• Journal of Aerospace System Engineering
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• v.14 no.spc
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• pp.1-6
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• 2020

The flaw tolerance evaluation requirement prescribed in Federal Aviation Regulation (FAR) §29.571 Amendment 55 was established in 2012. As a result, there are not many datas of flaw tolerance evaluation. This paper introduces the series of processes and evaluation methods carried out for certification based on the flaw tolerance evaluation. An initial flaws were artificially formed on the main rotor actuator and then the damage tolerance test was performed, which was twice life time of design requirements, to demonstrate that the main rotor actuator of the rotorcraft is sufficiently capable of flaw tolerance.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.1
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• pp.55-62
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• 2020

It is necessary to develop digital flight control system by digital control technology to ensure stability and maneuverability of rotary helicopter. It is important to meet functional requirements of helicopter flight control system OFP and verify system reliability directly linked to flight safety as a core technology that avoids the transfer of technology by overseas advanced helicopter manufacturer. In this paper, we studied how to perform FMET for operational flight program of rotary automatic flight control system.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.2
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• pp.105-114
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• 2008

In this study, the sizing and performance analysis program is developed for the canard rotor wing(CRW) aircraft which operates in dual modes (fixed wing mode and rotary wing mode). The developed program is verified for both fixed wing and rotary wing modes using the existing aircraft data and the design optimization formulation is made to perform the reconnaissance mission. For the canard rotor wing aircraft optimization , multi-objective function is constructed to consider both the fixed wing mode and rotary wing mode the weighting factor. For six design cases with different weighting factors and different design constraints, the optimization is performed and improved rotor design results are derived.

• Journal of the Korean Society of Propulsion Engineers
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• v.7 no.3
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• pp.38-44
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• 2003

In this study, a performance model of the smart UAV propulsion system with ducts, tip jets and variable main nozzle, which has flight capability of the rotary wing mode for the take-off/landing and low speed forward flight as well as the fixed wing mode for high speed forward flight, has been newly developed With the proposed model, steady-state performance analysis was performed at various flight modes such as rotary wing mode, fixed wing mode, compound ing mode and altitude as well as at flight speed conditions. In investigation of performance analysis. it was noted that the operational capability of the propulsion system was limited due to the duct losses depending on each flight mode, and the limitation with the altitude variation case had much greater than that with the flight speed variation case.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.05a
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• pp.177-182
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• 2003

In this study, a performance model of the Smart UAV propulsion system with ducts, tip jets and variable main nozzle, which has flight capability of the rotary wing mode for the take-off/landing and low speed forward flight as welt as the fixed wing mode for high speed forward flight, has been newly developed. With the proposed model, steady-state performance analysis was performed at various flight modes and conditions, such as rotary wing mode, fixed wing mode, compound wing, mode altitude and flight speed. In investigation of performance analysis, it was noted that the operational capability of the propulsion system was limited due to the duct losses depending on each flight mode, and the limitation with the altitude variation case has much greater than that with the flight speed variation case.

• Information and Communications Magazine
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• v.33 no.2
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• pp.86-92
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• 2016

본고에서는 최근 각광받고 있는 드론관련 기술 중 비행에 필수적인 비행제어 기술 및 이를 위한 드론 상태추정 기술의 기초에 대해 소개한다. 고정익, 회전익 등 다양한 드론 중 본고에서는 다양한 활용 가능성으로 인해 현재 민간 및 상업용으로 가장 널리 쓰이고 연구되고 있는 멀티로터 타입의 드론에 대해 서술한다. 비행제어를 위한 드론의 동역학에 따른 기초적인 비행제어 방법소개, 비행제어가 가능토록 드론에 탑재되는 일반적인 센서 종류와 이를 활용한 위치, 회전 추정 방법들에 대해 소개하며 현재 관련 기술 현황에 대해 소개한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.736-741
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• 2017

This paper examines the design for improving the wiper system of rotorcraft. During rotorcraft operation, the wiping performance and excessive clearance can decrease. The wiper system consists of a wiper arm assembly, motor, convertor and flex drive. If there is a problem with the wiper system, the operation ability decreases because the operation is restricted in a rainy environment. There are two main causes of the problem of the wiper system: the lifting forces acting on the wiper arm in aircraft flight and the excessive gap of the components. To remedy these two problems, the wiper arm was improved. The improvements included increased contact pressure on the wiper arm (spring tension), improved gear clearance, and material and shape changes. Durability test, aircraft ground test and flight test were carried out to verify the improved shape, and it was confirmed that the wiping performance and clearance problems were solved. Currently, the rotorcraft is operated without problem by applying the improved shape, and this design improvement process will be a useful reference for future rotorcraft development.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.134-141
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• 2019

This paper is a study on design improvement of rotorcraft horizontal stabilizer. The rotorcraft horizontal stabilizer stabilizes the behavior of the pitch, yaw, etc. from the aircraft. Because of this role, horizontal stabilizers are a major component (Flight Safety Part) that affects flight safety on rotorcraft. However, when the rotorcraft was operated in domestic, cracks were found in the inner structure of the horizontal stabilizer and design improvement was needed. In this paper, we identified the two causes of the horizontal stabilizer crack defects through fracture analysis and structural analysis. The first is the tightening torque when the bolt is tightened, and the second is the lead-lag behavior of aircraft. In order to improve these two causes, bolt fastening method, flange structure and thickness were changed and composite ring was applied. In order to verify the design improvement, the structural analysis was performed and the structural strength was improved. Also Fatigue analysis of the internal structure (Rib 1) was performed and it was confirmed that the requirements were satisfied.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.5
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• pp.490-498
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• 2010

This paper presents an autonomous target tracking approach and technique for transmitting ground control station image periodically for an unmanned aerial vehicle using onboard gimbaled(pan-tilt) camera system. The miniature rotary UAV which was used in this study has a small, high-performance camera, improved target acquisition technique, and autonomous target tracking algorithm. Also in order to stabilize real-time image sequences, image stabilization algorithm was adopted. Finally the target tracking performance was verified through a real flight test.

• 한국항공운항학회:학술대회논문집
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• 2016.05a
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• pp.301-305
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• 2016

국내 조종사 자격증명(회전익항공기)은 육상 단발/다발, 수상 단발/다발로 등급이 분류되어 있어 육상 다발 자격증명을 이미 취득한 조종사가 육상단발 헬리콥터 비행을 하기 위해서는 육상 단발 자격증명을 추가로 취득해야 하는 것이 국내 자격증명 제도이다. 이에 본 논문에서는 비행기와는 다른 독특한 헬리콥터 비행특성에 대해 살펴보고 헬리콥터 등급분류인 단발/다발 구분의 필요성에 대해 검토하였다. 또한, 세계 및 국내 민수 헬리콥터 산업의 발전방향과 해외 항공선진국 조종사 자격증명 제도를 비교하여 국내에 적합한 회전익항공기 조종사 자격증명 등급분류에 대한 개선방안을 도출하고자 한다.