ATA 78 Thrust Reversers
1 - Thrust reversers open (up) & deployed. 737-3/4/500
2 - Thrust reverser isolator wear: the answer. 737-3/4/500
3 - Thrust reverser de-activation kit. 737-3/4/500
4 - Thrust reverser synchro cable adjust procedure. Better then the AMM ! 737-ALL
5 - Thrust reverser does not operate after maintenance. Bleed it! 737-ALL UPDATED
6 - After T/R actuator change reverser light is not going off upon stowing T/R 737-3/4/500
7 - No proper reverser operation: return line fuse faulty. 737-3/4/500
8 - Thrust reverser halves are not closing even. 737-3/4/500
9 - Thrust reverser control switch spring broken. 737-6/7/8/900
10 -
Thrust reverser
stby fuse locks. 737-3/4/500
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1
- Thrust
reversers open (up) & deployed.
737-3/4/500
If a thrust reverser cowl is pumped upwards open, then it is not permitted to move it to deploy (aft) too, manual or with hydraulic power. Also the other way around, a reverser which is deployed aft, may not be pumped open (up). This is because the translating sleeve will come in contact with the fairing mounted on the pylon, as it will be damaged resulting in a removal of the sleeve for repair. A limited extension of the sleeve is possible, however, but only at the outboard reverser half with dismantled fairing. Therefore always pay attention on the position of the sleeve when working with it!
DEPLOYED...
OR up, but never both at the same time !
2 -
Thrust
reverser isolator wear: the answer.
737-3/4/500
There are no wear limits or special requirements for periodic inspection of the thrust reverser vibration isolators. The aircraft manufacturer considers it structurally and functionally acceptable to continue operating with worn thrust reverser hinge fitting vibration isolators, provided that the thrust reverser cowls can be closed and latched.
A recent review has reconfirmed that continued operation with the existing thrust reverser hinge fitting isolator configurations in a deteriorated state will not have significant adverse consequences.
See FTD 737-FTD-78-02001 for more information on this subject.
5 - Thrust reverser
does not operate after maintenance. Bleed it!
737-ALL
When a thrust reverser has been removed from the a/c, or when the hydraulic system has been opened due to a component replacement on the thrust reverser, it often happens that the reverser sleeve will not move during the first attempt. This is almost always the result of AIR, and nothing but AIR in the system. This is not stated in the AMM. The trust reverser is a "dead end" hydraulic system, which it makes it very difficult to bleed automatically. So do not replace actuators or sync-locks to quickly. Just try to bleed the system many times, by loosening the end-plug at the hydraulic lines in which the synchro-cables are running and toggling the hydraulic pump. It can make a skydroll mess on the floor, but for sure the sleeve will move again! Operate the reversers many times, allowing enough time in between. So the tip here is bleed, bleed and bleed again!
Update:
Another tip from Pat Paterson;
737 reverser will not stow after maintenance:
operate with standby pump on, this will clear the hyd lock.
6 - After T/R
actuator change reverser light is not going off upon stowing T/R.
737-3/4/500
RECTIFICATION
STEP 1 REMOVE HYDRAULIC POWER
STEP 2 REMOVE ALL SYNC SHAFTS
STEP 3 PRESSURISE HYDRAULIC
STEP 4 STOW T/R ( OBSERVED REVERSER LIGHT WENT OFF AFTER TIME DELAY AS USUAL)
STEP 5 REMOVE HYDRAULIC POWER
STEP 6 INSTALL SYNC SHAFTS
STEP 7 CARRY OUT T/R OPERATIONAL CHECK
7
- No proper
reverser operation: return line fuse
faulty.
737-3/4/500
After landing the crew moved thrust reverse levers for engine thrust reverse deployment-no proper reverse deployment,the translating sleeves are not moving at the same rate,indication of fault in the cockpit,etc. After not so fast troubleshooting fault was found:it was the RETURN LINE FUSE.(Ref.AMM 78-34-00,page 7,figure 1,AMM 78-34-07 401) Thanks to Boris from Latvia.
8
- Thrust
reverser halves are not closing even.
737-3/4/500
A heads up on this one. I had a malfunction a few nights ago on a -300 a/c #2 t/r overhead light on at push back. After many ops check good I got it this one. 1st I was going to ring out the the switches for target far and near . After unlocking the t/r and cycling it I found that the Left and Right t/r halfs on the #2 engine opening good but when stowing I found the half's to be not closing even. So this was tripping the light now It's not the iso valve but the hyd system return fuse is bad it's the one above aft heat exchanger. And make sure you have a 1 inch crow foot for the front fitting. And dont run the packs before you do this as your hand are in a tight spot hope this helps. Thanks to Nick.
9 -
Thrust reverser control
switch spring broken.
737-6/7/8/900
When you have the complaint that the thrust reverser does not extend upon selection, checkout the spring inside the control stand thrust lever handle. It is possible that the spring which operates the control switch S828 (eng#1) or S829 (eng#2) is broken. The spring can be found in the CMM 76-11-07 page 1019.
Secondly, when activation of the T/R gives you no T/R deployment and it gives you the overhead REVERSER light, checkout the adjustment of this same spring. Bad / critical or (worn) spring adjustment can give you this complaint during QUICK movement of the T/R handle (common pilot input). It then operates the switch but de-activates again with the T/R handle fully pulled rearwards (selection). With SLOW movement of the T/R handle this complaint is not there, giving you false hope. Re-adjustment of this spring is then necessary (AMM 78-34-04-700-801) , giving it a more positive input to the microswitches S828 or S829.
See pictures below for more clarification.
10 -
Thrust reverser stby fuse locks. 737-3/4/500
During standby operation test of RH thrust reversers per amm 78-31-00-735-033 REV MAY 25/2008 the reversers locked out usually around the 3rd cycle of operation.
They would no longer operate with the standby system. They would operate with
system B hydraulics.
After several minutes they would operate again using standby for two or three
cycles before locking out.
The standby pressure system fuses where tripping. The fuses where swapped per
amm 78-34-07, test failed. System B shuttle valve was replaced per amm, test
failed.
Theust reverser control valve module was replaced, test successful.
It appears that the module was allowing too much flow using the alternate system
which was tripping the fuse.
Thanks to Boudewijn d .S. for his input.