PW1100G发动机LPT3叶片断裂风险评估与强制纠正措施决策分析

Risk Assessment and Decision Analysis of Mandatory Corrective Measure for LPT3 Blade Fracture of PW1100G Engine

针对2019年A320飞机运行中因其配装的PW1100G发动机LPT3叶片断裂频发空中停车等问题,首次采用定量风险评估、根原因分析和强制纠正措施决策的组合技术制定单边适航指令,精准解决中国机队安全监控技术难题。采用区间和比例的风险评估方法对机队风险指标和符合性时间期限分析计算;分析LPT3叶片失效机理,梳理LPT3叶片断裂根原因;提出可选纠正措施,对不同机队的风险水平决策。结果表明:南航机队风险高达1.64×10^(-8),远超过可接受的安全风险水平;起飞阶段未减推力引发机匣共振并变形,叶片材料抗撞击能力不足,导致LPT3叶片断裂;开展减推力爬升改装,并对中国机队不同风险实施不同的飞机对偶运行时间期限。为国内外机队安全监控提供了可借鉴的安全风险评估和管理方法。

In view of the frequent flight shut-down events caused by the LPT3 blade fracture of the PW1100G engine installed A320 in 2019,a combination technology was proposed based on quantitative risk assessment,root cause analysis and mandatory corrective mea⁃sures to formulate unilateral Airworthiness Directive which was accurately solved the technical problems of the safety monitoring of China fleet.The risk index and compliance time limit of each fleet were analyzed and calculated by using interval and proportion risk assessment method.The failure mechanism of LPT3 blade was analyzed,and the root cause and influencing factors of LPT3 blade fracture were sorted out.The optional corrective measures were analyzed and combined one by one,and based on the risk level decision of different fleet.The results show that the risk of China Southern Airlines fleet is as high as 1.64×10^(-8),which is far beyond the acceptable level of safety risk.During the takeoff stage,the resonance and deformation of the casing are caused by the unreduced thrust,and the anti-collision ability of the blade material is insufficient,which leads to LPT3 blade fracture.The thrust reduction climbing modification is carried out,and dual operation time periods of different aircraft are implemented for different risks of China aircraft fleet.The work provides a reference for safe⁃ty risk assessment and management method for fleet safety monitoring of domestic and foreign aircraft types in the future.