• Journal of Aerospace System Engineering
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• v.12 no.3
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• pp.38-44
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• 2018

Military aircraft may have fatigue cracks in structurally weak areas due to multiple factors such as the accumulation of flight time while perform various missions and unpredictable air conditions. As a fatigue crack progresses, there is a risk that the structure will be destroyed in extreme cases, which can have a significant impact on flight safety. In this study, a cracking phenomenon was observed during the periodic inspection the inner support of the fairing, which is installed to protect the connection between the wing and the body of the aircraft. Therefore, a study on a series of quality improvement processes for reformation was described. In order to identify the causes of cracks, pre-load generation occurrence during the wing assembly process was investigated and a fracture analysis was performed. Also, the design of the support structure was suggested in terms of preventing recurrence of cracks. The structural integrity was verified using a stress and fatigue life analysis.

• Aerospace Industry
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• s.108
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• pp.66-67
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• 2010

수직이착륙, 영어로는 VTOL(Vertical Take-Off and Landing)이라 불리는 기술은 공기역학을 거부한 첨단 항공우주기술이다. 일반적으로 고정익 항공기는 날개에서 발생하는 양력으로 하늘을 날지만 VTOL 항공기는 순수한 엔진 추력만으로 수직으로 이착륙하거나 단거리에서 이륙할 수 있다. 다만 높은 기술적 완성도를 요구하는 만큼 현재까지 실전 배치된 군용기 중 이 기술이 적용된 군용기는 해리어(Harrier)와 V-22 오스프리(Osprey), Yak-38 정도가 고작이다. 수직이착륙 기술에 대해 소개한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.164-172
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• 2020

The fuel oil/heat exchanger installed in military aircraft is a device that cools the lubricant oil supplied to other devices, such as an AMAD, and a hydraulic pump using the low temperature of the fuel is cracked at the AMAD lubricant inlet port. If a crack in the heat exchanger occurs, the lubricant oil supplied to other equipment is not cooled. Therefore, the flight can no longer be performed. In this study, non-destructive inspection and microscopic examination of the fracture surface of the oil port were performed to analyze the crack tendency. The oil pipe connected to the oil port is a titanium pipe, which is fastened with over torque and has been identified as the leading cause of heat exchanger oil port cracks. In addition, it was verified as the main reason for cracking by finite element analysis. The material and diameter of the pipe were changed to improve this defect, and the applied torque was adjusted. In addition, the bending value of the pipe was adjusted to minimize the fatigue accumulation due to pulsating pressure. As a result, no cracks occurred on the heat exchanger via the ground test after the installation of an improved pipe under the same conditions.

• The Journal of Aerospace Industry
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• s.67
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• pp.71-94
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• 2004

전 세계 항공 산업의 비약적인 발전과 더불어 최근에는 군사용 및 항공수송을 위해 주간뿐만 아니라 야간에도 많은 비행이 요구되고 있으며, 이에 따라 항공기 안전운행의 필요성이 크게 대두되고 있다. 이러한 항공기의 안전운행에는 다양한 기술적인 발전이 진행되어 왔고, 야간시각시스템(NVIS)의 발전 역시 항공기 조종사에게 주간과 유사한 시각적 영상정보를 제공함으로써 심리적인 불안감을 해소시키고, 운항정보에 대한 신뢰성과 적시성을 증대시키며, 야간에 항공기를 안전하게 운항하기 위해 조종사의 업무부아(work load)를 줄이기 위한 노력으로 큰 관심사가 되어왔다. 또한 이러한 NVIS를 활용한 기술은 현재 군용항공기 뿐만이 아니라. 민간용 항공기, 자동차, 카메라, 레저용 등으로 그 범위가 확대되어 보급되고 있으며, 활용도 또한 커지고 있고, 수년 전부터 국내에도 이러한 기술이 적용되어 왔기에 이러한 항공기용 야간시각시스템(NVIS)에 대한 전반적인 내용을 소개하고, 향후 국내에서 개발/적용되는 항공기의 NVIS 기술에 대한 기본적인 평가방향을 제시하고자 한다.

• The Korean Journal of Air & Space Law and Policy
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• v.19 no.1
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• pp.79-107
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• 2004

Shielding theory is to allow the construction of a structure that would be shielded by existing permanent structures even thought such structure extends above the height limits prescribed for such zones. This theory is mentioned as recommended practices in ICAO Annex, and is adopted, with modification, in the current Military Airbase Law, amended in August 26th 2002. However, the Military Airbase Law adopts shielding standard allowing 45 meters uniformly, which is a unique standard compared to other countries shielding guideline. The basic principle in applying the shielding theory is, after considering the circumstances of location of shielded structure, whether such structure has physical effect on aeronautical operations. Based upon the basic principle of shielding theory, the uniform application of shielding standard in the Military Airbase Law would undermine the safety of aeronautical operations. This article is to review subsection 2 of section 8 of the Military Airbase Law, which adopts modified shielding theory, and is to suggest better guideline. From a comparative analysis perspective, shielding guidelines of ICAO and other countries will be discussed. Based upon this discussion, the general problems of shielding theory and the specific problems in the Military Airbase Law will be examined. Finally, this article suggests the case-by-case application of shielding theory, considering circumstances of location, for the purpose of ensuring aviation safety.

