Narrative:

The problem was the way coa #8 (change order authority/authorized) bcdef, was written for aircraft abcd. The coa #8 (change order authority/authorized), bcdef, said to remove a cap from the psu (passenger service unit) assembly and discard it. But the change order authority/authorized was poorly written. The part they meant to take out, they described with the wrong nomenclature, plus there were 2 other parts on the psu with the same part numbers, but different dash numbers. The change order authority/authorized did not refer to that part with a dash number. I was the senior mechanic trying to help less qualified mechanics with the oxygen system on this particular visit for aircraft abch. The other 2 mechanics had not done this particular style of on demand oxygen system and asked me how to pack the boxes with the new style of masks. I showed them how to pack the boxes, then proceeded to work the passenger high pressure system. I also pulled temporary lead mechanic a lot during this visit. I did not sign for change order authority/authorized #8, bcdef, because the other mechanics packed the system. Air carrier X airlines discovered this non conform while aircraft abcd was in mobile, al, for work. They then realized that aircraft abch also had this change order authority/authorized done and decided to check it at the gate in chicago. They found it was non-conform and ferried it back to ZZZ. It took them 2 1/2 days in ZZZ to figure out the problem because of the poorly written change order authority/authorized. Air carrier X airlines management then also admitted that the change order authority/authorized was hard to understand and pointed out the nomenclature problem and the part number problem. Air carrier X did a self disclosure to the FAA. The end result is that if the part was left in the psu, it does not cause a safety of flight. The oxygen system still functions properly. As far as I know, air carrier X has not corrected this poorly written change order authority/authorized #8, bcdef. But, they are disciplining all mechanics involved, and myself with a level 3. And they are accusing me of blatantly disregarding the change order authority/authorized and doing things my own way. Since I did not do this change order authority/authorized, I was unaware that this part had to be removed.

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Original NASA ASRS Text

Title: A B747-400 WAS DISPATCHED IN NON COMPLIANCE WITH THE PAX EMER OXYGEN SYS CHANGED INCORRECTLY DUE TO A PUB DEFICIENCY.

Narrative: THE PROB WAS THE WAY COA #8 (CHANGE ORDER AUTH) BCDEF, WAS WRITTEN FOR ACFT ABCD. THE COA #8 (CHANGE ORDER AUTH), BCDEF, SAID TO REMOVE A CAP FROM THE PSU (PAX SVC UNIT) ASSEMBLY AND DISCARD IT. BUT THE CHANGE ORDER AUTH WAS POORLY WRITTEN. THE PART THEY MEANT TO TAKE OUT, THEY DESCRIBED WITH THE WRONG NOMENCLATURE, PLUS THERE WERE 2 OTHER PARTS ON THE PSU WITH THE SAME PART NUMBERS, BUT DIFFERENT DASH NUMBERS. THE CHANGE ORDER AUTH DID NOT REFER TO THAT PART WITH A DASH NUMBER. I WAS THE SENIOR MECH TRYING TO HELP LESS QUALIFIED MECHS WITH THE OXYGEN SYS ON THIS PARTICULAR VISIT FOR ACFT ABCH. THE OTHER 2 MECHS HAD NOT DONE THIS PARTICULAR STYLE OF ON DEMAND OXYGEN SYS AND ASKED ME HOW TO PACK THE BOXES WITH THE NEW STYLE OF MASKS. I SHOWED THEM HOW TO PACK THE BOXES, THEN PROCEEDED TO WORK THE PAX HIGH PRESSURE SYS. I ALSO PULLED TEMPORARY LEAD MECH A LOT DURING THIS VISIT. I DID NOT SIGN FOR CHANGE ORDER AUTH #8, BCDEF, BECAUSE THE OTHER MECHS PACKED THE SYS. ACR X AIRLINES DISCOVERED THIS NON CONFORM WHILE ACFT ABCD WAS IN MOBILE, AL, FOR WORK. THEY THEN REALIZED THAT ACFT ABCH ALSO HAD THIS CHANGE ORDER AUTH DONE AND DECIDED TO CHK IT AT THE GATE IN CHICAGO. THEY FOUND IT WAS NON-CONFORM AND FERRIED IT BACK TO ZZZ. IT TOOK THEM 2 1/2 DAYS IN ZZZ TO FIGURE OUT THE PROB BECAUSE OF THE POORLY WRITTEN CHANGE ORDER AUTH. ACR X AIRLINES MGMNT THEN ALSO ADMITTED THAT THE CHANGE ORDER AUTH WAS HARD TO UNDERSTAND AND POINTED OUT THE NOMENCLATURE PROB AND THE PART NUMBER PROB. ACR X DID A SELF DISCLOSURE TO THE FAA. THE END RESULT IS THAT IF THE PART WAS LEFT IN THE PSU, IT DOES NOT CAUSE A SAFETY OF FLT. THE OXYGEN SYS STILL FUNCTIONS PROPERLY. AS FAR AS I KNOW, ACR X HAS NOT CORRECTED THIS POORLY WRITTEN CHANGE ORDER AUTH #8, BCDEF. BUT, THEY ARE DISCIPLINING ALL MECHS INVOLVED, AND MYSELF WITH A LEVEL 3. AND THEY ARE ACCUSING ME OF BLATANTLY DISREGARDING THE CHANGE ORDER AUTH AND DOING THINGS MY OWN WAY. SINCE I DID NOT DO THIS CHANGE ORDER AUTH, I WAS UNAWARE THAT THIS PART HAD TO BE REMOVED.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.