• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.47 no.7
• /
• pp.525-534
• /
• 2019

Water rocket is a pressurized liquid propellant rocket that shares the same basic principles of space launch vehicles. Water rockets can be used as an engineering educational material for the liquid rocket principles and the launch vehicle systems, far beyond the scope of K-12 level science education. In this paper, the principles and theories of water rocket propulsion and flight dynamics was investigated at the level of undergraduate rocket engineering classes. Also, the system level design and operation of water rocket is summarized by including the components of launch vehicle, launch pad, payload and recovery as well as altitude measurement methods.

• Journal of Advanced Navigation Technology
• /
• v.27 no.6
• /
• pp.746-754
• /
• 2023

Aircraft accidents are characterized by a low probability of survival compared to other means of transportation, and the main causes appear to be human factors such as violation of regulations and communication. In order to activate the safety management system to prevent such accidents, an important key variable is to recognize the importance of safety culture and actively engage in safety behavior rather than simply emphasizing compliance with regulations to flight crew members. Even if there are well-established regulations, safety culture, The effectiveness varies depending on the safety atmosphere and level of safety behavior. In this study, the correlation between safety culture and safety behavior was verified through a survey of domestic flight crew members' awareness of safety culture. The results showed that fair culture and self-reporting were not activated enough to have a significant impact on safety behavior. We aim to improve the performance of the safety management system by confirming the characteristics of safety culture and safety behavior.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.28 no.4
• /
• pp.164-170
• /
• 2020

Recently, the aviation industry faced a major crisis due to the impact of COVID-19. However, despite the sluggish passenger transportation, the cargo transportation sector is relatively maintained or increasing depending on the item. In this study, we will look at the trends before and after COVID-19, focusing on the cargo export field, which is a concern of the aviation industry. First, it analyzes the entire air cargo and then analyzes the trends of each item and country in detail. In particular, it examines the process of changes in air transport costs, which increased significantly immediately after COVID-19, and conducts future trends and prospects in the cargo export field. As a result of the study, some characteristics of air cargo exports before and after COVID-19 were found in an analysis by item and country, and transportation costs varied according to route distance.

• Journal of Advanced Navigation Technology
• /
• v.24 no.6
• /
• pp.515-520
• /
• 2020

The development of autopilot system and flight management system (FMS) equipment in today's aircraft navigation can be attributed to the reduction of pilots' workload and the navigation safety. The effect of autopilot and FMS equipment is greater, especially in heavy airport traffic or complicated of the departure. However, some airport specific departure procedures result in an uncommanded turn event due to an error in the FMS, causing aircraft to deviate from the center line of the route. With most departure procedures requiring area navigation (RNAV) operation, pilot situation awareness and corrective action are the only ways to minimize aircraft deviation to maintain the safety of area navigation. Through analysis of the occurrence status of the uncommended turn event by aircraft type, airport and flight phase, and comparative analysis of the survey results of foreign airlines and the airlines self-reduction plan with the aircraft manufacturer's corrective action, it is intended to give implications for the need for more fundamental measures to prevent recurrence of such events.

• Journal of Advanced Navigation Technology
• /
• v.25 no.1
• /
• pp.52-59
• /
• 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 Advanced Navigation Technology
• /
• v.25 no.3
• /
• pp.248-255
• /
• 2021

The main causes of the July 2013 OZ 214 accident were poorly performed approach and the failure to recognize the autothrottle in the HOLD position which the automated speed control was not provided. The pilots late decision for go-around was also a critical factor leading to the accident. The B777 POM restricts the use of FLCH mode beyond the FAF. This research utilized the QAR data of an airline's B777 fleet in the period of two years where 44 cases were found. In many cases, the FLCH mode was used for rapid descent from an higher than normal situation. In addition, in the base turn, continuous use of FLCH mode even when the path was below the glide path were observed. Airports with elevation above 500 ft MSL had a higher rate of occurrence. In this research, the proper descent planning and vertical path monitoring, and the adherence to the limitation set in the manuals and the stabilized approach criteria were re-emphasized as mitigation to reduce event occurences.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.43 no.9
• /
• pp.765-772
• /
• 2015

Aerodynamic force measurements and phase-locked PIV study were carried out to check the bio-mimetic MAV applicability of a swift flight. Two-rotational DOF robotic wing model and blowing-type wind tunnel were employed. The amplitude of twist angle were ${\pm}0$, ${\pm}5$, ${\pm}10$, and ${\pm}20$ deg. and stroke angles were manipulated by simple harmonic function with out-of-phase in regards to the stroke motion. It is acknowledged that the time-varying lift coefficients in accordance with the change of the twist angle did not result in any noticeable differences, just the small decrease and delay. However, the drag exhibited that the small change of the twist angle can produce large thrust. These findings imply why a swift uses small twist angle during flight. The PIV results displayed that the delay of aerodynamic forces is highly associated with the vortical structures around the wing. It is therefore indicated that a process of designing a swift-based Micro Air Vehicle should take the twist angle into consideration, as the essential parameter.

• Journal of Advanced Navigation Technology
• /
• v.20 no.4
• /
• pp.292-297
• /
• 2016

Since continuous descent operations (CDO) is one of several tools available to aircraft operators and air navigation service providers (ANSPs) to increase safety, flight predictability, and airspace capacity while reducing noise, controller-pilot communications, fuel burn and emissions, widespread implementation of CDO would result in significant reductions in the environmental impact and aircraft operation costs in south korea as well. After analyzing each procedure from standard terminal arrival routes used for the Incheon international airport, it can be noticed that one of the procedures has a relatively high altitude constraint at initial approach fix than others, which lead the pilots to use unnecessary drag device in certain situations. Therefore we came to a conclusion that some arrival procedures need to be revised, so unnecessary procedure required during approach can be minimized, thereby reducing fuel consumption, noise and emissions compared to current approach procedures. And it is going to increase the safety margin significantly during approach phase due to reduced workload.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.29 no.2
• /
• pp.106-110
• /
• 2021

In this study, the main factors affecting the number of passengers and cargo volume transported by air between Korea, China and Japan over the past 20 years are to be identified. For the analysis, data from three countries' GDP and per capita as well as exchange rates and international oil prices were used, and OLS multiple regression analysis and fixed effect analysis were performed. As a result of the analysis, both the number of passengers and cargo volume transported by air showed a negative (-) direction for GDP, which represents the country's economic power, and a positive (+) direction, for per capita GDP, which represents income level. And the increase in the exchange rate between China and Japan acted in a positive (+) direction on the increase in the number of passengers, and the effect of oil prices was found to be limited.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.29 no.3
• /
• pp.111-116
• /
• 2021

This study aims to identify the representative factors affecting the air trade between the two countries over the past 20 years, targeting China, Korea's largest trading partner for air transport. In the analysis, the two countries' GDP, GDP per capita, and tariff rates, as well as exchange rates, international oil prices, and FTAs were used as variables. For the analysis method, OLS multiple regression analysis was performed, and each was analyzed by dividing the export amount, import amount, and trade amount. As a result of the analysis, China's GDP and Korea's GDP per capita showed a positive (+) direction, an increase in the exchange rate resulted in an increase in the amount of trade, and an increase in the tariff rate resulted in a decrease in the amount of trade. Whether the FTA was concluded or not acted as a factor in increasing the amount of trade between the two countries.