• Journal of Aerospace System Engineering
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• v.15 no.4
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• pp.30-39
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• 2021

This paper presents a study on the design and structural substantiation of the interior structure of the new VVIP aircraft. In this study, the structural design and analysis of the compartment with aluminum alloy and sandwich composite panel were performed. The structural design requirements from the Federal Aviation Administration were identified. The structural analysis of the compartment was performed by the utilization of the finite element analysis method, for the structural design process. Therefore, the designed cabin compartment secured the structural integrity, and satisfied its certification standards and design requirements via structural analysis.

• Korean journal of aerospace and environmental medicine
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• v.30 no.1
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• pp.3-17
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• 2020

The cabin environment has many physiological effects on commercial aircraft passengers and medical providers, and environmental stress factors exist. Therefore, it is important for medical providers to understand the effects of aviation physiology and cabin environment on the human body. It should also be remembered that these physiological changes and environmental stress factors can affect passengers as well as flight crew and also medical equipment. Providing medical assistance during a flight offers a number of unique challenges including lower cabin pressure, tight quarters, crowded conditions, and loud background noise. The purpose of this Korean guideline is to offer an overview on various in-flight emergencies that could be anticipated and to outline treatment priorities.

• Advances in aircraft and spacecraft science
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• v.9 no.5
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• pp.401-414
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• 2022

In the present paper, the optimal selection of batteries for an electric pump-fed hybrid rocket engine is analyzed. A two-stage Mars Ascent Vehicle, suitable for the Mars Sample Return Mission, is considered as test case. A single engine is employed in the second stage, whereas the first stage uses a cluster of two engines. The initial mass of the launcher is equal to 500 kg and the same hybrid rocket engine is considered for both stages. Ragone plot-based correlations are embedded in the optimization process in order to chose the optimal values of specific energy and specific power, which minimize the battery mass ad hoc for the optimized engine design and ascent trajectory. Results show that a payload close to 100 kg is achievable considering the current commercial battery technology.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.10
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• pp.914-923
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• 2015

UAS(Unmanned Aircraft System) has been used a lot in military applications but recently its usage is expanding to commercial applications due to its recent technical development and its market is expected to grow rapidly in the future. In hyper-connectivity society, especially UAS would play major role as an one of potential infrastructures for the architecture of the next 5G system. The ultimate goal is the successful integration of UAS in NAS(National Airspace System) relies heavily on ensuring reliable spectrum for the robust CNPC(Command and Non-Payload Communication) links as well as payload links for other various applications in the upcoming hyper-connectivity era. In this paper, we have focused on the analysis of the existing frequencies for UAS radio-control and the current issues for CNPC and payload frequencies, and proposed future efficient utilization policy for UAS in the hyper-connectivity society.

• Journal of the Korea Society for Simulation
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• v.23 no.2
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• pp.17-24
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• 2014

This study attempts to show an example of developing and applying thermal hydraulic simulation model for Aircraft-EHA. The overview of research procedure is as in the following. First, The unit hydraulic simulation model, which reflects physical quantity answering engineer's purpose is developed. Second, The unit hydraulic simulation model is combined, and then branched out to EHA hydraulic model. Third, a simulation model including flow thermal is developed, and then oil temperature rise time according to 'initial temperature and load' is examined. Finally, the master graph that can be used for designing EHA combined with thermal hydraulic analysis results in several cases is compiled, and suggested. AMESim, commercial software, is used through whole procedure.

