反推系统的排故提示的分析

小丛

一、总述：

BOEING收到许多用户对于B737 NG飞机反推系统故障的报告，主要有以下几种原因造成了反推系统可靠性的下降：

- 自动油门电门组件的电门调节问题

- 隔离活门传感器(S833, S830)故障

- 飞行员收回反推的操作程序

- 传感器接头线路问题

 

二、系统分析：

（1）自动油门电门组件的电门调节问题

故障现象：

反推无法收回或放出，多数情况下P5板的RESERVER灯会点亮，并且EAU上某些故障灯会点亮。

BOEING的研究发现，大多数情况下这些异常现象是由于自动油门电门组件(AIPC 22-31-51-01 Item 205)的电门失去调节引起的。自动油门电门组件中的电门S4，S5和S6 (AIPC 78-34-04-01 Item 35, 78-34-04-01 Item 37)控制反推系统的工作。由于通常情况下这些故障的发生是瞬时性的，从而给排故带来困难。

自动油门电门组件给飞机系统提供油门杆位置信号。自动油门电门组件包括9个电门，周向分布在一个凸轮组(共三个凸轮)上，每个凸轮上包含3个电门，由油门杆作动。油门杆的移动通过机械连接带动凸轮运动，凸轮的高、低位通过凸轮的运动作动电门。这些电门用于：速度刹车、起落架警告、前缘地面防冰、起飞警告、气象雷达、自动刹车、反推同步锁、反推预位、反推收回。

由于现有设计的电门作动距离太小，导致电门的调节比较困难。BOEING重新设计了改进的电门组件，增加了作动距离，从而保证了电门作动的可靠性。在线号200及以后的B737 NG飞机已经采用了新的电门组件(P/N 254A1150-9 and P/N 254A1150-10 for the left and right sides)。

 

NOTE: 深航B2633、B2635飞机线号分别为110、127，多次反映有反推灯亮的故障，更换的EAU在厂家测试无故障，相信应该是自动油门电门组件的电门调节问题引起的。技术室曾下发MT737-78-0001，描述了该问题以及建议措施。

 

AMM78-34

You can deploy the thrust reversers when the airplane is less than 10 feet (3 meters)from the ground.The flight control computers (FCC)and a radio altimeter operated relay supply airplane altitude information.An air sensing relay supplies the air/ground logic.The fire handle must be down for the control system to use the electrical power.

Each T/R control valve module controls hydraulic power to deploy or stow their T/R.Each module contains the electrical and hydraulic components necessary to control the hydraulic

flow to the T/R hydraulic actuators.There are two T/R control valve modules on the airplane.One for each T/R.

Sync shafts on each translating sleeve make sure the sleeve ’s three actuators operate at the same speed.The actuators can operate only if the shaft is free to turn.

A sync lock connects to the bottom hydraulic actuator on each T/R half.The sync lock must unlock for the sync shafts to turn.

During normal T/R operation,the sync locks energize to unlock.The sync lock is also a manual drive mechanism.You use the sync lock to manually move the T/R translating sleeves for

maintenance operations.

 

The reverser thrust levers operate switches on the autothrottleswitch packs.These switches control signals to thesecomponents:

*EAU —— S6 Stow Switch

*Sync locks —— S4 Sync locks Switch

*Control valve module. —— S5  T/R Arm Switch

 

The arm and stow switches control the arm and deploy signals to the T/R control system.The system uses these signals to control hydraulic power to the T/R.

The sync lock switches control power to the circuits which control sync lock power.

SSM78-31-00

SSM78-32-51

SSM78-34-11

（2）隔离活门传感器(S833, S830)故障

故障现象：

在执行反推系统维护工作时，反推在放出状态，液压泵在OFF位，P-5面板的REVERSER灯点亮，同时EAU上HYD ISO VALVE SENSOR灯点亮。

在地面使用液压释放反推，然后断开液压（将液压泵电门放到OFF位）执行维护工作时，P-5面板的REVERSER灯点亮，同时EAU上出现HYD ISO VALVE SENSOR故障信息，这种指示对于反推系统而言是正常的。反推系统控制活门组件中的液压隔离活门通过弹簧加载在关闭位，如果没有T/R系统故障，当反推不在收回位并且控制系统具备28V直流电时，预位电磁活门提供液压去打开液压隔离活门。在将液压泵电门放到OFF时，没有液压使液压隔离活门保持在开位，因此由于弹簧力的作用活门将关闭。液压隔离活门的位置传感器感受到活门在关闭位置而反推手柄在释放位，由此触发了HYD ISO VALVE SENSOR故障，而导致P-5面板的REVERSER灯点亮。

