Narrative:

Aircraft was operated for 3 days in revenue service with improper informational placards and instrument installed in cockpit, with related performance penalty, due to failure of company maintenance personnel to perform an internal maintenance document (engineering order) while aircraft was down for a scheduled maintenance and inspection check. The problem was discovered by pilot while taxiing out for takeoff, when comparing flight dispatch information with ram air temperature indicator in cockpit. Things went downhill from there. Aircraft had an engine intermix confign (JT8D-9A on l-hand side, and JT8D-7B on r-hand side), prior to problem. Due to a slight power output reduction of the -7B engine, this intermix, through the accomplishment of an engineering order, mandated that the aircraft be operated at -7B power settings for EPR readings, and a 2000 pound performance penalty in maximum takeoff gross weight of the aircraft, from 110000 pounds to 108000 pounds. R-hand engine was subsequently changed, with an identical JT8D-9A now installed, to match the left side. However, an accompanying engineering order to reverse the previous engineering order procedures for the intermixed confign was not done, due to a paperwork snafu. Consequently, the aircraft was now operating under a performance penalty in terms of engine EPR power reductions and maximum takeoff weight reductions, though both pwrplants were matched with JT8D-9A power. When the error was discovered, the relevant engineering order for de-intermixing engines was then accomplished, with associated weight and balance recalculation done the following day. Confusing paperwork procedures was a big factor at the heart of the problem, with poor judgement and outdated work cards for the task contributing factors, and poor internal communication. The aircraft did not experience an incident.

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Original NASA ASRS Text

Title: A DC9-30 WAS DISPATCHED AND OPERATED IN NON COMPLIANCE WITH INTERMIX ENG PERFORMANCE AND WT REDUCTION LIMITS IN ERROR.

Narrative: ACFT WAS OPERATED FOR 3 DAYS IN REVENUE SVC WITH IMPROPER INFORMATIONAL PLACARDS AND INST INSTALLED IN COCKPIT, WITH RELATED PERFORMANCE PENALTY, DUE TO FAILURE OF COMPANY MAINT PERSONNEL TO PERFORM AN INTERNAL MAINT DOCUMENT (ENGINEERING ORDER) WHILE ACFT WAS DOWN FOR A SCHEDULED MAINT AND INSPECTION CHK. THE PROB WAS DISCOVERED BY PLT WHILE TAXIING OUT FOR TKOF, WHEN COMPARING FLT DISPATCH INFO WITH RAM AIR TEMP INDICATOR IN COCKPIT. THINGS WENT DOWNHILL FROM THERE. ACFT HAD AN ENG INTERMIX CONFIGN (JT8D-9A ON L-HAND SIDE, AND JT8D-7B ON R-HAND SIDE), PRIOR TO PROB. DUE TO A SLIGHT PWR OUTPUT REDUCTION OF THE -7B ENG, THIS INTERMIX, THROUGH THE ACCOMPLISHMENT OF AN ENGINEERING ORDER, MANDATED THAT THE ACFT BE OPERATED AT -7B PWR SETTINGS FOR EPR READINGS, AND A 2000 LB PERFORMANCE PENALTY IN MAX TKOF GROSS WT OF THE ACFT, FROM 110000 LBS TO 108000 LBS. R-HAND ENG WAS SUBSEQUENTLY CHANGED, WITH AN IDENTICAL JT8D-9A NOW INSTALLED, TO MATCH THE L SIDE. HOWEVER, AN ACCOMPANYING ENGINEERING ORDER TO REVERSE THE PREVIOUS ENGINEERING ORDER PROCS FOR THE INTERMIXED CONFIGN WAS NOT DONE, DUE TO A PAPERWORK SNAFU. CONSEQUENTLY, THE ACFT WAS NOW OPERATING UNDER A PERFORMANCE PENALTY IN TERMS OF ENG EPR PWR REDUCTIONS AND MAX TKOF WT REDUCTIONS, THOUGH BOTH PWRPLANTS WERE MATCHED WITH JT8D-9A PWR. WHEN THE ERROR WAS DISCOVERED, THE RELEVANT ENGINEERING ORDER FOR DE-INTERMIXING ENGS WAS THEN ACCOMPLISHED, WITH ASSOCIATED WT AND BAL RECALCULATION DONE THE FOLLOWING DAY. CONFUSING PAPERWORK PROCS WAS A BIG FACTOR AT THE HEART OF THE PROB, WITH POOR JUDGEMENT AND OUTDATED WORK CARDS FOR THE TASK CONTRIBUTING FACTORS, AND POOR INTERNAL COM. THE ACFT DID NOT EXPERIENCE AN INCIDENT.

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.