• Title/Summary/Keyword: aviation safety

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Low-Earth orbit satellite constellation for ADS-B based in-flight aircraft tracking

  • Nguyen, Thien H.;Tsafnat, Naomi;Cetin, Ediz;Osborne, Barnaby;Dixon, Thomas F.
    • Advances in aircraft and spacecraft science
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    • v.2 no.1
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    • pp.95-108
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    • 2015
  • Automatic Dependent Surveillance Broadcast (ADS-B) is quickly being adopted by aviation safety authorities around the world as the standard for aircraft tracking. The technology provides the opportunity for live tracking of aircraft positions within range of an ADS-B receiver stations. Currently these receiver stations are bound by land and local infrastructural constraints. As such there is little to no coverage over oceans and poles, over which many commercial flights routinely travel. A low cost space based ADS-B receiving system is proposed as a constellation of small satellites. The possibility for a link between aircraft and satellite is dependent primarily on proximity. Calculating the likelihood of a link between two moving targets when considering with the non-periodic and non-uniform nature of actual aircraft flight-paths is non-trivial. This analysis of the link likelihood and the performance of the tracking ability of the satellite constellation has been carried out by a direct simulation of satellites and aircraft. Parameters defining the constellation (satellite numbers, orbit size and shape, orbit configuration) were varied between reasonable limits. The recent MH370 disappearance was simulated and potential tracking and coverage was analysed using an example constellation. The trend of more satellites at a higher altitude inclined at 60 degrees was found to be the optimal solution.

Analysis of Characteristics of CFRP Composites Exposed Under High-Temperature and High-Humidity Environment for a Long Period (고온 다습한 환경에 장기간 노출된 CFRP 복합재료의 특성 분석)

  • Hong, Suk-Woo;Ahn, Sang-Soo;Koo, Jae-Mean;Seok, Chang-Sung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.36 no.8
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    • pp.889-895
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    • 2012
  • Carbon fiber reinforced plastic (CFRP) composites have high specific stiffness and high specific strength. Therefore, they are increasingly being use, instead of conventional metallic materials in the aviation and automobile industries, where there is a strong demand for lightweight materials. In aircraft, the fuselage is exposed to severe conditions of high temperatures and high humidity. Therefore, it is necessary to estimate the strength of CFRP composites under real conditions from the viewpoint of aircraft safety. In this study, CFRP specimens were immersed in distilled water at $75^{\circ}C$ for a long time. Then, tensile tests were performed on these specimens, and the fracture characteristics of the fractured surfaces were analyzed using SEM. A fatigue test was performed on specimens immersed for 300 days with R=0.1, and it was confirmed that the fatigue life deteriorated in immersed specimens compared to specimens that were not immersed.

A Study on Systems Engineering Based Compliance Procedure for A-SMGCS (시스템 엔지니어링을 적용한 A-SMGCS 적합성 검증 방안 연구)

  • Seol, Eun-Suk;Kim, Sang-Hun;Ku, Sung-Kwan;Cho, Jeong-Hyun
    • Journal of Advanced Navigation Technology
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    • v.19 no.1
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    • pp.33-40
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    • 2015
  • Advanced surface movement guidance and control system (A-SMGCS) is a system providing routing, guidance and surveillance for the control of aircraft and vehicles in order to maintain the predetermined surface movement rate under all weather conditions while maintaining the required level of safety. In the present study, system engineering was introduced to develop the compliance procedure for the A-SMGCS. At first, requirements for the level IV A-SMGCS were defined and analyzed from the concept of operations (CONOPS). Then, system architecture and specifications were constructed through the functional analysis and allocation. After that, work breakdown structure (WBS) and related integrated master schedule (IMS) were established. Lastly, compliance checklist (CCL) and test and evaluation master plan (TEMP) were developed to verify and validate the system.

Implementation of the Traffic Control System based Low Cost Dual Modular Redundancy (저비용 이중화 시스템 기반 교통신호제어 (시스템) 구현)

  • Lee, Dong-Woo;Na, Jong-Whoa;Kim, Nam-Sun
    • Journal of Advanced Navigation Technology
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    • v.21 no.5
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    • pp.491-500
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    • 2017
  • This paper investigates a low cost dual modular redundancy system based on heartbeat which can be applied to traffic control signal system. Failure of the traffic control signal system can cause traffic confusion and traffic accidents. Therefore safety and reliability of traffic control should be secured using fault tolerance technology. To do this, we configured a redundant board using the open source hardware and the heartbeat technique of Linux HA. The function of the traffic signal control system was verified and the fault recovery time was measured using fault injection test. As a result of the test, the fault recovery time was confirmed to be less than 9 seconds on average, confirming that the reliability target time is satisfied. Based on the results of this study, it is expected that it can be applied to fields requiring high reliability systems such as aviation, space, and nuclear power embedded systems.

Scaling Methods for Icing Wind Tunnel Test (결빙 풍동시험을 위한 스케일링 기법 연구)

  • An, Young-Gab;Myong, Rho-Shin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.40 no.2
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    • pp.146-156
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    • 2012
  • In-flight icing remains as one of the most persistent hazards for aircraft operations. The effect of icing on aircraft performance and safety has to be evaluated during the development and airworthiness certification process. The scaling method is a procedure to determine the scaled test conditions in icing wind tunnels in order to produce the same result as when the reference model is exposed to the desired cloud conditions. In this study, a scaling program is developed to provide an easy-to-use tool to the aero-icing community. The Olsen and Ruff 4th methods are employed for this purpose and the velocity is calculated by matching the dimensionless Weber number. To validate the program, the results are compared with the NASA scaling results. The scaling examples based on FAR (Federal Aviation Regulation) Part 25 Appendix C are also presented. Finally, a validation study using a state-of-the-art icing simulation code FENSAP-ICE is presented.

