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作者： zeng6350

关于客运和货运的氧气压力标准差异

两者都来自于机组FCOM标准，但存在明显的差异。

客运仅依据几人制机组，什么容积的瓶体来判断是否满足。

货运则要复杂的多，会先根据100%用氧时间和人数，确定需要消耗的氧气升数；然后根据双115瓶气体量和标准温度下的压力值，查询表得出放行所需的氧气压力值（应该是就高不就低）；再根据查得的氧气压力值，来计算每5摄氏度可得到的温度补偿压力加减。

比如3人制60分钟，可查出标准用氧量为2350L；对应21摄氏度标准温度下氧气压力需要800PSI；如果当前温度为18度，则应该减去14PSI，即786PSI可以满足要求。

一号风挡管控措施

当前737NG驾驶舱1#风挡主要措施如下(注：整体管控措施在国内航司中偏严)：
1. 航线工卡：现有航后工卡(QZ-AF-02)已包含风挡无明显损伤、裂纹、过热、密封胶完好等检查；
2. A检：下发EO-73N-56-2020-002/EO-73N-56-2021-002 (T=R=550FH或800FH，注：不同客户A检间隔不一样)定期对驾驶舱各风挡及封严进行专项检查。检查内容包括划伤、缺口、裂纹、分层、跳火/电弧、气泡、封严胶破损/脱胶、潮气入侵等缺陷的详细检查。
3.C检：下发EO-73N-56-2020-001 (T=R=不超过10000FH)定期详细检查风挡玻璃整圈封严胶状况并铲除后重新封胶，避免潮气入侵；
4.改装升级：依据737-SL-30-028下发EOCOM-30-0012升级WHCU至新件号83000-27904，避免WHCU在电源转换时导致风挡过热警告。机队受影响飞机均已完成。
5.风挡软时间更换：下发EO-COM-56-2020-002/EO-COM-56-2020-001 (T=R=不超过20000FH)定期更换(注：参考国内其他航司软时限政策制定)
6.风挡保留控制：保留组/技术团队制定机队飞机保留风险等级(高、中、低风险)清单、动态更新并计划性更换，其中对于中、高风险保留的风挡不予续保的管控政策。截止今日，1号风挡有6份FC，无高风险风挡保留。
7.C检出厂飞机风挡故障处理政策：要求发现问题的风挡必须在定检中完成处理，不允许办理保留或遗留未撤除的保留放行飞机。

8. 已下发MT20-737-56-049R1关于加强737飞机一号风挡编织导线和封严检查的维护提示。

统计2021年以来的风挡更换数据，总计更换550块风挡，具体更换数据如下：

更换的风挡中，FH最高49072FH，最低4FH，平均更换时间为8912FH，具体分布如下图所示。

从每年更换风挡的平均FH来看，2024年以后数据有小幅增加。

从风挡失效的分布情况来看，数据较离散，无明显的集中失效区或渐进衰变的特征。

从风挡的故障统计情况来看，仅2021年出现1起一号风挡裂纹，后续机队未再出现裂纹的故障，整体控制较好。

关于发动机前吊架整流罩盖板封严损伤标准

SR 3-5454271361，HNA-HNA-21-0556，HNA-HNA-23-2381-10B

由于手册没有检查标准，波音当前均采用一事一议的方式。

以下案例的损伤情况，波音提供了RDR做为临时修理方案，保留100CY。（2023年后申请未得到批准）

封严：311A2535-31/311A2535-32/311A2535-33/311A2535-34

吊架整流罩盖板封严检查可以由如下项目涵盖:

1.区域检查MP70-800-01 (T=R=120CA)和70-810-02(T=R=120CA)。JC-73N-70-810/820-02

2. 航后检查工卡QZ-AF。

2023年10月补充案例

Boeing has reviewed the Ref /A/ messae and finds that the proposed time limited repair is NOT acceptable due to the location of the seals. The seal is within the fire zone of the engine per FAR 25.867 and required to be fire resistant.There are no fly on limits for continued revenue fight operations with seal section missinp or damaged. The proposed BMS 5-95 sealant is not acceptable to use in location with temperatures more than 180 degrees F (82 degrees C),Therefore the use of BMS 5-95 with speed tape wil not adequately protect the structure during a fire event.
1、Boeing recommends either the seal be replaced prior to any flight, or as a time-limited repair apply BMS 5-63 sealant to any gap with missing sealI inspect at 500 hour intervals to ensure that the sealant intact, Replace the damaged seal if further deterioration is found during repeat inspection. Boeing Recommends replacing the damaged seal at the next available opportunity, to be no later than 200 flight cles or 30 days time limit.