• The Korean Journal of Air & Space Law and Policy
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• v.23 no.1
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• pp.3-32
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• 2008

In proportion to recent developments in aviation technology and growth of the air transport market, the risk of damages to third parties caused by aircrafts and the likelihood of unlawful interference on an aircraft in flight has grown larger. The war risk insurance market was paralyzed by the 9/11 terror event. And if another event on the scale of 9/11 occurs, compensations for third party damages will be impossible. Recognizing the need to modernize the existing legal framework and the absence of a globally accepted authority that deals with third party liability and compensation for catastrophic damage caused by acts of unlawful interference, the ICAO and various countries have discussed a liability and compensation system that can protect both third party victims and the aviation industry for the 7 years. In conclusion, in order to provide adequate protection for victims and the appropriate protection for air transport systems including air carriers, work on modernizing the Rome Convention should be continued and the new Convention should be finalized in the near future. Korea has not ratified the relevant international treaties, i.e. Rome Convention 1933, 1952 and 1978, and has no local laws which regulate the damage caused by aircraft to third parties on land. Consequently, it has to depend on the domestic civil tort laws. Most of the advanced countries in aviation such as the United States, England, Germany, France and even China, have incorporated the International Conventions to their national air law and governed carriers third party liability within their jurisdiction. The Ministry of Justice organized the Special Enactment Committee for Air Transport chapter under Commercial Law. The Air Transport chapter, which currently includes third party liability, is in the process of instituting new legislation. In conclusion, to settle such problems through local law, it is necessary to enact as soon as possible domestic legislation on the civil liability of the air carrier which has been connected with third party liability and aviation insurance.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.6
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• pp.532-540
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• 2008

Recently there are growing interests in calculating aerodynamic characteristics of aircraft configurations with structural deformation using the FSI(Fluid-Structure Interaction) system in which CFD(Computational Fluid Dynamics) and CSD(Computational Structure Dynamics) modules are coupled. In this paper the FSI system comprised of CAD, CFD, CSD, VSI(Volume Spline Interpolation) and grid deformation modules was constructed in order to investigate aerodynamic characteristics of the deformed shape. In the process VSI and grid generation modules are developed to combine CSD and CFD routines and to regenerate the aerodynamic grids for the deformed shape, respectively. For the CFD and CSD analysis, commercial programs FLUENT and NASTRAN were used. As a test model, DLR-F4 wing configuration was chosen and its aerodynamic characteristics were calculated by applying the static FSI system. It was shown that lift and drag coefficients of the wing at mach number 0.75 are reduced to 20.26% and 18.5%, respectively, owing to the structural deformation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.10
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• pp.687-694
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• 2019

A circular composite spar in the wing of ultra-light aircraft is subjected to both bending moment and transverse shear loads. However, the beam being used in the aircraft may be inefficient because the design would not take into account the characteristics of the circular tube that supports the bending moment in top and bottom arc parts and the transverse load in left and right ones. Therefore, it is necessary to efficiently fabricate the circular tube beam by properly selecting the stacking sequences or the laminated composite structure. In order to increase both bending and transverse shear strengths of the beams, in this study, a cross-section of circular tube is divided into four arcs: top, bottom, left and right ones. The commercial program, MSC/NASTRAN is used to calculate vertical displacement and the normal and shear strains with variation of parameters such as division angle of arc and fiber orientation. Based on the results, the effective parameters for the new circular composite beam are presented to increase its bending and shear strengths.

• 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.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.1
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• pp.67-74
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• 2022

To analyze the motion of aircraft through computing the dynamics equations, true airspeed is essential for obtaining aerodynamic loads. Although the airspeed is measured by on-board instruments such as pitot tubes, measurement data are difficult to obtain for commercial flights because they include sensitive data about the airline operations. One of the commonly available trajectory data, Automatic Dependent Surveillance-Broadcast data, provide aircraft's speed in the form of ground speed. The ground speed is a vector sum of the local wind velocity and the true airspeed. This paper present a method to estimate true airspeed by combining the trajectory, meteorological, and topology data available to the public. To integrate each data, we first matched the coordinate system and then unified the altitude reference to the mean sea level. We calculated the wind vector for all trajectory points by interpolating from the lower resolution grid of the meteorological data. Finally, we calculate the true airspeed from the ground speed and the wind vector. These processes were applied to several sample trajectories with corresponding meteorological data and the topology data, and the estimated true airspeeds are presented.