Narrative:

I was assigned to work on air carrier aircraft X, an L1011. The aircraft had an inbound write-up on cabin pressurization. I was familiar with this aircraft and its extensive cabin pressurization history as I had worked it on a previous occasion. The aircraft also had its forward outflow valve on maintenance carryover in accordance with the MEL. After checking the system out, I determined the forward outflow valve actuator to be at fault. I replaced the actuator and, after the appropriate chkout, I signed the item off and released it for service. However, the inbound write-up also addressed improper operation of the cabin altitude warning system. Since I was familiar with the history and was eager to fix the pressurization problem, I failed to fully read and comprehend the significance of the cabin altitude warning system discrepancy and I did nothing to address that aspect of the write-up. The aircraft was dispatched and flew with no discrepancy. The following day, a late night shift lead technician brought this all to my attention. I immediately notified the maintenance coordinator center of my error and had them put a set-up in the operational maintenance instructions to have the cabin altitude warning system checked out.

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Original NASA ASRS Text

Title: AN L1011 WAS DISPATCHED IN NON COMPLIANCE WITH AN OPEN LOGBOOK RPT ON THE CABIN ALT WARNING SYS INADVERTENTLY OVERLOOKED.

Narrative: I WAS ASSIGNED TO WORK ON ACR ACFT X, AN L1011. THE ACFT HAD AN INBOUND WRITE-UP ON CABIN PRESSURIZATION. I WAS FAMILIAR WITH THIS ACFT AND ITS EXTENSIVE CABIN PRESSURIZATION HISTORY AS I HAD WORKED IT ON A PREVIOUS OCCASION. THE ACFT ALSO HAD ITS FORWARD OUTFLOW VALVE ON MAINT CARRYOVER IN ACCORDANCE WITH THE MEL. AFTER CHKING THE SYS OUT, I DETERMINED THE FORWARD OUTFLOW VALVE ACTUATOR TO BE AT FAULT. I REPLACED THE ACTUATOR AND, AFTER THE APPROPRIATE CHKOUT, I SIGNED THE ITEM OFF AND RELEASED IT FOR SVC. HOWEVER, THE INBOUND WRITE-UP ALSO ADDRESSED IMPROPER OP OF THE CABIN ALT WARNING SYS. SINCE I WAS FAMILIAR WITH THE HISTORY AND WAS EAGER TO FIX THE PRESSURIZATION PROB, I FAILED TO FULLY READ AND COMPREHEND THE SIGNIFICANCE OF THE CABIN ALT WARNING SYS DISCREPANCY AND I DID NOTHING TO ADDRESS THAT ASPECT OF THE WRITE-UP. THE ACFT WAS DISPATCHED AND FLEW WITH NO DISCREPANCY. THE FOLLOWING DAY, A LATE NIGHT SHIFT LEAD TECHNICIAN BROUGHT THIS ALL TO MY ATTN. I IMMEDIATELY NOTIFIED THE MAINT COORDINATOR CTR OF MY ERROR AND HAD THEM PUT A SET-UP IN THE OPERATIONAL MAINT INSTRUCTIONS TO HAVE THE CABIN ALT WARNING SYS CHKED OUT.

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.