A B737 crew at FL380 in level flight; experienced a loud engine report accompanied by a strong airfr...

Narrative:

The flight [was] in cruise at FL370. Clear weather conditions; smooth air. Without warning; we experienced a loud 'bang' accompanied with strong airframe vibration. Number 2 engine N1 started fluctuating between set power and 50% without moving the thrust lever. This continued as we analyzed the situation; so proceeded to 'engine failure' QRH checklist; which led us to shut down the engine. (Later; during the descent; we also reviewed the 'engine limit or surge or stall' checklist; which led to the same conclusion.) after completing QRH; I gave aircraft control to the first officer and proceeded to tell ATC that we are declaring an emergency due to engine failure and initiated diversion to an airport now about 15 NM to our north. Then called dispatch via VHF airinc and advised them of the situation and my intentions. Then [I] gave the cabin crew a full briefing on the situation; then a PA to the passengers. Remainder of descent and landing went according to plan and training via the one engine inop approach and landing procedures. Landing was overweight by 3;300 pounds; but smooth and uneventful. Taxi to parking was normal. Passengers were required to stay on the aircraft for about 40 minutes from that point until airport personnel could arrive with air stairs and open the terminal building; but no complications.

Original NASA ASRS Text

Title: A B737 crew at FL380 in level flight; experienced a loud engine report accompanied by a strong airframe vibration and surging power. They completed the ENGINE FAILURE QRH; declared an emergency and diverted to a nearby airport.

Narrative: The flight [was] in cruise at FL370. Clear weather conditions; smooth air. Without warning; we experienced a loud 'bang' accompanied with strong airframe vibration. Number 2 Engine N1 started fluctuating between set power and 50% without moving the thrust lever. This continued as we analyzed the situation; so proceeded to 'Engine Failure' QRH checklist; which led us to shut down the engine. (Later; during the descent; we also reviewed the 'Engine limit or surge or stall' checklist; which led to the same conclusion.) After completing QRH; I gave aircraft control to the First Officer and proceeded to tell ATC that we are declaring an emergency due to engine failure and initiated diversion to an airport now about 15 NM to our north. Then called Dispatch via VHF AIRINC and advised them of the situation and my intentions. Then [I] gave the cabin crew a full briefing on the situation; then a PA to the passengers. Remainder of descent and landing went according to plan and training via the One Engine Inop Approach and Landing procedures. Landing was overweight by 3;300 LBS; but smooth and uneventful. Taxi to parking was normal. Passengers were required to stay on the aircraft for about 40 minutes from that point until airport personnel could arrive with air stairs and open the terminal building; but no complications.

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.

Attributes
ACN	1111944
Time
Date	201308
Local Time Of Day	0001-0600
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Component
Aircraft Component	Turbine Engine
Person 1
Function	Captain Pilot Flying
Experience	Flight Crew Last 90 Days 150 Flight Crew Total 13000 Flight Crew Type 5000
Events
Anomaly	Aircraft Equipment Problem Critical

A B737 crew at FL380 in level flight; experienced a loud engine report accompanied by a strong airframe vibration and surging power. They completed the engine failure QRH; declared an emergency and diverted to a nearby airport.