The Economic Feasibility Analysis of a Small Size Aircraft Development for BASA Certification (항공기급 BASA 인증을 위한 소형항공기개발사업의 경제성분석)

  • Park, Jin-Woo;Hur, Hee-Young;Seo, Hae-Jong
    • Proceedings of the Korea Contents Association Conference
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    • 2008.05a
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    • pp.324-327
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    • 2008
  • This research seeks to investigate the economic feasibility of a small size aircraft development and BASA certification enterprise. To achieve the objective, this research investigates cost which requires for proceeding a small size aircraft development and BASA certification enterprise. This research also investigates the economic effects and economic benefits acquired from exporting civil aircraft. Costs and benefits are assumed using cash flow by types of airplanes. On the basis of the cash flow, this research calculates B/C ratio, NPV, IRR for investigating the economic feasibility. The result shows that there are economic feasibility for both very light jet and piston aircraft. Between these two aircraft types, more economic feasibility exist for very light jet than piston aircraft.

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A Efficient Strategy Option to Develop Public Heliport in the Metropolitan Area (수도권 공용 헬기장 발전 방안에 관한 연구)

  • Lee, Young-Jong
    • Journal of Advanced Navigation Technology
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    • v.19 no.2
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    • pp.98-102
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    • 2015
  • In this paper are This paper is about the efficient use operational management plan for the metropolitan public Jamsil heliport. First, understand the general operations and facilities to Jamsil heliport and raised the issue for them. And, in cases such as urban offshore heliport Jamsil heliport in New York and Texas (USA), for example, which was presented for comparative analysis and Jamsil heliport in London (UK). Operations, research is seen against a facility to install and manage a couple of airfield operations based on the subject by presenting the alternatives, thereby causing the principal operating facilities, infrastructure and security facilities even suggest ways to enhance the standards. Unlike other countries, Jamsil heliport location characteristics were excluded from the study on the safety aspects related to flight operations and for this I'm a military airport facilities coexist in the neighborhood.

A Study on the Allowances of Aircraft Landing Distance (항공기 착륙거리의 여유분 산정에 관한 연구)

  • Noh, Kun-Soo;Kim, Woong-Yi
    • Journal of Advanced Navigation Technology
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    • v.17 no.3
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    • pp.279-284
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    • 2013
  • Among the phases of flight operations pilots feel much pressure in landing segment. There is a number of factors affecting landing safety while pilots reduce aircraft speeds and make a touchdown and stop completely. If runway length is sufficient for landing, there maybe is no problem. But it is not the case all the time. So it is necessary to confirm whether landing performance is within limits or not. Required landing distance is actual landing distance demonstrated by flight test pilot plus allowances for average airline pilots. FAR(Federal Aviation Regulations) AFM certification is based upon manual landing for dry and wet runway. Other runway conditions are not the certification basis. JAR dictates even contaminated/slippery runway is included by prescribed allowances. Automatic landing is not certification basis, so actual landing distances are provided. In this paper I would like to analyze distance allowances included in each type of runway condition. In addition there is no regulation about allowances for specific runway condition, I would suggest adequate allowances for that case.

Analizing Korean media reports on security guard : focusing on visual analysis

  • Park, Su-Hyeon;Shin, Min-Chul;Cho, Cheol-Kyu
    • Journal of the Korea Society of Computer and Information
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    • v.24 no.11
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    • pp.195-200
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    • 2019
  • The purpose of this paper is to explore security guard's status and roles in society through media reports. Research method is to anlyze security Guard's 'Keyword Trend' and 'Keyword Frequency Analysis' by 'Big Kind' which enables 'News Big Data' analysis. The result came out by the analysis in sectional private security guard's history of settling down, growing up (quantity), and growing up (quality) by separating generations is that there are lots of attention and exposure from media about crime, security guard job, minimum wage, and 'Gabjil', but the images of security guard are recognized as victim of crime and 'Gabjil', and working in poor environment with minimum waged and ambiguous job, instead of people preventing crimes. In the future, stabilizing security guard's social status and work responsibility, and developing job professionalism are necessary to improve the images of security guard.

A Study on Development of Certification Basis for VTOL UAS Based on Analysis of Certification Criteria for Fixed/Rotary Wing UAS and SC-VTOL (고정익/회전익 인증기준 및 수직이착륙 특수기술기준 분석 기반의 수직이착륙 무인항공기 인증기준 개발 방안)

  • Yoo, Minyoung;Kim, Suho;Oh, Yeonkyeong;Jin, Kyunghoon;Lee, Hwan;Kim, Woogyeom;Gong, Byeongho
    • Journal of Aerospace System Engineering
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    • v.15 no.5
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    • pp.16-23
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    • 2021
  • Domestic and foreign manufacturers are developing VTOL UASs in various shapes in line with demand for future technologies. UASs have been developed in a shape classified as fixed/rotary wing, and verified by appropriate certification standards. However, airworthiness certification of recent VTOL UASs is strict with the absence of VTOL-specific certification standards. In this paper, criteria applicable to VTOL UAS were presented through analysis of STANAG-4671 and STANAG-4702, which are certification standards for fixed/rotary wing UAS of the North Atlantic Treaty Organization (NATO) and the Special Condition for VTOL Aircraft (SC-VTOL) of European Aviation Safety Agency (EASA). For this, the categorization criteria of general/fixed-wing/VTOL characteristics were established for each standard item and utilized for analysis.