entails arranging aircraft on available runways and scheduling their landings and departures while considering any operational constraints. The topic of this work is the scheduling of aircraft landings and takeoffs on multiple runways. Each aircraft's takeoff and landing schedules have time windows, as well as minimum separation intervals between landings and takeoffs. We present and evaluate a variety of comprehensive concepts and solutions for scheduling aircraft arrival and departure times, intending to reduce delays relative to scheduled times. When compared to First Come First Serve scheduling algorithm, the suggested strategy is usually successful in reducing the average waiting time and average tardiness while optimizing runway use.

• Journal of the Korean Society of Systems Engineering
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• v.11 no.1
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• pp.73-79
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• 2015

This paper describes boundary analysis for modeling Aircraft Carrier Sortie Generation System(CVSGS). An aircraft carrier, as a super system, is a warship going into battle by operating a number of aircraft on deck and it should be lay down a definition about aviation operations interacting between aircraft carrier and carrier air wing in small deck area. For this reason this paper models common aviation support system for generating sortie basic unit of carrier aviation operations unlike to general warship and defines boundaries between this system and aircraft carrier and carrier air wing. This paper analysis activities of aircraft carrier and embarked carrier air wing in carrier aviation operations, and analysis and defines boundaries Aircraft Carrier Sortie Generation System(CVSGS) to perform core functions in interacting between aircraft carrier and embarked carrier air wing.

• Journal of Aerospace System Engineering
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• v.14 no.6
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• pp.36-43
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• 2020

The purpose of this study is to present the internationalization of South Korea's aircraft maintenance certificate for mutual recognition of aircraft maintenance license qualifications among various countries in preparation for an internationalization of the work conducted by the aviation industry. To achieve this objective, this study reviews the aircraft maintenance license training system and compares the standards for aircraft maintenance certification established by the Convention on International Civil Aviation with the standards for issuing domestic aircraft maintenance licenses. This comparative analysis shows that the domestic curriculum of aircraft maintenance licenses differs from international standards. As a result of this study, an improvement plan of the education content was proposed to enable the licensing qualifications of domestic aircraft maintenance licenses to be mutually recognized among different countries.

• Advances in aircraft and spacecraft science
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• v.8 no.4
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• pp.331-344
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• 2021

Airframe internal and external specifications are the product of intensive intellectual efforts and technological breakthroughs distinguishing each aircraft manufacturer. Therefore, geometrical information characterizing aircraft primary aerodynamic surfaces remain classified. When attempting to model real aircraft, many members of the aeronautical community depend on their personal expertise and generic design principles to bypass the confidentiality obstacles and sketch real aircraft airfoils, which therefore vary for the same aircraft due to the different designers' initial assumptions. This paper presents a photogrammetric shape prediction method for deriving geometrical properties of real aircraft airframe by utilizing their publicly accessible static and dynamic visual content. The method is based on extracting the visually distinguishable curves at the fairing regions between aerodynamic surfaces and fuselage. Two case studies on B-29 and B-737 are presented showing how to approximate the sectional coordinates of their wing inboard airfoils and proving the good agreement between the geometrical and aerodynamic properties of the replicated airfoils to their original versions. Therefore, the paper provides a systematic reverse engineering approach that will enhance aircraft conceptual design and flight performance optimization studies.

• Journal of the Korean Society of Systems Engineering
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• v.5 no.2
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• pp.49-56
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• 2009

KC-100(KAI Civil Aircraft, Small Series) aircraft is 4 seats general aviation aircraft with single piston engine which is developing under FAA part 23 category by Korea Aerospace Industries(KAI) and will be a shadow program for civil aircraft safety infrastructure improvement. This aircraft will be the first civil aircraft developed in Korea meeting the Korean regulatory KAS Part 23 requirements. Type certification for KC-100 aircraft was applied at the second half of this year. The type certificate is expected to be issued after 3 years of design, prototype manufacturing, ground and flight tests. In this paper the system engineering process for civil aircraft was first reviewed. Next, the differences and similarities in the system development between military and civil aircraft were systematically examined using experiences for KAI military aircraft development program.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.5 s.110
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• pp.503-513
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• 2006

The duration time of aircraft noise event is also an important factor for the evaluation of civil aircraft noise, which is considered as a notable characteristic of military aircraft noise. SEL is proved as a suitable noise metric for the measuring military aircraft noise of various flight pattern considering the duration time of noise event. This study reviews whether SEL is a suitable for measuring civil aircraft noise and study shows SEL is fairly compensating the duration time of civil aircraft noise event for the evaluation of aircraft noise. Noise metric for the evaluation aircraft noise based on SEL is more appropriate than based on $L_{MAX}$ for compensating duration time of noise event either military aircraft or civil aircraft. In this reason, current formula of WECPNL based on energy average of measured $L_{MAX}$ for the evaluation of aircraft noise impact in 'Test Method of Noise and Vibration of Korea' is recommended to be amended to formula of WECPNL based on energy average of measured SEL considering compensation of noise event duration time, if WECPNL is not based on measured EPNL, a metric compensating duration time.

• Journal of the Korea Institute of Military Science and Technology
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• v.25 no.3
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• pp.311-320
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• 2022

In this paper, we studied the optimal method of improving performance for aircraft having various variants within the same type. The study defined configuration of an entire fleet of aircraft being subject to a performance improvement program. And selected the most complicated aircraft configuration among them as a Standard Aircraft for modification by according to the proposed Aircraft Selection Process for developing an optimal Aircraft Performance Improvement Process. Based on the selected the Standard Aircraft, drew a system integration design result and carried out Evaluation Test and obtained Airworthiness Certification. Created the database with the design data of the Standard Aircraft, Evaluation Test, and Airworthiness Certification results, and applied it to variants of aircraft to complete the performance improvement program with optimized schedules and costs. By applying the proposed method to IFF performance improvement program, drew optimal system integration design and completed the program with minimized schedule.