Narrative:

I noticed that aircraft had significant and dramatic pressure bumps when closing the door and selecting packs on. The aircraft pressurized normally during all phases but the bumps were noted during any bleed configuration change. Contacted maintenance control and added to the log page as discrepancy 2. The mechanics on site came to the aircraft and began to test the pressurization in both manual and automatic modes. The pressure bumps were not as noticeable; but were still abnormal. The mechanics signed off the discrepancy as '...ops check good...no defects noted...' still concerned; I requested the mechanics check the condition of the outflow valves to make sure they were not contaminated. Upon inspection the mechanics found one of the outflow valves to be wired shut; a procedure used when deferring a component of the pressurization system. There was no current deferral regarding that system. This event occurred because a deferral was cleared improperly. This is of particular concern because it indicates that the procedure was not followed when clearing the discrepancy; and in addition; it implies that no corrective maintenance action was performed. It is a regular occurrence that components are deferred; which is a liberty that I endorse. However; when deferrals are then signed off without inspection or corrective maintenance; I am seriously concerned. There should be more oversight that mechanics are indeed following the guidance of the minimum equipment list or aircraft maintenance manual. This could be as simple as requiring mechanics to have a small checklist that they carry in their tool bags or behind their badges that guide them to the proper manuals for correcting maintenance discrepancies.

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Original NASA ASRS Text

Title: An EMB145 Captain reported during preflight finding an outflow valve improperly wired closed; apparently from an earlier cleared write up.

Narrative: I noticed that aircraft had significant and dramatic pressure bumps when closing the door and selecting packs on. The aircraft pressurized normally during all phases but the bumps were noted during any bleed configuration change. Contacted Maintenance Control and added to the Log Page as Discrepancy 2. The mechanics on site came to the aircraft and began to test the pressurization in both manual and automatic modes. The pressure bumps were not as noticeable; but were still abnormal. The mechanics signed off the discrepancy as '...ops check good...no defects noted...' Still concerned; I requested the mechanics check the condition of the outflow valves to make sure they were not contaminated. Upon inspection the mechanics found one of the outflow valves to be wired shut; a procedure used when deferring a component of the pressurization system. There was no current deferral regarding that system. This event occurred because a deferral was cleared improperly. This is of particular concern because it indicates that the procedure was not followed when clearing the discrepancy; and in addition; it implies that no corrective maintenance action was performed. It is a regular occurrence that components are deferred; which is a liberty that I endorse. However; when deferrals are then signed off without inspection or corrective maintenance; I am seriously concerned. There should be more oversight that mechanics are indeed following the guidance of the Minimum Equipment List or Aircraft Maintenance Manual. This could be as simple as requiring mechanics to have a small checklist that they carry in their tool bags or behind their badges that guide them to the proper manuals for correcting maintenance discrepancies.

Data retrieved from NASA's ASRS site as of April 2012 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.