• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.2
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• pp.82-89
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• 2006

The flutter/vibroacoustic characteristics can be acquired by conducting flight tests with various conditions for a long period of test. Accordingly it is indispensable to build a specially designed database system to efficiently accumulate the enormous data obtained from flight tests. Hence, T-50 Flight Test Database System(FTDS) based on MS-Access is developed to handle the flutter/vibroacoustic environment data obtained from flight tests. The developed system is structured with the items related to aircraft flight test, the tables composed of the relevant items and a relational database logically connecting the tables. The T-50 FTDS is implemented with data searching GUI(Graphic User Interface) programed with Visual Basic and Structured Query Language to make intuitive searches over the stored data. The developed system has been used for accumulating the flutter/vibroacoustic data and verifying vibroacoustic Specifications.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.2
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• pp.173-180
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• 2014

In this paper, the instrument flight certification process and flight test results of Korean Utility Helicopter (KUH) are presented. For the instrument flight certification, the suitability of installed equipments and instruments have been reviewed and verified by ground and flight tests. Next, static and dynamic stability test are conducted in accordance with FAR-29 Appendix B. The static stability is determined by the change of speed and attitude according to control inputs. The dynamic stability is evaluated by how quickly the response of the helicopter due to long and short period control inputs are decreased. The pilot workload evaluation are also carried out by simulated IMC flight tests. This paper presents the workload assessment results when some failures are occurred at cockpit instruments, engine or flight control systems as well as the normal situation. After the simulated IMC flight test is completed, actual instrument flight test are conducted in a real IMC environment according to the air traffic controls.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.479-488
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• 2019

The flight test operational procedure artifact includes mission planning, execution methods, and safety measures for each step of test progress. As the development of guided missiles has become more advanced and strategic, flight test has become increasingly complex and broadened. Therefore, increased reliability of the flight test operation procedures was required to ensure test safety. Particularly, the design of the flight test operational procedures required verification through M&S to predict and prepare for the uncertainty in a new test. The relevant studies have published the optimal framework development for flight tests and the model-based improvements of flight test processes, but they lacked the specificity to be applied directly to the flight test operational procedures. In addition, the flight test operational procedures, which consist of document bases, have caused problems such as limitations of analysis capabilities, insensitive expressions, and lack of scalability for the behavior and performance analysis of test resources. To improve these problems, this paper proposes how to design operational procedure of guided missile flight test system by applying MBSE(Model-based Systems Engineering). This research has improved reliability by increasing the ability to analyze the behavior and performance of test resources, and increased efficiency with the scalability applicable to multiple flight tests. That can be also used continuously for the guided missile flight tests that will be developed in the future.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.10
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• pp.781-787
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• 2016

We introduce FEST (Flight Environment Simulation Test) procedures for precise guided missiles to reliably improve systems. Flight vibration specification was established based on power spectral density curves calculated from flight test data of a high speed precise guided missile. A FEST pre-profile was developed according to flight vibration specification and delivered to a precise guided missile assembly. Vibration responses were measured by installing accelerometers on electronic components vulnerable to dynamic forces. The FEST profile was adjusted by comparing the vibration responses and the flight vibration specification. Subsequently, the FEST profile was repeatedly modified through trial and error, because the responses were similar to the flight environment. The modified FEST profile enabled performance testing of assembled precise guided missiles under simulated flight conditions on the ground, where unexpected errors could be corrected before the flight tests, leading to cost and risk reduction in the development of the precise guided missile system.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.8
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• pp.1487-1494
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• 2002

In this study, to propose the prediction method of the crack growth under flight-simulation loading, crack growth tests are conducted on 2124-7851 aluminum alloy specimens. The prediction of crack growth under flight-simulation loading is performed by the stochastic crack growth model which was developed in previous study. First of all, to reduce the complex load history into a number of constant amplitude events, rainflow counting is applied to the flight-simulation loading wave. The crack growth, then, is predicted by the stochastic crack growth model that can describe the load interaction effect as well as the variability in crack growth process. The material constants required in this model are obtained from crack growth tests under constant amplitude loading and single tensile overload. The curves predicted by the proposed model well describe the crack growth behavior under flight-simulation loading and agree with experimental data. In addition, this model well predicts the variability of fatigue lives.

