• Journal of Advanced Navigation Technology
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• v.25 no.1
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• pp.52-59
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• 2021

According to the International Air Transport Association (IATA), 61% of the accidents occurred during the approach and landing phase of the flight, with 16% of the accidents caused by unstable access of the commercial aircraft. It was identified that the pilot's unstable approach and poor manipulation of correction led to accidents by continuing the excessive approach without go-around manuever. The causes of unstable access may vary, including airport approach procedures, pilot error, misplanning, workload, ATC (Air Traffic Contol) congestion, etc. In this study, we use the flight data analysis system to select domestic case airports and aircraft type where unstable approach events occur repeatedly. Through flight data analysis, including main events, airport approach procedures, pilot operations, as well as various environmental factors such as weather and geographical conditions at the airport. It aims to identify and eliminate the tendency of unstable approach events and the causes and risks of them to derive implications for mitigating unstable approach events and for developing navigation safety measures.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.513-520
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• 2004

A steady-state/transient performance simulation model was newly developed for the propulsion system of the CRW (Canard Rotor Wing) type UAV (Unmanned Aerial Vehicle) during flight mode transition. The CRW type UAV has a new concept RPV (Remotely Piloted Vehicle) which can fly at two flight modes such as the take-off/landing and low speed forward flight mode using the rotary wing driven by engine bypass exhaust gas and the high speed forward flight mode using the stopped wing and main engine thrust. The propulsion system of the CRW type UAV consists of the main engine system and the duct system. The flight vehicle may generally select a proper type and specific engine with acceptable thrust level to meet the flight mission in the propulsion system design phase. In this study, a turbojet engine with one spool was selected by decision of the vehicle system designer, and the duct system is composed of main duct, rotor duct, master valve, rotor tip-jet nozzles, and variable area main nozzle. In order to establish the safe flight mode transition region of the propulsion system, steady-state and transient performance simulation should be needed. Using this simulation model, the optimal fuel flow schedules were obtained to keep the proper surge margin and the turbine inlet temperature limitation through steady-state and transient performance estimation. Furthermore, these analysis results will be used to the control optimization of the propulsion system, later. In the transient performance model, ICV (Inter-Component Volume) model was used. The performance analysis using the developed models was performed at various flight conditions and fuel flow schedules, and these results could set the safe flight mode transition region to satisfy the turbine inlet temperature overshoot limitation as well as the compressor surge margin. Because the engine performance simulation results without the duct system were well agreed with the engine manufacturer's data and the analysis results using a commercial program, it was confirmed that the validity of the proposed performance model was verified. However, the propulsion system performance model including the duct system will be compared with experimental measuring data, later.

• Bulletin of the Korean Space Science Society
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• 2004.10b
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• pp.372-375
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• 2004

The UV radiometer payload was launched successfully from the west coastal area of Korea Peninsula aboard KSR-III on 28, Nov 2002. KSR-III was the Korean third generation sounding rocket and was developed as intermediate step to larger space launch vehicle with liquid propulsion engine system. UV radiometer onboard KSR-III consists of UV and visible band optical phototubes to measure the direct solar attenuation during rocket ascending phase. For UV detection, 4 channel of sensors were installed in electronics payload section and each channel has 255, 290, 310nm center wavelengths, respectively. 450nm channel was used as reference for correction of the rocket attitude during the flight. Transmission characteristics of all channels were calibrated precisely prior to the flight test at the Optical Lab. in KARI (Korea Aerospace Research Institute). During a total of 231s flight time, the onboard data telemetered to the ground station in real time. The ozone column density was calculated by this telemetry raw data. From the calculated column density, the vertical ozone profile over Korea Peninsula was obtained with sensor calibration data. Our results had reasonable agreements compared with various observations such as ground Umkhr measurement at Yonsei site, ozonesonde at Pohang site, and satellite measurements of HALOE and POAM. The sensitivity analysis of retrieval algorithm for parameters was performed and it was provided that significant error sources of the retrieval algorithm.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.265-270
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• 2006

Recently, inertial sensors like gyros and accelerometers have been quite miniaturized by Micro Electro-Mechanical Systems (MEMS) technology. JAXA is developing a MEM-based GPS/INS hybrid navigation system named Micro-GAIA. The navigation performance of Micro-GAIA was evaluated through off-line analysis by using flight test data. The estimation errors of the roll, pitch, and azimuth were $0.03^{\circ}$, $0.05^{\circ}$, $0.05^{\circ}$ $(1{\sigma})$, respectively. he horizontal position errors after 60-second GPS outages were reduced to 25 m CEP. The attitude errors and position errors are nearly half of ones reported previously[2]. Furthermore, using the adaptive Kalman filters, the robustness against the uncertainty of the measurement noise was improved. Comparing the innovation-based and residual-based adaptive Kalman filters, it was confirmed that the latter is robuster than the former.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.23 no.1
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• pp.30-40
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• 2015

