hnatjstd – 第 11 页

ENG-2 N1 OVER LIMIT T

项次	内容
代码	EXC0002
信息分类	故障类
故障等级	5
事件分类	重要系统故障
实现构型	TELEDYNE
关联信息	无
信息复核	需要
复核方式	译码
复核要点	译码确认右发N1值，对比N2,FF,EGT和风向风速。
报文解读	右发N1转速超限。
标准处置建议	1，检查机上指示是否变红，读取机上超限信息；2，译码确认发动机是否存在N1超限的情况；3，自检是否存在相关故障信息；4，通过对比发动机参数匹配情况，判断是否存在指示问题。
机组操作	收油门
信息通告	通报发动机工程师。
可能性后果	发动机超限。

ENG-1 N1 OVER LIMIT T

项次	内容
代码	EXC0001
信息分类	故障类
故障等级	5
事件分类	重要系统故障
实现构型	TELEDYNE
关联信息	无
信息复核	需要
复核方式	译码
复核要点	译码确认左发N1值，对比N2,FF,EGT和风向风速。
报文解读	左发N1转速超限。
标准处置建议	1，检查机上指示是否变红，读取机上超限信息；2，译码确认发动机是否存在N1超限的情况；3，自检是否存在相关故障信息；4，通过对比发动机参数匹配情况，判断是否存在指示问题。
机组操作	收油门
信息通告	通报发动机工程师。
可能性后果	发动机超限。

CFM56-7B起动机螺栓断裂

CFM56-7B的起动机失效模式一直以来主要为滑油渗漏、解耦器断轴和轴承失效，但从2018年以来，新增了一个典型失效模式即安装螺栓断裂，对机队造成较大影响。

螺栓断裂原因厂家分析为材料承受不了剪切力而断裂，据此已采取以下相关措施：

①已改版了CMM手册，要求在起动机返厂修理时更换全套螺栓；

②已采用新的装配工艺组装起动机，会在安装时润滑螺栓以减少预应力（湿安装）；

③AMM手册已改版加入在翼更换螺栓的步骤；

④厂家推荐每1600FC对螺栓进行检查；（已在220FH间隔执行的起动机检查EO中加入详细要求）

⑤航材已下单采购足够数量的螺栓。

参考材料：

CFM56-7B发动机起动机壳体螺杆断裂探讨下载

缩短VSV作动环衬套更换后RTV胶干时间

目前CFM56-7B的VSV作动环衬套更换后使用RTV胶涂抹后，AMM手册给的胶干时间较长，并且一线不熟悉缩短胶干的方法，会造成飞机的长时间停场，经和CFM沟通协调，厂家不同意修订手册加入更多的缩短胶干时间的指导，但是邮件答复了缩短胶干时间的建议方法，具体如下。

厂家答复：

Response: To reduce the 24 hour cure time CFM recommends the following procedure:

1) Concurrent with performance of AMM task as RTV 106 is applied to bushing, apply equal thickness RTV 106 bead to tongue depressor and lay on high pressure compressor case in close proximity to installed bushing. Position quartz lamps under C-duct, directed at VSV lever arm with repaired bushing, positioned 1 to 3 feet away from replaced bushing. Ensure tongue depressor with RTV 106 is in same vicinity of repair bushing.

a) Following two (2) hours of cure, use a razor knife with tongue depressor to cut through RTV 106 at one end of the bead. If the RTV 106 is cured through to the center it will not be tacky to the touch. If the bead on tongue depressor is cured through to center of cut area, complete the repair and proceed to return aircraft to its usual condition.

b) If the bead on tongue depressor is NOT cured through to center of cut area, continue to cure aided by quartz lamps an additional 2 hours, then repeat the evaluation per (a) above.

c) Continue evaluation of the RTV 106 as noted in (a) and (b) above for up to 24 hours since RTV 106 application. After 24 hours since RTV 106 application it is permissible to complete the repair and proceed to return aircraft to its usual condition.

Note: CFM does not have additional guidance on how the variables accelerate the cure time, i.e. lamp wattage or distance. The TDS for RTV 106 (manufactured by Momentive Performance Materials) states “Higher temperatures and humidity will accelerate the cure process. Lower temperature and low humidity will slow the cure rate.” This is why a ‘test specimen’ approach is recommended.