Narrative:

Aircraft xyz returned ZZZ with smoke in cabin. Secured leaking APU and performed required operation xwx. This operation is new at air carrier as of dec/xa/99. The job card refers to maintenance manual 21-20-02-2 for a duct burnout. Found maintenance manual to be very hard to follow as to which sense lines must be capped because instructions do not match illustrations. The instructions call for 2 lines to be capped, but illustrations show 3 lines to be capped. ZZZ does not allow for the APU compartment to be pressure washed on the ramp, so compartment was wiped with solvent and rags. This is allowed per job card, but all the oil cannot be removed from acoustic liner of APU inlet. In hindsight APU should have been placed on mco. Job card signoff card should have separate signoff for each job function, but several functions are included under 'perform duct burnout.' the job card instructions (step 4) say to do duct burnout per maintenance manual 21-20-02-2. The maintenance manual 21-20-02-2, item 7-C does not tell you to replace the coalescer bags. But if you read job card step 4 instructions, replacing coalescer bags and cleaning the water separators is included under 'perform duct burnout.' the job cards should have a separate signoff for coalescer bag replacement. The tooling provided by air carrier will not allow the burnout procedure to be performed as per maintenance manual. The leads and hoses for test equipment will not reach the cabin as required. Air carrier provided the kit, but did not provide any training on its use or on how to perform the test. Due to the discrepancies in the job card and maintenance manual, as well as the incomplete and vague instructions, I am not completely sure that I performed this operation xwx properly.

Related reports:

Google
 

Original NASA ASRS Text

Title: AN MD88 RETURNED TO THE FIELD DUE TO SMOKE IN THE CABIN CAUSED BY THE APU LEAKING OIL INTO THE AIR CONDITIONING DISTRIBUTION DUCTS.

Narrative: ACFT XYZ RETURNED ZZZ WITH SMOKE IN CABIN. SECURED LEAKING APU AND PERFORMED REQUIRED OP XWX. THIS OP IS NEW AT ACR AS OF DEC/XA/99. THE JOB CARD REFERS TO MAINT MANUAL 21-20-02-2 FOR A DUCT BURNOUT. FOUND MAINT MANUAL TO BE VERY HARD TO FOLLOW AS TO WHICH SENSE LINES MUST BE CAPPED BECAUSE INSTRUCTIONS DO NOT MATCH ILLUSTRATIONS. THE INSTRUCTIONS CALL FOR 2 LINES TO BE CAPPED, BUT ILLUSTRATIONS SHOW 3 LINES TO BE CAPPED. ZZZ DOES NOT ALLOW FOR THE APU COMPARTMENT TO BE PRESSURE WASHED ON THE RAMP, SO COMPARTMENT WAS WIPED WITH SOLVENT AND RAGS. THIS IS ALLOWED PER JOB CARD, BUT ALL THE OIL CANNOT BE REMOVED FROM ACOUSTIC LINER OF APU INLET. IN HINDSIGHT APU SHOULD HAVE BEEN PLACED ON MCO. JOB CARD SIGNOFF CARD SHOULD HAVE SEPARATE SIGNOFF FOR EACH JOB FUNCTION, BUT SEVERAL FUNCTIONS ARE INCLUDED UNDER 'PERFORM DUCT BURNOUT.' THE JOB CARD INSTRUCTIONS (STEP 4) SAY TO DO DUCT BURNOUT PER MAINT MANUAL 21-20-02-2. THE MAINT MANUAL 21-20-02-2, ITEM 7-C DOES NOT TELL YOU TO REPLACE THE COALESCER BAGS. BUT IF YOU READ JOB CARD STEP 4 INSTRUCTIONS, REPLACING COALESCER BAGS AND CLEANING THE WATER SEPARATORS IS INCLUDED UNDER 'PERFORM DUCT BURNOUT.' THE JOB CARDS SHOULD HAVE A SEPARATE SIGNOFF FOR COALESCER BAG REPLACEMENT. THE TOOLING PROVIDED BY ACR WILL NOT ALLOW THE BURNOUT PROC TO BE PERFORMED AS PER MAINT MANUAL. THE LEADS AND HOSES FOR TEST EQUIP WILL NOT REACH THE CABIN AS REQUIRED. ACR PROVIDED THE KIT, BUT DID NOT PROVIDE ANY TRAINING ON ITS USE OR ON HOW TO PERFORM THE TEST. DUE TO THE DISCREPANCIES IN THE JOB CARD AND MAINT MANUAL, AS WELL AS THE INCOMPLETE AND VAGUE INSTRUCTIONS, I AM NOT COMPLETELY SURE THAT I PERFORMED THIS OP XWX PROPERLY.

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.