货舱门止动块损伤放行标准和更换经验

jlhuang_05 · 发表于 2021-11-17 16:09:40

最近遇到两起货舱门止动块损伤故障，手册对损伤的放行标准挺严格的，更换也没想的那么简单。

01

事件背景

737NG飞机例行检查发现货舱门止动块有缺口（或凹坑）。

前

货

舱

后

货

舱

02

放行标准

以前货舱止动块为例，查询SRM53-30-15ADL1，货舱门止动块不允许有任何损伤，放行标准还是挺严的。

再查MEL52-06A，每个舱门允许缺失一对止动装置，但限制飞50个循环。按此条操作至少可以不用趴飞机了。

03

相关航材

以此次发现的前货舱门止动块为例，更换止动块需要的航材大致如下。

止动块：143A8212-9或143A8212Y9

螺杆：BACB30MB8AK7

螺帽：BACN10YT4CD

防潮层胶带：D9100

货舱凹陷接合胶带：POLYKEN296FR

封胶：BMS5-95

注意目前IPC给的螺帽件号是错误的，手册的件号是BACN10YT8CD，直径大了一倍，波音答复十月份将修订手册。

SR3-5079676207

SUBJECT: 737NG - Wrong Part Number for Some Nuts in IPC

REFERENCES:

/A/ AIPC: 54-20-51-01 Item 53

/B/ AIPC: 53-11-00-53 Item 170

/C/ AIPC: 53-11-01-24 Item 145

/D/ AIPC: 53-11-00-17 Item 621

/E/ GUN-GUN-21-0982-01F

DESCRIPTION:

China Southern observed the wrong part number is called out for the nut in Ref/A/ to R/D/ items - the part number was indicated as BACN10YT8CD. Instead, China Southern believe the correct part number should be BACN10YT4CD.

The mating bolt for Ref/A/ to Ref/D/ is BACB30MB8AK*. According to Boeing Standard BACB30MB the nominal thread size would be 0.2500". However, the nominal thread size for BACN10YT8CD would be 0.5000 which is bigger than the thread size on mating bolt.

RESPONSE AND/OR REQUIRED ACTION:

Please kindly revise the Ref/A/ to Ref/D/ to indicate the correct part number for the nut.

RESPONSE:

Greetings:

Boeing reviewed China Southern Airlines inquiry and agrees with China Southern Airlines findings.

Boeing will revise Ref. /A/ through Ref. /D/ as requested. The subject changes will publish in China Southern Airlines 737NG AIPC on 15-OCT-2021.

Thank you for bringing this issue to our attention. Please contact us for any further assistance.

04

止动块更换

止动块由四颗高锁螺杆固定，螺杆头部是平的，需要拆货舱侧壁板接近从尾部拆卸螺杆。

高

锁