Narrative:

During climb out; a low-frequency sound and vibration was heard and felt through the airframe. The flight attendants called to report the issue at the same time the pilots were talking about it. All engine and EICAS indications were normal. Maintenance was contacted and it was determined there was not a safety of flight issue and the flight would be continued; and a write-up would be entered in the logbook. On the ground; during his initial inspection; the mechanic didn't find any open access panels. He then came to the cockpit to talk with the pilots about what they had experienced. He then performed a more detailed inspection and found a large panel on the belly of the aircraft; spanning the entire width of the aircraft (aft of the medium large transport wheel wells) was fastened on with a zip-tie and that approximately 20 (all of them) screw fasteners that were normally used to fasten the panel in place were unsecured and not flush with the panel. The pre-flighting pilot needs to be more careful in his duties; and open to recognizing anomalies for which he is not always specifically trained. In this case; I was more focused on preflighting (for the security check) the access door for the fluid reservoir located in the middle of the panel; that I didn't notice all of the popped fasteners. The aviation maintenance technician needs to ensure that the panel is re-secured when his work is complete.

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Original NASA ASRS Text

Title: A CRJ-70 Flight Crew reported a vibration noted in flight was traced to a belly panel that was improperly secured.

Narrative: During climb out; a low-frequency sound and vibration was heard and felt through the airframe. The Flight Attendants called to report the issue at the same time the pilots were talking about it. All engine and EICAS indications were normal. Maintenance was contacted and it was determined there was not a safety of flight issue and the flight would be continued; and a write-up would be entered in the logbook. On the ground; during his initial inspection; the Mechanic didn't find any open access panels. He then came to the cockpit to talk with the pilots about what they had experienced. He then performed a more detailed inspection and found a large panel on the belly of the aircraft; spanning the entire width of the aircraft (aft of the MLG wheel wells) was fastened on with a zip-tie and that approximately 20 (all of them) screw fasteners that were normally used to fasten the panel in place were unsecured and not flush with the panel. The pre-flighting pilot needs to be more careful in his duties; and open to recognizing anomalies for which he is not always specifically trained. In this case; I was more focused on preflighting (for the security check) the access door for the fluid reservoir located in the middle of the panel; that I didn't notice all of the popped fasteners. The Aviation Maintenance Technician needs to ensure that the panel is re-secured when his work is complete.

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.