• Journal of the Korea Institute of Military Science and Technology
• /
• v.15 no.6
• /
• pp.746-753
• /
• 2012

ROK military helicopters are frequently exposed to the hazard situations due to the characteristic of operation. Especially, helicopter accident may lead to critical damage of human and structure. Accordingly, pilots have to train the autorotation procedures and learn the skill to prevent hard landing. In this paper, the behavior of skid gear subject to the helicopter autorotation was conducted by using numerical method. The computer simulation approach by using finite element method was employed to accomplish this goal. Additionally, the behavior of skid gear was evaluated for the different landing conditions. In conclusion, the maximum stress concentration was occurred at the attached area of skid cross-tube to the fuselage. Also, it was revealed that the most proper attitude was level landing to prevent hard landing.

• Journal of Advanced Navigation Technology
• /
• v.27 no.2
• /
• pp.155-161
• /
• 2023

Vertigo refers to a state in which awareness related to the location, posture, movement, etc. of a helicopter is insufficient in space. It is easy to fall into flight illusion when flying in dense fog or night flight, and even if it has a wide field of view, it can be caused by visual causes such as cloud shapes, wind conditions, conditions of ground objects, and sensory causes such as changes in air posture or gravitational acceleration. The design and program of the motion system are studied that applied a six-axis motion system to a conventional commercial flight simulator program for pilot training, depending on the specificity of helicopter flight training that requires perception and sensitivity. Using the motion-based helicopter simulator produced in this study to train pilots, it is expected to have a positive effect in prevent of vertigo, where high performance could not be confirmed in the previously used visual-based simulation training device.

• Journal of Advanced Navigation Technology
• /
• v.27 no.3
• /
• pp.247-254
• /
• 2023

GAIN in the US explained in its Pilot/Controller Collaboration Initiatives report that "pilots and air traffic controllers talk to each other all day long, but they rarely communicate." The starting point for the study was the question of whether differences in flight safety perceptions and culture between pilots and air traffic controllers, or other factors, could lead to mutual misunderstandings of procedures and instructions. Digest with The many processes that must be solved within tight deadlines increase the likelihood of accidents through cascading risk factors such as James Reason's Swiss Cheese Theory. Despite the fact that the pilot-air traffic controller complex, which is the subject of flight, occupies a considerable part, there is no integrated management for safe operation between the two groups. Therefore, this research aims to achieve integrated management of safety and education for safe operation between pilots and air traffic controllers through JCRM..

• Journal of the Korea Society for Simulation
• /
• v.21 no.4
• /
• pp.25-33
• /
• 2012

Armed helicopter is an integral part of armed forces, which conducts vital missions, such as anti-armor attack, close air support, escorting air assault operations, and reconnaissance. A typical cockpit arrangement of armed helicopters has been a tandem configuration. This is to reduce the frontal area, which in turn increases the forward speed as well as reduces the chance of being hit by enemy fires. However, many armed helicopters in the world are now being developed as a side-by-side configuration. Such configuration is quite different from the conventional cockpit arrangement in light of the crew communications and situational awareness. Therefore, the main objective of this study is to find the optimized combination of mission tasks among pilots in a side-by-side configuration cockpit by measuring the workload using the NASA Task Load Index method. The experimental results indicate that the workload of crew members differ as disparate tasks are being performed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2005.05a
• /
• pp.132-137
• /
• 2005

This paper addresses what amount of whole-body vibration is exposed to pilots of UH60 helicopters during flight. To measure the whole-body exposed from the feet and seat, the 12-axis vibration measurement system was used. It enables simultaneous measurement of vibration exposure from the body contact area of the feet, hip and back. The measured 12-axis vibration signals are exploited to the comfort level of UH60 helicopters during flight. It is shown that the evaluated ride value is close to $0.74{\sim}0.79m/s^2$ and that it is equivalent to the semantic scale of 'fairly uncomfortable'. To assess the health effects of whole-body vibration exposed to pilots of UH60 helicopters during their flight, the rms-based and VDV(vibration dose value)-based evaluation results of measured four-axis vibration signals are shown in this work. The fatigue-decreased proficiency limit, whose level is half of the exposure limit, is expected to come after the two-hour flight. The exposure limit is shown to reach after the 10-hour flight.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.1
• /
• pp.159-164
• /
• 2016

