• Title, Summary, Keyword: Tail Strike

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A Study on B737NG Aircraft Tail Strike during Takeoff (B737NG 항공기 이륙 중 미부지면접촉에 관한 연구)

  • Noh, Kun-Soo
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.17 no.4
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    • pp.70-75
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    • 2009
  • According to the aviation statistics, tail strike incidents and accidents are cyclic. Although many tail strikes occurred during takeoff, these are less than during landing cases. Many cases are related on human factors. In my opinion it is possible to analyze the causes of takeoff tail strikes to some extent. There are major casual factors of tail strike during takeoff such as; (1) Mis-trimmed horizontal stabilizer (2) premature rotation prior to $V_R$ (3) Excessive pitch up rate during rotation (4) Improper use of the flight director. Among these causes improper use of flight director is excluded in this paper because it is recommended that pilot should use flight director after airborne. So I analyzed the other three causes as following. Firstly, because mis-trimmed stabilizer is related to center of gravity(CG), the relationship between stabilizer and CG is reviewed. Secondly, concerned premature rotation prior to $V_R$ I reviewed the background of rotation speed($V_R$) establishment and analyzed theoretically what speed leads to tail strikes. Thirdly, concerning excessive pitch up rate during rotation I analyzed what excessive pitch up rate can decrease ground clearance while using FDR data.

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Study on Evaluation of Structural Integrity for Small Aircraft Tail (소형 항공기 미익부 구조 건전성 평가에 관한 연구)

  • Lee, Muhyoung;Park, Illkyung;Kim, Sungjoon;Ahn, Sukmin
    • Journal of Aerospace System Engineering
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    • v.6 no.2
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    • pp.28-34
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    • 2012
  • Structural integrity evaluation is important item in the aircraft certification. Recently, it is designed for limit load, material weakness about fatigue and corrosion, damage by bird strike in flight to evaluate structural integrity of aircraft. And static/fatigue analysis are performed to secure structural integrity, it was verified by static and fatigue tests. To evaluate the structural integrity of small aircraft tail, structural integrity was calculated by the finite element analysis. In the present study, finite element analysis are performed to pick out load cases in flight occurrence, and secure margin of safety to evaluate structural integrity of KC-100 tail unit. The proprieties of finite element analysis results are compared with the static structure test results. The estimation process of structural integrity for small aircraft tail may help the design.