• The Journal of Aerospace Industry
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• s.65
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• pp.70-88
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• 2003

필자가 참여했던 쌍발복합재사업, 쌍발복합재항공기사업, SB427 민수용헬기사업, T-50 초음속고등훈력기 사업을 통해 복합재료의 항공기 적용사례를 고찰하면서, 쌍발복합재항공기는 실험용항공기(Experimental Aircraft)이지만 국내 최초의 전복합재항공기(All-composites Aircraft)로서 항공기 구조물이 순전히 복합재료만을 이용하여 설계 및 제작이 가능하다는 것을 보여주었고, 복합재료를 적용 시 어떠한 이점이 있는지를 보여준 예가 되고 있다. SB427 민수용헬기사업은 헬리콥터에서 로터 블레이드와 동체 등 기체구조물 대분에 왜 복합재료를 사용해야 효과적인 지를 잘 보여주고 있다. SB427 개발 사업을 통해 얻을 수 있는 또 다른 점은 민수용 항공기의 경우 구축된 복합재료 인증체계에 따라 복합재구조물을 개발해야 되고 그래야만 마케팅에서 신뢰를 얻을 수 있다는 것이다. T-50 항공기는 국내에서 최초로 개발된 초음속기로 미익 부문에 복합재료가 응용되었다. 양산 항공기의 주구조물에 복합재료가 쓰인 예는 T-50이 첫 번째 인데 T-50에서 얻어진 복합재 적용기술은 앞으로 개발될 고급 군용기와 민수용기에 널리 활용될 것으로 기대된다. 본 논문에서는, 국내 개발 항공기에서의 복합재료 적용이라는 특정 주제를 중심으로 개발 이력과 기술적 조망을 통하여, 정부, 연구소, 업체 간의 유기적이고 체계적인 전략이 필요하다고 사료되며, 이러한 전략을 바탕으로 효율적인 항공 산업을 선점해야 할 것이다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.3
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• pp.93-100
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• 2006

Modern versions of supersonic jet fighter aircraft using a digital flight-by-wire flight control system design utilizes a control surface reconfiguration in order to guarantee the aircraft flight stability when a control surface is failed. The T-50 flight control laws are designed such that the surface reconfiguration mode controls the aircraft using non-failed control surfaces when one of the control surfaces is failed. In this paper, linear analysis and HQS(Handling Quality Simulator) pilot simulations are performed to analyze the flight stability and handling quality when the surface reconfiguration mode is engaged for aircraft landing configuration. It is found that the aircraft flight stability and handling quality is satisfied to level 1 requirements when the T-50 flight control law is changed to the surface reconfiguration mode.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.5
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• pp.57-64
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• 2005

Modern versions of supersonic jet fighter aircraft using digital flight-by-wire flight control system receive aircraft flight condition such as altitude, airspeed and AoA(angle of attack) from IMFP(Integrated Multi-Function Probe). IMFP sensors data have triplex structure using three IMFP sensors. An air data reconfiguration mode is applied to a T-50 flight control law to guarantee the aircraft flight stability when 2 or 3 IMFP sensors data are invalided. In this study, linear analysis and HQS(Handling Quality Simulator) pilot simulation are performed to analyze flight stability when the air data reconfiguration mode is applied to the control law. And we propose an example that the air data reconfiguration mode is applied to the control law due to second failure of IMFP during T-50 flight. It is found that the aircraft flight stability is not affected when the T-50 flight control law is changed to the air data reconfiguration mode.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.10
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• pp.948-956
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• 2007

It is important during FSD(Full Scale Development) period to verify whether the aircraft system function meets the aircraft requirements and functional performance. Especially, the functionality of the integrated propulsion system should be verified to evaluate the compatibility with aircraft. Various flight tests such as the engine airstart test, the engine horsepower extraction test, the backup throttle functionality test had been performed to evaluate the engine/aircraft compatibility with T-50 during FSD period. Through such flight tests, it was confirmed that the propulsion system of T-50 was properly designed and installed to the aircraft. This paper shows description on each flight test item, test procedure and test results. It is expected that this paper could be a reference for preparing the propulsion flight test in other aircraft developments.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.1564-1568
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• 2004

The requirements of internal balance were studied that should be considered on performing force & moment transonic wind tunnel testing to develop combat aircraft. In many insecure factors of test condition, uncertainty analysis was conducted to verify one drag count measurements. The analysis result was applied to T-50 aircraft model and compared for data verifaction. In conclusion, the aerodynamicist should estimate the validation and accuracy of test data by having an overall grasp of system components including internal balance. It will help him get high productivity of testing and effective validated data at tunnel.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.7
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• pp.85-91
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• 2005

Supersonic jet fighter aircraft must have been guaranteed appropriate for controllability and stability in HAoA(High Angle of Attack) region. Limit value of aircraft enter the deep stall at HAoA is related to problem of aircraft configuration design. But, In order to guarantee the aircraft safety in HAoA, control law is designed using digital Fly-By-Wire flight control system in modern versions of supersonic jet fighter aircraft. Also, In order to recovery if aircraft enter the deep stall or spin, anti-spin control law and MPO(Manual Pitch Override) mode is designed. AoA limiter and MPO is designed in longitudinal axis and HAoA departure prevention logic, roll command limiter, rudder fader and anti-spin logic is designed in lateral-directional axis. In this paper, we introduce the T-50 HAoA flight control law and propose that aircraft stability and adequate of these control law from HAoA flight test.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.9
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• pp.773-778
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• 2014

Aircraft communication system which provides internal communications between pilots in an aircraft and external communications between pilots and operators in ground tower with them. It is very important equipment in terms of mission and safety. It wouldn't meet performance requirements with only functions of transmission and receiving of signals. It should provide highly clear voice quality without any noise. This paper analyzes the cause of noise during internal communications and summarizes the design changes applying single point ground concept to solve the problem. It also describes the results of fight test to verify the design changes.

• 시스템엔지니어링워크숍
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• s.6
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• pp.153-156
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• 2005

• 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 the Korean Society for Aeronautical & Space Sciences
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• v.34 no.6
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• pp.83-91
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• 2006

An advanced method of Relaxed Static Stability (RSS) is utilized for improving the aerodynamic performance of modern version supersonic jet fighter aircraft. The flight control system utilizes RSS criteria in longitudinal axis to achieve performance enhancements and improve stability. The flight control law of T-50 advanced trainer employs RSS concept in order to improve the aerodynamic performance and guarantee aircraft stability. The longitudinal center of gravity(X-c.g) varies as a function of external stores, fuel state and gear position. Shifts in X-c.g relate directly to longitudinal static margin in aircraft stability. This paper deals the maximum aft X-c.g for critical aircraft loadings and checks static margin limits using sensitivity such as damping, natural frequency, gain and phase margin. And nonlinear analysis was conducted for such as short period input. And also, this paper shows the T-50 aircraft stability based on the result of high angle of attack flight such as upright and inverted departure.