This paper reports the load factor logic design for a fly-by-wire helicopter flight envelope protection. As a helicopter is very complex system with a rotor, fuselage, engine, etc., there are many constraints on the flight region. Because of these constraints, pilots should consider them carefully and have a heavy workload, which causes controllability degradation. In this respect, automatic logic is needed to free the pilot from these considerations. As one of these logics, the flight envelope protection logic for the load factor of a FBW helicopter was designed. The flight to exceed the load factor is caused by an abrupt pitch cyclic stick change. In this scheme, the load factor limit logic was added between the pilot stick command block and pitch attitude command block. From the current load value, the available attitude range was calculated dynamically and simulated on the helicopter simulator model to verify the performance. A comparison of the simulation results at the hovering and forward speed region with and without applying the load limiting logic showed that the load factor limit was exceeded more than 20% when the logic was not applied, whereas with the load factor limit logic the load factor was within the limit. In conclusion, a dynamically allocated limitation logic to helicopter FBW controller was verified by simulation.

• Fire Science and Engineering
• /
• v.26 no.2
• /
• pp.97-104
• /
• 2012

Forest fires were easy to be larger in Korea. So the utilization of aircrafts, especially helicopters, for forest fire attack would be increased gradually. In the forest fire attack process, the improvement of the helicopter aerial fire attack technique and safety were the chief element for efficient forest fire attack. In this study, we surveyed the recognition of pilots who worked in Forest Aviation Office which was responsible for aerial forest fire attack in Korea. Using these survey results, we suggested more efficient and safer method for aerial fire fighting based on actual experience of air attack at the scene of forest fire burning.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.50 no.2
• /
• pp.103-110
• /
• 2022

Degradation of handling qualities(HQs) due to bad weather or mechanical failure can pose a fatal risk to pilots unfamiliar with such situation. In particular, icing is an important issue to consider as it is a frequent cause of accidents. Most of the previous research works focuses on aerodynamic performance changes due to icing and the corresponding icing modeling or methods to prevent icing, whereas the present work attempts to actively compensate for HQ degradation due to icing on a full-scale helicopter through flight control law design. To this end, the present work first demonstrates HQ degradation due to icing using CONDUIT software, and subsequently presents a robust control design via the RS-LQR(Robust Servomechanism Linear Quadratic Regulation) procedure to compensate for the HQ degradation. Simulation results show that the proposed robust control maintains Level 1 HQ in the presence of icing.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.25 no.3
• /
• pp.108-114
• /
• 2017

A flight simulator is an instrument which lets pilots attain proficiency of handling various emergency situations, and the sense of flying. In this thesis, current status of domestic simulators will be stated, and after showing the problems with the present management of these simulators, comparisons of how and what kind of facilities they are managed around the globe will be made. After comparing and analyzing the difference in the way the simulators are ran, measures of improvement in domestically appropriate simulators and increase of operating facilities will be drawn.

• Science of Emotion and Sensibility
• /
• v.26 no.1
• /
• pp.65-78
• /
• 2023

Aircraft are representative of human-machine systems. There is a delay between the human operation and the completion of the machine operation such as when the machine starts to operate and when the force is transmitted to the machine and completed. Time perception is an important component of timing tasks and is known to be affected by the anxiety associated with high arousal. This research verified the impact of weather, flight, and time conditions on the anxiety and time perception of in-service pilots in a virtual reality area. Weather conditions were divided into visual flight weather conditions and very low visibility conditions. Experiments 1 and 2 were performed with different flight and time conditions. In Experiment 1, time perception was measured by employing a button added to the control rod in the scenario of hovering and level flight with relatively little transformed in momentum and little delay. In Experiment 2, time perception was measured in the procedure of naturally taking off the helicopter by employing only the control stick in a takeoff scenario where there was a lot of transformation in momentum and a lot of delays. As a result of the experiment, it was reported that anxiety and heart rate increased in very low visibility conditions In particular, among all flight conditions in Experiments 1 and 2, it was reported that time was overestimated in the scenario of increased anxiety. This outcome can lead to overestimation of time under the impact of anxiety and failure of the timing task, which may lead to challenges in maneuvering and possibly lead to accidents.