• Journal of Aerospace System Engineering
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• v.10 no.1
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• pp.111-117
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• 2016

A new configuration of tiltrotor UAV previously suggested by Korea Aerospace Research Institute (KARI) for the purpose of increasing the endurance performance in airplane mode flight has extended wings attached to the nacelle and rotated with the nacelle according to the flight modes. In this research, the effectiveness of the extended wing on the enhancement of the endurance performance of KARI tiltrotor UAV (TR60) was analytically investigated based on CFD analysis results. Flight tests and ground tests of measuring the fuel consumption were also conducted to directly compare the endurance performance for the two configurations of TR60 baseline and TR60 extended-wing model.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.268-277
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• 2019

Flight test systems should monitor various conditions in real time during flight tests and take safety measures in an emergency. The importance of ensuring test safety increases in more complicated and wider test environments. Also, due to the transition of wartime operational authority, many guided missile systems must be developed simultaneously. Early deployment and budget reduction by shortening the development and T&E periods are also necessary. Consequently, the risk of flight tests under the circumstance of inefficient test resources is increasing. To address this deficiency, a flight test system model using SysML was proposed in this study. The method of designing and verifying the test system is based on the agile shift left testing methodology of advanced T&E labs and utilizing a system reference model in the aerospace field. Through modeling and simulation analysis, early identification and correction of faults resulting from inconsistent test requirements can mitigate the risk of delays during the T&E phase of flight tests. Also, because the flight test system model was constructed using SysML, it can be applied to test various guided missile systems.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.5
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• pp.349-357
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• 2022

Since the flight control computer of unmanned aerial vehicle (UAV) is a flight critical equipment, it is necessary to ensure reliability and safety from the development step, and a redundancy-based fault management design is required in order to operate normally even a failure occurs. To reduce cost, weight and power consumption, the dual-redundant flight control system design is considered in UAV. However, there are various restrictions on the fault management design. In this paper, we propose the fault detection and isolation designs for the dual-redundant flight control computer to satisfy the safety requirements of an UAV. In addition, the flight control computer developed by applying the fault management design performed functional tests in the integrated test environment, and after performing FMET in the HILS, its reliability was verified through flight tests.

• Journal of the Korea Society for Simulation
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• v.29 no.1
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• pp.1-9
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• 2020

The ballistic missile threat continues to increase with the proliferation of missile technology. In response to this threat, many kinds of interceptors have been emphasized over the years. For development of interceptor, systematic flight tests are essential. Flight tests provide valuable data that can be used to verify performance and confirm the technological progress of ballistic missile defense system including interceptor. However, during flight tests, civilians near the test region could be risk due to a lot of intercept debris. For this reason, reliable estimate of safety area for the flight tests should be preceded. In this study, prediction of safety area is performed through modeling and simulation. Firstly, behaviors of ballistic missile and interceptor are simulated for those entire phase including interception to obtain the relative intercept velocity and the relative impact angle. By using obtained data of kinetic energy, the fragment ejection velocity is calculated and fragment trajectories are simulated by considering drag, gravity and wind effects. Based on the debris field formation and hazard evaluation of debris, final safety area is calculated.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.13 no.1
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• pp.1-8
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• 2005

The purpose of the study is to show the need for the development of standard materials which can be used for flight training and pilot practical tests in the future. In this paper the flight training and evaluation references of flight training institutes certified by the Ministry of Construction and Transportation(MOCT) are compared with references of the international organization such as ICAO and FAA. As a result it is found that the flight schools certified by the MOCT have used different references for flight training and evaluation. Therefore, this study suggests creation and operation of an expert advisory group to develop new standards for flight training and evaluation, so called " Flight Training Manual", in Korea.