 

NOTE: 在完成了维护工作后，可以通过提供液压多次收放反推来重置故障，或者在反推释放状态下提供液压到反推系统，同时按压EAU上的RESET按钮至少2秒钟，然后依照MM78-31-00/201收回反推。技术室曾下发M737-78-0101描述了该问题。

Each T/R control valve module has these internal components:

*Isolation valve

*Directional control valve

*Isolation valve proximity sensor

*Directional control valve proximity sensor

*Arm solenoid

*Stow solenoid

*Deploy solenoid

*Manual isolation (shutoff)valve.

The manual isolation valve handle has a hole for the T/R maintenance deactivation pin.

 

Training Information Point

You use the manual isolation valve handle to prevent accidental operation of T/Rs when persons or equipment are near the T/R.

You put in a lock pin to keep the handle in the shutoff position.

The T/R deactivation for maintenance is different than the T/R deactivation for airplane dispatch.Be sure to follow the airplane maintenance manual (AMM)procedures.

WARNING:

BEFORE YOU REMOVE THE LOCK PIN FROM THE T/R CONTROL VALVE MODULE FOR THE THRUST REVERSER,MAKE SURE THE THRUST REVERSER

SLEEVES ARE IN THE CORRECT POSITION.

IF THE THRUST REVERSER SLEEVES ARE IN THE STOWED POSITION,THE REVERSE THRUST LEVER MUST BE FULLY FORWARD.

IF THE THRUST REVERSER SLEEVES ARE IN THE DEPLOYED POSITION,THE REVERSE THRUST LEVER MUST NOT BE IN THE STOWED POSITION.

IF THE POSITION OF THE REVERSE THRUST LEVER DOES NOT AGREE WITH THE POSITION OF THE THRUST REVERSER SLEEVES, THE THRUST REVERSER SLEEVES COULD MOVE WHEN THE HYDRAULIC SYSTEM IS ACTIVATED.

THIS COULD CAUSE INJURY TO PERSONS AND DAMAGE TO EQUIPMENT.

 

 

（3）飞行员收回反推的操作程序

故障现象：飞机降落打开反推后无法收回或者反推故障灯点亮，反推手柄在反推慢车位和收回位之间。

以下描述了当反推手柄在某个特殊位置的情况：

-         如果反推手柄在从反推慢车位向收回位两个球的位置时，将激励EAU的BITE检查反推是否在8秒钟内收回。

-         如果反推手柄再向前一个球(从反推慢车位向收回位三个球)，EEC的BITE检查不使用前推力，直到反推完全收回(10秒延时器)。

-         如果反推手柄位于从反推慢车位向前四个球的位置，反推将收回。

如果反推手柄在从反推慢车位向前两个球到三个球的区间停留时间较长，上述的一个或以上的BITE将不能通过，从而导致EAU或EEC的故障指示。如果反推手柄在该区间提留超过16秒，同步锁将锁定，反推将停留在原位直到反推手柄通过循环复位。

如果ENG CONTROL灯点亮，必须检查FMC-CDU EEC当前故障，确认属于ENGINE CONTROL LIGHT级别的故障代码只有78-31521 (engine No. 1)和78-31522 (engine No. 2)。另外，如果EEC的通道交换数据链不工作，以下的故障代码可能以任意的组合方式出现：

78-11521 (ENG 1)                  78-11522 (ENG 2)

78-21521 (ENG 1)                  78-21522 (ENG 2)

73-10101 (ENG 1)                  73-20102 (ENG 2)

如果确认了只有以上的EEC故障代码出现，可以通过多次收放来重置反推故障灯。

 

NOTE: 为避免出现以上故障出现，反推手柄应该避免停留在反推慢车位和收回位之间，。通常情况下，从反推慢车位置到收回位置(或反向)的运动不应该超过3秒钟。BOEING曾经颁发Flight Operation Technical Bulletin 99-3 描述了该问题。

 

EAU的功能

The engine accessory unit (EAU)has these functions:

*Controls the thrust reverser (T/R)auto-restow operation

*Helps you do trouble-shooting of the T/R control system

*Controls the REVERSER lights on the P5 aft overhead panel in the flight compartment.