Recently, the need of RPA(Remotely Piloted Aircraft) pilots is increasing rapidly with many requirements in order to be a beginner RPA pilot, including basic flight training, instrument flight qualification training, and aircraft type switching training. When RPA pilot gets disqualified, there will be generated much waste of efforts and expenses of trainees those pilots who are disqualified. Therefore, the methodology of pre-verifying those pilots who are not proper as RPA pilots through various scientific methods will save time and expenses with pre-reducing the pilots who will get disqualified later on. The methodology of aptitude test of RPA pilots is laid out as a consideration of pre-study of RPA pilots work analysis, and select types of aptitude test. A suitability of aptitude test is verified. In order to diagnose the flight aptitude precisely, it requires to be developed. Flight aptitude test tools might be connected with training program which could foster piloting aptitude with pre-diagnosing RPA pilot trainee selecting process. For that reason, we made an experiment in order to verify credibility and suitability of these selected programs with developing RPA pilot aptitude test tools. And also, we analyzed relationships among characteristics, analysis of data, and variables to verify the efficiency of data from prior experiment. Through this thesis, we expect to raise efficiency of flight training by providing pre-flight aptitude test information of RPA pilots.

• Journal of the Korean Society of Propulsion Engineers
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• v.12 no.3
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• pp.49-59
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• 2008

In this study, the design method of a 155 mm Solid Fuel Ramjet projectile is proposed and a flight performance analysis program through mathematical modelling is developed. Through flight performance analysis, ramjet performance during flight, which is comprised of thrust, specific impulse, pressure recovery ratio, location of shock waves, and magnitude of drag, was predicted. The results show that compared to Rocket Assisted Projectile(RAP), the range was increased by 90 %. Furthermore, how variations in nozzle exit area ratio and the intake area cause variations in range was observed. This research on modeling and simulation methodology will provide useful data for future development of solid fuel ramjet projectiles.

• Journal of Biosystems Engineering
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• v.36 no.6
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• pp.467-475
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• 2011

Aerial spraying technology using a small unmanned helicopter is an efficient and practical tool to achieve stable agricultural production to improve the working condition. An attitude controller for the agricultural helicopter would be helpful to aerial application operator. In order to construct the flight controller, a state space model of the helicopter should be identified using a dynamic analysis program, such as CIFER$^{(R)}$. To obtain the state space a model of the helicopter, frequency-sweep flight tests were performed and time history data were acquired using a custom-built stick position transmitter. Four elements of stick commands were accessed for the collective pitch (heave), aileron (roll), elevator (pitch), rudder (yaw) maneuvers. The test results showed that rudder stick position signal was highly linear with rudder input channel signal of the receiver; however, collective pitch stick position signal was exponentially manipulated for the convenience of control stick handling. The acquired stick position and flight dynamic data during sweep tests would be analyzed in the followed study.

• Journal of Climate Change Research
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• v.9 no.4
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• pp.313-318
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• 2018

The growth rate of international aviation is expected to be higher than that of most industries and the proportion of carbon emissions from the aviation industry will become very significant as the year 2050 approaches. Constraining the growth of this industry is not desirable because it is essential for human welfare as well as the development of related industries. However, reduction of carbon due to aviation is not easy because it is difficult to improve fuel efficiency in a significant way. The ICAO (International Civil Aviation Organization), which is the main organization responsible for handling this problem, developed a program named CORSIA (Carbon Offsetting and Reduction Scheme for International Aviation). The present study analyzes various strategies for countries and airlines to comply with CORSIA using a fuel-efficient system. We conclude that countries should improve their airspace utilization systems, airport facilities, and air navigation systems. Additionally, based on the results of a flight data analysis, airlines should improve their operational efficiency in terms of operations control, flight operation, and maintenance management.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.520-522
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• 2011

위성으로부터 전송받은 Telemetry 플레이백 데이터 파일들을 적절한 크기로 또는 저장된 시간에 따라 병합하거나 분할할 수 있는 플레이백 파일 병합/분할 프로그램을 구현하였다. 기존에 플레이백 데이터가 정상적으로 수신되었는지를 점검하기 위한 플레이백 데이터 자동 분석 프로그램이 있는데, 기존의 프로그램을 윈도우 기반으로 보다 편리하게 사용할 수 있도록 전체적으로 보완하였고, 여기에 플레이백 파일 병합/분할 기능을 추가하여 전체적으로 하나로 통합하였다. 본 논문은 차세대 저궤도 위성에서 수행되는 데이터 저장 및 전송에 대한 내용과 새롭게 개선된 플레이백 데이터 자동분석 프로그램 및 플레이백 파일 병합/분할 프로그램에 대해 기술한 것이다.

• Journal of Advanced Navigation Technology
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• v.28 no.1
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• pp.15-20
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• 2024

The utilization of small unmanned aerial vehicles (UAVs) has expanded into both military and civilian domains, increasing the necessity for research to ensure operational safety and the efficient utilization of airspace. In this study, the calculation of minimum separation distances for the safe operation of small UAVs at low altitudes was conducted. The determination of minimum separation distances requires a comprehensive analysis of the total system errors associated with small UAVs, necessitating sensitivity analysis to identify key factors contributing to flight technology errors. Flight data for small UAVs were acquired by integrating the control system of an actual small UAV with a flight simulation program. Based on this data, operational scenarios for small UAVs were established, and the minimum separation distances for each scenario were calculated. This research contributes to proposing methods for utilizing calculated minimum separation distances as crucial parameters for ensuring the safe operation of small unmanned aerial vehicles in real-world scenarios.