A crj-200 first officer reported airframe vibration in flight. Upon arrival the left engine jetpipe ...

Narrative:

During my preflight walk-around; no defects were noted with the aircraft. All exterior hatches; doors; and latches were secured or in their expected state. On descent; when I brought the thrust levers back to idle; we experienced a short airframe vibration (approximately 1 second). When we leveled and thrust was at a mid-to-low range; we felt a significant airframe vibration. The left engine fan vibration gauge fluctuated between 2.3 and 2.8; and the left engine oil temperature was significantly lower than the right. During further descent I elected to leave the left engine at idle while we investigated. The vibration did not return for the remaining 5 minutes of flight. Upon arrival; we were met at the gate by maintenance and found the left engine jet pipe cowl was unlatched and hanging down.

Original NASA ASRS Text

Title: A CRJ-200 First Officer reported airframe vibration in flight. Upon arrival the left engine jetpipe cowl was found unlatched and hanging down.

Narrative: During my preflight walk-around; no defects were noted with the aircraft. All exterior hatches; doors; and latches were secured or in their expected state. On descent; when I brought the thrust levers back to idle; we experienced a short airframe vibration (approximately 1 second). When we leveled and thrust was at a mid-to-low range; we felt a significant airframe vibration. The left engine fan vibration gauge fluctuated between 2.3 and 2.8; and the left engine oil temperature was significantly lower than the right. During further descent I elected to leave the left engine at idle while we investigated. The vibration did not return for the remaining 5 minutes of flight. Upon arrival; we were met at the gate by Maintenance and found the left engine jet pipe cowl was unlatched and hanging down.

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.

Attributes
ACN	971833
Time
Date	201109
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Regional Jet 200 ER/LR (CRJ200)
Operating Under FAR Part	Part 121
Flight Phase	Descent
Flight Plan	IFR
Component
Aircraft Component	Cowling/Nacelle Fasteners Latches
Person 1
Function	First Officer Pilot Flying
Qualification	Flight Crew Commercial
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Procedural Published Material / Policy

A crj-200 first officer reported airframe vibration in flight. Upon arrival the left engine jetpipe cowl was found unlatched and hanging down.