Did a full blown Cat 3 replacement last night. Which means from top to bottom complete replace of the sleeving, all clamps, hardware, and string ties. Start to finish for 2 AMTs was about 12 hours with 2 good breaks (45 minute variety). This is a very labor intensive job and one that I will not do again if I have the choice. The reason for the complete rework on this one was that the sleeving previously installed had little cuts in it. I suspect this small but significant damage occurred during installation as the positioning of the bundle is behind numerous hydraulic lines and cables. Also several of the clamps had clipnuts which needed to be replaced by a simple locknut and washer arrangement. Sleeving installation has to begin at the top near the feed through at 3 inched +/- 1/2 inch of the slant panel. Our method was to completely release the bundle and pull it all out as much as we could above the cables. Install the new sleeving, begin at the top with the sting ties, to about a 1/3 point on the bundle and then pull it back down into the run, at this point the sleeving was completely string tied to a point that ended after the control cables, the next task was the most difficult, installing the ties while the bundle was behind numerous hydraulic lines. This included inserting the anti ice temp sensor wiring which enters the bundle sleeving at this point. All in all very labor intensive and difficult. Our string ties were spaced at exactly 1 inch throughout the run. Once finished with the ties behind the lines we began to install the clamping and the "snaptube". Snaptube is an additional protective device that goes over the sleeving for certain length that should extend out from the clamps holding it for 1/2 inch on either end. It is stringtied and clamped in place. We finished clamping along the top half of the run and then finished installing the sleeving at the bottom measuring it to and exact length were it ends within 1/2 inch of the connector backshell. At this time 2 ground wires had to emerge from the bundle at an exact spot between the lower clamps and should be positioned a certain way (over the bundle then down to the stud). The stud had to be installed in a certain way which we had to correct. The anti ice sensor wires had to emerge from the bundle at an exact point 12 inches from the backshell. With the sleeving completely installed and all string ties precisely installed we began clamping the lower half, all clamps have to be oriented per the paperwork with the hardware arrangement as specified, which included locknuts and washers. Clipnuts were removed from this area. Installation of the clamps was time consuming as the finished product had to result with the connector attaching to the pump in a way that didn"t have to much slack or didnt come up short. This involved releasing the lower clamps once more to get length exact then reinstalling. One clamp under a large hydraulic quick disconnect T fitting is most difficult. It sits on a ¾ inch stand off spacer and required a married clamp butterfly arrangement for the sensor wiring. BTW this was the only area were we got kicked back on the QA buyback. The paperwork didnt mention the married clamps in this area for the sensor wiring so we elected not to install it the first time. But since our sensor wires broke out of the bundle at exactly 12 inches it required a clamp there. With all clamps secured, all ties in place, all surrounding wire bundles at the top secured and tied, the connector secured and saftied, the sensor wires clamped in place and secured to the sensor an saftied. An ops check of the pump and installation of the gear door lock. We were ready for the QA buyback which is on 100% of the paperwork. With the QA buyback finished and all the paperwork completely signed an FAA buyback occurred. (With no signature requirements) We removed the gear door lock closed the door and were finished. All in all our installation was extremely clean and exact. The paperwork was vague in some areas, experience (those that had done it already) told us to rely on the figures (drawings) in the vague areas. We completed ours on a pad where it was windy and cold all through the night. Outside air temp in the 40s with a significant wind chill.
Company checkbook open on OT with some guys staying on the clock for days doing numerous airplanes. I was happy to just do one then take an AA day off to recover. This gave me the opportunity to exercise a different set of skills in an exacting nature, very satisfying yet difficult. I was told there were more the 200 completed with the remaining to be routed into DFW to be completed.