2025 年 以来点火系统故障率再次高企，与2024年不同的是，点火故障部件主要集中在点火线和点火激励器，通过数据透视发现，原来的点火线和点火嘴检查工作主要集中在C检中，而2024年以后放到了A检，且检查工卡2024年依据AMM手册改版，减少了两个检查部位。导致NRC率下降到原来的20%左右。
1、修订MP项目74-020-01/02（详细检查左/右发点火导线）：增加检查点火嘴端的点火线和点火激励器输出端的检查，修订细化执行工卡以及标准，并培训一线，增加拍照反馈要求，保证执行质量。
2.同意下发MAO结合A检普查，前提是不影响暑运。航材配合保障落实，并配备到相应基地。
2025年12月，补充CFM建议
波音与CFM协调了Ref/A信息（案例#02318973），CFM提供了以下回应：
根据CFM56-7B发动机机队的经验，点火系统的故障率不存在固有的左右设计差异；两侧预计会表现相当。当操作员观察到左右不平衡时，通常是由本地因素（操作使用/任务平衡、安装/布线、环境或维护实践）驱动的，而不是固有的单侧偏差。由于操作员可以选择左侧、右侧或两侧的点火通道，如果不定期进行切换，则两侧的累计运行时间和循环次数可能会不同，这可能会造成两侧可靠性差异的假象。
此外，CFM提供了以下建议：
- 实施发动机启动时的左右点火交替，以平衡两侧的任务。
- 点火插头：在1600FC基线或在尖端损伤出现时在1000FC处进行主动主点火插头更换（SB 74-0005 Rev.1）。仅使用CFM批准的插头（CH31900-6、9072215-1或518888-1），并根据SB 74-0008选择高性能选项。
- 点火导线：在4000FC时进行详细检查（MPD 74-020-01/02；CMM 74-21-19）。检查布线、夹具、密封完整性以及是否存在放电或腐蚀现象。按照AMM 74-21-01-200-801-F00（子任务74-21-01-210-015-F00）抛光终端点蚀/烧蚀。
- 点火激励器：对于达到约10,000次循环的单元，按照CMM 74-11-12/15进行台架测试，并根据指示进行返工/更换。在适用的情况下，应用SB 74-0003筛选（按序号）。
- 保持Z尺寸在限制范围内，参考培训：myCFM门户网站->链接->培训->CTEC大学->目录->CFM->“CFM – 点火器深度浸没 – 维护分钟”。
- 使用适当的工具验证测量方法/位置；确认正确的垫片叠层。
- 在安装前将浮动燃烧室套筒对准点火器座。
- 确保清洁的安装实践；避免使用脏的或油腻的工具/手污染绝缘子/尖端。
- 对两侧进行重点机翼检查（重点关注报告的高故障率一侧），以验证导线布线和夹具的安全性、连接器扭矩/状况、电气跟踪的证据以及热/振动暴露。如有进一步支持需要，请联系波音/CFM。
Boeing coordinated the Ref /A/ message with CFM (Case # 02318973) and CFM provided the below response:
Based on CFM56-7B fleet experience, there is no inherent left/right design-driven difference in ignition system failure rates; both sides are expected to perform equivalently. When an operator observes a left/right imbalance, it is typically driven by local factors (operational usage/duty balance, installation/routing, environment, or maintenance practices) rather than an intrinsic side bias. Since the operators may select the left, right, or both ignition channels, the accumulated operating time and cycles can diverge between sides if alternation is not performed routinely, which may create the appearance of a side-to-side reliability difference.
Additionally, CFM provided below recommendations:
- Implement Left/Right ignition alternation on engine starts to balance duty between sides.
- Igniter plugs: Maintain proactive main igniter plug replacement at a 1,600 FC baseline, or 1,000 FC where tip distress has been observed (SB 74-0005 Rev.1). Use only CFM-approved plugs (CH31900-6, 9072215-1, or 518888-1), with the preferred high-performance option per SB 74-0008
- Ignition leads: Perform detailed inspections at 4,000 FC (MPD 74-020-01/02; CMM 74-21-19). Inspect routing, clamps, seal integrity, and for signs of arcing or corrosion. Polish terminal pitting/burn per AMM 74-21-01-200-801-F00 (Subtask 74-21-01-210-015-F00).
- Exciters: For units reaching ~10,000 cycles, bench test per CMM 74-11-12/15 and rework/replace as indicated. Apply SB 74-0003 screening (by S/N) where applicable.
- Keep Z-dimension within limits, refer to training: myCFM Portal -> Links -> Training -> CTEC University -> Catalog -> CFM -> “CFM – Igniter Depth Immersion – Maintenance Minute”
- Verify measurement method/location per AMM using the proper tool; confirm correct gasket stack-up
- Align the floating combustor ferrule to the igniter boss prior to installation
- Ensure clean installation practices; avoid contaminating the insulator/tip with dirty or greasy tools/hands
- Conduct focused on-wing inspections of both sides (with emphasis on the reported higher-failure side) to verify lead routing and clamp security, connector torque/condition, evidence of electrical tracking, and exposure to heat/vibration.
Contact Boeing/CFM in case further support is needed.