• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.253-258
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• 2012

In this study, designs of the high efficiency composite propeller blade for a high speed turboprop aircraft, which will be used for a next generation regional commercial aircraft in Korea, are performed. Both the vortex theory and the blade element theory are used for preliminary aerodynamic design and performance analysis of the propeller. Then the aerodynamic design result is confirmed through performance analysis using a commercial CFD code, ANSYS. The carbon/epoxy composite materials is used, and the skin-spar-foam sandwich type structure is adopted for improvement of lightness and structural stability. Finally, it is investigated that the proposed propeller blade has high efficiency and structural safety through both aerodynamic and structural analysis and experimental test of a prototype propeller blade.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.8
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• pp.50-55
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• 2005

An advanced method of Relaxed Static Stability (RSS) is utilized for improving the aerodynamic performance of modern version supersonic jet fighter aircraft. The laws of flight control system utilize RSS criteria in both longitudinal and lateral-directional axes to achieve performance enhancements. Particularly, the design of longitudinal control laws for utilizing RSS methods greatly affects the performance of the aircraft in Air-to-Air Tracking and Air-to-Ground modes, which improves weapon delivery. In the area of Air-to-Air Tracking, the development of longitudinal control laws aids in the fine tracking and gross acquisition of other aircraft. This paper proposes that new concept of longitudinal control law introduce in order to improve fine tracking performance in air-to-air tracking maneuver. Result of HQS pilot simulation and flight test, fine tracking performance improve without degradation of gross acquisition when new concept of control law is applied.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.7
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• pp.713-718
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• 2006

Supersonic jet fighter aircraft have several different weapon loading configuration to support air-to-air combat and air-to-ground delivery of weapon modes. Especially, asymmetric loading configurations could result in decreased handling qualities for the pilot maneuvering of the aircraft. The design of the T-50 lateral-directional roll axis control laws change from beta-betadot feedback structure to simple roll rate feedback structure and gains such as F-16 in order to improve roll-off phenomena during pitch maneuver in asymmetric loading configuration. Consequently, it is found that the improved control law decreases the roll-off phenomenon in lateral axes during pitch maneuver, but initial roll response is very fast and wing pitching moment is increased. In this paper, we propose the lateral control law blending between beta-betadot and simple roll rate feedback system in order to decreases the roll-off phenomenon in lateral axes during pitch maneuver without degrading of roll performance.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.29 no.2
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• pp.55-66
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• 2021

ICAO recommended that airspace monitoring and periodic safety assessments in each Contracting State ensure the stability of the airspace, since reducing the aircraft lateral and vertical separation intervals would rather increase the risk of collision. The target level of safety of the AKARA-FUKUE Corridor at the southern end of Jeju was 247×10^-9. In simple comparison, this means that the risk of an aircraft collision in this area (international safety standards, 5.0×10^-9) is about 50 times higher. The scope of this study is to organize the concept of terms, analyze the air traffic volume, the current status of navigational safety facility usage fees, and investigations of an aircraft collision risk in Jeju southern air corridor. Analyzing government policies and overseas evaluations, revising some of the existing contents, presenting some of the additional contents of new routes, and changing the instrument procedure for Korean-Chinese routes, change of arrive/departure route between Incheon Airport and Shanghai Airport, reduce the risk of aircraft collisions. We hope to restore airspace sovereignty, contribute to policies for the government to take the lead in solving this problem, and expect stability and operational efficiency in air traffic.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.194-197
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• 2017

Aircraft engine and auxiliary power units are certified in processes of design, production according to airworthiness requirements. The aircraft engines shall demonstrate compliance with the design and production through the Type Certificate and the auxiliary power unit shall demonstrate compliance with the design and production through the Technical Standards Order Approval. MOLIT(Ministry of Land, Infrastructure and Transport) established the law and the airworthiness requirements for aircraft engines such as KAS Part 33 but didn't issue the Technical Standards Order for auxiliary power unit. In this paper, we proposed and explained the plan for improvement of our aircraft engines industry through building and expanding the certification infra-structure for aircraft engines and auxiliary power unit.

• Journal of Aerospace System Engineering
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• v.13 no.5
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• pp.65-71
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• 2019

In this study, as a part of the aging aircraft performance improvement project for which no design information is provided, a new type of blade antenna is installed on the main part of the aging aircraft, and the method of proving the fatigue life of the main part of the aircraft is reviewed and summarized. There are various methods to prove fatigue life according to the manufacturer and aircraft design conditions. The fatigue life prediction and damage tolerance range of the relevant site were obtained through related regulations and industry examples. From these results, the fatigue life of newly installed antennas around the main parts of the aging aircraft was evaluated and the maintenance period and criteria were set according to the damage tolerance.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.3
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• pp.242-253
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• 2011

The typical missions for the current stand-off UAVs are surveillance and reconnaissance. On the other hand, the primary mission for the future UCAS will be combat mission such as SEAD under the man-made ultimately hostile environment including SAM, antiaircraft artillery, threat radar, etc. Therefore, one of the most important challenges in UCAS design is improvement of survivability. The current studies for aircraft combat survivability are focused on the improvement of susceptibility and vulnerability of manned aircraft system. Although the survivability design methodology for UCAS might be very similar to the manned combat system but there are some differences in mission environment, system configuration, performance between manned and unmanned systems. So the parameters and their sensitivities which affect aircraft combat survivability are different in qualitatively and quantitatively. The susceptibility related parameters for F-16 C/D and X-45A as an example of manned and unmanned system are identified and the susceptibility parameter sensitivities are analyzed by using Monte-Carlo Simulation in this study.

• Smart Media Journal
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• v.10 no.3
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• pp.54-59
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• 2021

Flight data acquired through flight instrumentation equipment during aircraft development play an important role in aircraft development and performance improvement. Therefore, as the reliability of flight instruments is required, inspection systems to check the soundness of flight instruments are very important. In this paper, we analyze the existing test system for flight data instrumentation equipment and present improvements in the hardware and software aspects of the test system. Based on this, we design and implement a test system with improved performance and present test results. Test system with improved performance improves cost savings, flexible application, and maintenance compared to the existing test system. Therefore, the robustness of the instrumentation equipment can be obtained, which can be expected to improve the reliability of flight data.

• Journal of computational fluids engineering
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• v.17 no.4
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• pp.56-68
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• 2012

Nowadays, Unmanned Combat Air Vehicle(UCAV) has become an important aircraft system for the national defense. For its efficiency and survivability, shape optimization of UCAV is an essential part of its design process. In this paper, shape optimization of UCAV was processed for aerodynamic performance improvement and Radar Cross Section(RCS) reduction using Multi Objective Genetic Algorithm(MOGA). Lift and induced drag, friction drag, RCS were calculated using panel method, boundary layer theory, Physical Optics(PO) approximation respectively. In particular, calculation applied Radar Absorbing Material(RAM) was performed for the additional RCS reduction. Results are indicated that shape optimization is performed well for improving aerodynamic performance, reducing RCS. Further study will be performed with higher fidelity tools and consider other design segments including structure.

• Journal of the Korea Institute of Military Science and Technology
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• v.25 no.3
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• pp.267-274
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• 2022

The Republic of Korea has a close cooperative relationship with NATO, of which the United States is a member. NATO is encouraged to follow UHF coalition waveforms for military air operations(SATURN) as defined in STANAG 4372. SATURN is a high-speed frequency hopping waveform with enhanced anti-jamming and security functions. Plans to improve the performance of existing military aircraft with air to ground radios to which SATURN function is applied. IFF case analysis and MRT evaluation plan were established to present an efficient test and evaluation plan for air to ground radios.