 

 

反推灯亮的几个条件

A REVERSER light comes on when any of these conditions happen:

*For 10.5 seconds after T/R stow command

*T/R stow control system component fault (except during a deploy operation)

*T/R deploy control system component fault during deploy operation.

The engine accessory unit (EAU)contains the logic necessary to identify T/R control system component faults.The EAU controls the REVERSER lights.

Stow Fault Logic

The EAU identifies any of these conditions as a stow fault:

*Any sleeve stow sensor is near (10s after stow command)

*Any sleeve lock sensor is near (10s after stow command)

*Left or right sync lock voltage (26s after stow command)

*Directional control valve (DCV)sensor near (15s after stow command)

*HIV sensor near (15s after stow command).

For any of these conditions the REVERSER light comes on.The light goes out when the stow fault goes away.The master caution and the ENG annunciator come on if the fault stays for

more than 13 seconds.

The REVERSER light will come on and stay on (latch)if the EAU sees the arm switch fail to the deploy position.This is the only stow fault that keeps the REVERSER light on.You must replace the switch,deploy the T/R and reset the EAU to make the REVERSER light go out.

 

Deploy Fault Logic

The EAU identifies any of these conditions as a deploy fault:

*Any sleeve stow sensor far (6s after deploy command)

*Any sleeve lock sensor far (6s after deploy command)

*No left or right sync lock voltage (2s after deploy command)

*Directional control valve (DCV)sensor far (6s after deploy command)

*HIV sensor far (6s after deploy command).

For any of these conditions the REVERSER light comes on.The master caution and the ENG annunciator comes on if the fault stays for more than 13 seconds.

 

A deploy fault keeps the reverser light on.You must fix the problem which causes the fault,deploy the T/R,and clear (reset)the EAU deploy fault memory before the reverser light

can go out.

 

（4）传感器接头线路问题

故障现象：

飞行中REVERSER灯点亮，通常以下之一的EAU故障灯也点亮：

S831 L SLEEVE STOWSENSOR

S835 L SLEEVE LOCK SENSOR

S832 R SLEEVE STOWSENSOR

S836 R SLEEVE LOCK SENSOR

S833 HYD ISO VALVE SENSOR

S833 HYD ISO VALVE SENSOR 点亮是由于以上四个故障之一激励了反推自动收回系统。

由于以下机体-机翼、吊架-机翼间的过渡电接头的瞬间问题导致了此故障：

NOTE: 这些电接头位于机体-机翼、吊架-机翼的结合面，通常是因为接头的污染引起的。通常检查、分离后重新安装可以解决问题。某些情况下，电接头可能需要更换。

 

小结

当发现反推系统的故障时，需要详细的描述以充分了解现象和帮助排故。这对于反推系统特别重要，因为反推系统的故障非常多样化。然后按照FIM的指导结合以上的信息来排故。

另外很重要的一点，EAU的故障代码对排故也是很关键的。EAU的故障代码可以通过5次收放反推来清除，但是这仅仅清除了故障代码，并没有排除故障，故障可能在下一个航段后又会出现。

zhl701301

好东东，可惜跟我遇到的问题还是有差别。

liming3321

高人倍出啊！

壮壮0219

高人倍出啊！

新手

谢谢啊，正找这些呢！！！

英雄一代

是个精华贴啊，谢谢了

bluejean

貌似这是深航的一个很老的备忘录，不过在总结总结很实用

旭日东升

分析的挺好的。

630668

不错 不

basket

多谢了！！！

仁义道德

高手！有一群默默无闻的人，埋头工作，确保飞机正常。谢谢你的分享！

zhuzhuysf

不错不错

poretyoung

谢谢，看看反推。

stsg666

楼主分析的很全面···

dongdongzj

收藏了，感谢楼主

xpk1987

中英结合一举两得啊

行客人间

EAU故障多发呀！

机务张SIR

介绍的非常详细！学习中！

henanzz111

有时间得好好研究一下

gdwdaviy

没下细看！  貌似不错哈！为得点GB ！下次好好看！