• Current Industrial and Technological Trends in Aerospace
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• v.4 no.1
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• pp.3-12
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• 2006

세계 항공기산업은 새로운 기술과 새로운 전략, 이른바 ‘차세대’라는 단어로 대변될 수 있는 다음세대를 위한 개발과 전략의 변화를 겪고 있다. 먼저 군용기의 경우 미국의 F-35가 첫 선을 보이면서 차세대 전투기의 새장을 열어가고 있으며 우리나라 역시 T-50/A-50, 한국형헬리콥터(KHP)개발, 조기경보기 도입 등 공군력 강화를 위한 준비들이 단계적으로 이루어지고 있어 그에 따른 산업발전이 기대되고 있다. 민간 항공기를 살펴보면 A-380과 같은 대형 항공기 개발 추세와 A320과 B737과 같은 Narrow-body 항공기 생산이 증가하는 양상을 보이고 있다. 또한 개인용 소형제트기(VLJ)와 같은 항공기들은 차세대 틈새시장(niche market)을 형성, 발전가능성을 열어가고 있다. 민간항공기의 향후 생산전망을 살펴보면, 대형여객기의 경우 2015년까지 총 7,900여대로 연평균 800여대의 생산이 이루질 전망이며 헬리콥터의 경우 연평균 1,870여대로 총 18,730여대의 헬리콥터가 생산될 전망으로 약 1,200억불의 시장을 형성할 것으로 전망되고 있다. 이렇듯 군용기 시장에서는 차세대의 첨단 항공기 개발과 양산이 가시화되고 있으며 민간항공기의 경우, 특정 세분시장(market segment)의 주도적 개발과 양산보다는 비즈니스 환경의 변화와 고객층의 다양화로 인해 각 시장의 고객 니즈(needs)에 부합되는 다양한 항공기 개발과 양산이 이루어질 것으로 보인다.

• Journal of Aerospace System Engineering
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• v.1 no.2
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• pp.1-5
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• 2007

This is a study on the effective and efficient way of airworthiness certification for Korean indigenously developed military aircrafts. Investigating the policy, process, and capability for military aircraft airworthiness certification in USA end Europe, the approach for Korean military aircraft airworthiness certification is recommended. Using FAR as basis for military airworthiness criteria is much more beneficial in initial stage of establishing airworthiness certification system. And all the available resources regardless of civil or military institutes need to be cooperated to accomplish required level of indigenous airworthiness certification capability.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.10a
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• pp.433-435
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• 2016

기술의 발전에 따라 첨단무기체계인 군용항공기는 전투임무 수행시 내장형소프트웨어(Embedded Software)를 통해 기체내의 항공전자 장치, 항법장치, 조종장치 등의 물리적 기계적 움직임을 제어하고 있으며, 내장형 소프트웨어의 비율은 점점 증가하고 있다. 기체의 물리적 기계적 움직임이 내장형 소프트웨어에 의해 제어 되기 때문에 군용항공기의 전투능력 보존과 국방 목적의 수행을 위해선 먼저 내장형 소프트웨어 고유의 특성을 만족하고, 나아가 소프트웨어 안전성, 신뢰성, 보안성을 확보하는 것이 필요하다. 본 논문에서는 설계 단계에서 스케줄성에 대해 정형검증 하여, 내장형 소프트웨어의 실시간성, 결정성, 생존성을 보증하고, 이러한 과정을 통해 전체적인 소프트웨어 안전성, 신뢰성, 보안성을 향상시키는 방안을 연구하며, 추가로 2011년 발표된 항공 소프트웨어 표준인 DO-178C에서 요구하는 정형검증을 적용한 국내 감항인증 표준 제정의 확대방안을 연구한다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.425-429
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• 2007

The noise problem has been a public interest for several years in Korea. Especially, the noises which were emitted from aircrafts on the airport and in the air have injurious effects on people over a vast range. Hence, there need vast data on the aircraft noise to evaluate the effect of various parameters. In present study, the works which consist of social surveys and noise measurements were conducted at points near the airport and the airbase. Total of 1,784 participants give effective responses in forty-five areas nearby the measurement points. Questionnaires asked the responses concerned with attitude, noise sensitivity, directive effects, secondary effects, annoyance and attempts to lower noise level exposed. From the field survey, the doseresponse relationship of community response to aircraft noise was established and there are different characteristics between civil and military aircraft. Though the study is still continuing on a few interest, one among some results is that %HA (%highly annoyed) of civil aircraft is higher than military's under the 70 WECPNL.

• Journal of Platform Technology
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• v.9 no.3
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• pp.24-35
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• 2021

High-speed military aircraft shall be able to identify and resolve enemy threats or internal component defects with survival equipment and warning systems to minimize casualties. Warning system is divided into visual method with symbolic display and auditory method with communication equipment, which is superior in that they it has a short response time and does not cause pilot confusion by listening to simple messages. Thus, this paper suggested and evaluated effective design methods of voice/tone warning systems for military aircraft based on a life cycle perspective. Since military aircraft is safety-sensitive, priorities and three properties(Inhibitible, Interruptible, and Deactivatable) were applied to each warning to reflect criticality and urgency. As a result, we confirmed that it took 40ms to play the voice warnings, satisfying all requirements through V model-based development and testing, and improving product reliability.