Topics in Category: 757 - Rotate.Aero Thu, 26 Apr 2018 15:20:39 +0000 MYOB /media/kunena/images/icons/rss.png Topics in Category: 757 - Rotate.Aero en-gb ATA 31-51, T/O Configuation Failure - by: Mark
We now had "Stabilizer" added to the list of warnings.

Wiring Diagram 31-51-41 shows the T/O Warning Configuration Module (M620) with its inputs and EICAS outputs.

Thinking this was a air/ground issue, I located K135 in the P36 panel. This relay tells the card if the aircraft is airborne or not. This relay, along with about twenty others is ultimately controlled by the nose gear squat system.

P36, forward pit, forward right side.

K135, tiny-ass relay with even tinier screws.

A relay swap did not help the issue. This pretty much ruled out the air/ground system and this topic was moved from chapter 32 to 31.

The module card is located in the P51 panel (E/E right wall).

We pulled the card (3rd from left on the bottom), nothing obvious was seen.

After reinstalling it, we ran up and put the aircraft in take-off configuation. All faults went away except the flaps. 5 degree or 10 degree flaps did not make a difference.

The flap warning could be be a secondary issue, but the original problem remains. If any item is out of configuration (brakes on for example), this warning continues to flash. This certainly is not normal and quite a nuisance when sitting in cockpit while on the ground.

This post will be updated after a replacement card is tried out.]]>
ATA 31 Indicating and Recording Wed, 25 Apr 2018 01:42:31 +0000
ATA 31-16, Master Caution Lights - by: Mark Although it is not the purpose of this site to show actual repairs, in this case the Maintenance Manual is lacking in practical steps for actually doing the job.

The mount for the light segments behind the center instrument panel seems to be permanently installed (there was no movement at all when grasping with a hand and there is no noticeable mounting hardware). Individual light assemblies (annunciator, diode block, and base) slide out of "sleeves" (6 sleeves, in this case). The annunciator and diode block come out forward. The base aft.

Some extra wires required removal from the base units of the replacement assembly. The pins came out easily with the red/white plastic tool. I used the Deutsch tool for all of them, but a Amp tool was ready for use. (Rear Release Pins)

The annunciator and diode block come out together. The are some pesky plastic pins on the diode block that take some "convincing" to slide out of the sleeve. I treated all this gingerly to start with, but it was discovered that some firmness was required to remove and install some of these (a bent pick was a great help).

The bases came out by loosening two small set screws from inside the sleeve and bending some tabs on the outside. The bent tabs could be pushed back into position with just a finger. This cannot be bypassed when installing new bases in the instrument panel sleeve (the tabs will "not" catch the raised notch on the replacement base).

Each base has a stamp "A" through "F" on the back, but the bases are physically all the same. Working with the replacement assembly on the pedestal was quite easy...... working behind the panel, not so much fun at all. The first base out was the outboard upper (or "A") "FIRE" light base.
The securing screw and base tab can be seen.

Not every base required replacement. Some of the lights just needed the annunciator/diode assembly replaced. All three of the bases that did require replacement had at least one spring loaded pin stuck down.

This job was really quite a pain in the ass. Finding the right combination of annunciators to diode blocks was frustrating. The pedestal was strewn with chunks of parts everywhere. The stuck spring pins on the bad bases could be seen from inside the sleeve, so the ones requiring replacement where identified quickly.

757-200 AMM 33-16-02]]>
ATA 31 Indicating and Recording Sat, 14 Apr 2018 02:34:56 +0000
ATA 24-22, APU Generator - by: Mark ATA 24, Electrical Power Fri, 16 Mar 2018 01:13:37 +0000 ATA 78-36, Trust Reverser Indication (P/W) - by: Mike Forti ATA 78, Engine Exhaust and Thrust Reverser Sun, 13 Nov 2016 21:18:08 +0000