2、Boemg notes that BM 5-63 can have up to 72 hour cure time howeve, this can not e avoided. Beimg states that the manufacturers cure tim nstrucions for the BMS 5-63 type must be adhered too.

3、To prevent heat damage to the seal in the future and potentialy to the strut fairing panel as well, Boeing recommends checking the AMM 54-52-0 aerodnamic smoothmes recuirements at strut T/R fairing to T/R aft cowl when rigging the T/R.The allowable steps is +.0750 IN to -.1200 IN larger negative steps could result in a gap that allows hot air to vent and can cause damage to the strut faring mpanel.Reter to AMM 78-31-01/501 to adjust the T/R and increase latch pressure as reduired to correct the thrust reverser pap condition.
Our review of the guidelines provided in Boeing Service leter 737-SL-51-041 indicates this repair can be considered minor repair. Enclosed is the Ref / Repair and Devation Record RDR)form that documents acceptance of this repair data.

反推上部盖板431EL、431ER、441EL、441ER的封严受高温（约215F，封严耐450F）和高速气流的影响，在使用后出现损伤。由于SRM手册中并未给出允许损伤的标准。在经历了多次的CASE BY CASE沟通后，分别于2021年4月和2022年11月两次向波音提出机队性的放行标准申请。均被波音以需要符合FAR 25.867防火性要求，需根据每个案例的判断拒绝，建议制定合适的GVI检查间隔来发现。因此结合局方要求，编写了培训教材，并在定期工卡中加入了检查图示。后续延续运行中决策，和单起事件逐个向波音报批的政策，一些不严重的损伤会得到波音临时修复的审批。最初使用BMS5-95加金属胶带，可以作为临时措施并提供RDR。后来改为BMS5-63加金属胶带。

2023年11月更新，HNA-HNA-23-2381-10B 波音认为当损伤的间隙低于0.125英寸，是可以使用BMS 5-63来修理，可以通过加温来加速固化。并按100FC来进行目视检查，500FC完成更换。如果大于了0.125英寸需要更换。

  1. If HNA detect any gap between Pylon Strut Panel and Fairing of Thrust Reverser up to 0.125”, it may be
    repaired with BMS5-63 sealant to completely close this gap. However, if the any detected gap is higher
    than 0.125”, this seal shall be removed and, replaced by a new one.
  2. The BMS5-63 sealant has to be completely cured per BAC5000 requirements.
  3. A Detail Visual Inspection (DVI) shall be done every 100FC as stated in Ref /C/ message.
  4. This procedure is a temporary repair and, the damaged seal shall be replaced in the first opportunity and
    after 500FC per Ref /C/ message.

  1. No large gaps exceeding 0.125 inch wide are allowed in thesteady showed in Ref /C/ message and Red /D/ sketch. f any gap up to 0.125″is detected, this gap shallbe flled with BMS5-63 sealant as a temporary repaiSurface damage made by erosion etc. can be filled with BMS5-63 sealant and properly cured per BAC 5000.2. Corect. Any detected gap shall be flled with BMS5-63 sealant as temporary repair. 500 fight hours (FH) maximum.3.The ss-3 type, cs B-4has ure me f 40 hous Bmn pec BAC5-be xm) eded the ure ofM-3 seant ma be tceleratedhy sg condurcte heat with mamumt temperture of145F ts
    surface
  2. If the gap is greater than 0.125 inch, the damaged seal shabe replaced by a new one. Please note that the area is critical for fire as it is at the enaine exhaust region.5. Boeing recommends a Detail Visual inspection (DVI) at ever100 Flight Hours (FH) and replacement of the seal at a maximum of 500 Flight Hours (FH).
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