Narrative:

I was captain. We reported to the aircraft at the usual time. As is typically done; the first officer conducted the external preflight while I began cockpit checks and setup. Nothing unusual was observed on the preflight. We conducted a normal flight; where the first officer did a post flight; and we left the aircraft. I had no idea that anything was unusual until our chief pilot called me two months later. Apparently; an inspection panel on top of the wing was left unsecured by maintenance personnel during their work the night before. At some point between the time this maintenance mistake was made and two legs after we completed our flight; the unsecured panel came off and went into the engine; causing engine damage. We had no indication of anything amiss. The first officer found nothing wrong on his preflight; and we had no anomalies during flight. The first officer conducted a post flight inspection; where he found no discrepancies. Nothing was found until two additional flights were conducted by a different crew. Maintenance released the aircraft with an unsecured panel. Whatever systems and procedures our mechanics follow didn't catch the error. Any person can make mistakes; but the system should be able to catch things like this. Clearly this didn't happen. Due to the location of the panel; it is very hard to see on a normal pilot preflight. If the panel was in its normal position but not screwed in; it would be even harder to detect. I know that my first officer is very conscientious and would have done a good preflight. The takeaway from all this is a reminder to do things the proper way; and be thorough. And be prepared for anything; since many errors and discrepancies can escape even a thorough preflight.

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Original NASA ASRS Text

Title: A CRJ-900 crew reported that two upper wing service panels were missing; one of each wing; after an overnight landing gear pivot point service. The crew flew the initial flight after the service but were notified long after about the event.

Narrative: I was Captain. We reported to the aircraft at the usual time. As is typically done; the First Officer conducted the external preflight while I began cockpit checks and setup. Nothing unusual was observed on the preflight. We conducted a normal flight; where the First Officer did a post flight; and we left the aircraft. I had no idea that anything was unusual until our Chief Pilot called me two months later. Apparently; an inspection panel on top of the wing was left unsecured by Maintenance personnel during their work the night before. At some point between the time this maintenance mistake was made and two legs after we completed our flight; the unsecured panel came off and went into the engine; causing engine damage. We had no indication of anything amiss. The First Officer found nothing wrong on his preflight; and we had no anomalies during flight. The First Officer conducted a post flight inspection; where he found no discrepancies. Nothing was found until two additional flights were conducted by a different crew. Maintenance released the aircraft with an unsecured panel. Whatever systems and procedures our mechanics follow didn't catch the error. Any person can make mistakes; but the system should be able to catch things like this. Clearly this didn't happen. Due to the location of the panel; it is very hard to see on a normal pilot preflight. If the panel was in its normal position but not screwed in; it would be even harder to detect. I know that my First Officer is very conscientious and would have done a good preflight. The takeaway from all this is a reminder to do things the proper way; and be thorough. And be prepared for anything; since many errors and discrepancies can escape even a thorough preflight.

Data retrieved from NASA's ASRS site as of July 2013 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.