B737 flight crew reported an engine failure during cruise resulting in a diversion.

Attributes
ACN	1711664
Time
Date	201912
Local Time Of Day	1801-2400
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	Engine
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine Flight Crew Instrument
Experience	Flight Crew Last 90 Days 55 Flight Crew Total 348 Flight Crew Type 348
Person 2
Function	First Officer Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine Flight Crew Instrument
Experience	Flight Crew Last 90 Days 30 Flight Crew Total 10202 Flight Crew Type 10202
Events
Anomaly	Aircraft Equipment Problem Critical

Narrative:

While cruising at FL320; #2 engine made a loud 'boom' sound; N1 dropped about 20%; and vibration commenced. Autothrottle disengaged on its own. After testing thrust lever modulation to confirm engine vibration; I directed first officer to accomplish engine high vibration QRH checklist. Requested priority handling with ATC. There was never a non-normal indication on the #2 vibration gauge (it never displayed above 0.8) but vibration was obvious. With #2 thrust lever at idle position; vibration largely ceased and engine remained at idle for remainder of flight. I ran test with purser and made PA to passengers. First officer attempted to contact maintenance control through arinc but that ultimately proved difficult and I directed him to abort that effort to support me for arrival. Workload management at times was somewhat challenging. I directed first officer to perform one engine inoperative QRH checklist. Remainder of flight was run per single-engine SOP. Approach and landing uneventful. I had forgotten to select an autobrake setting but the aircraft stopped easily with manual braking. Excellent support from airport emergency services once on the ground. Fire crews looked at engine and noted no visible defects. Uneventful taxi to gate except that engine generated notable smoke cloud at shutdown; which was noted by fire crew. We deplaned passengers via jetway.

Original NASA ASRS Text

Title: B737 flight crew reported an engine failure during cruise resulting in a diversion.

Narrative: While cruising at FL320; #2 engine made a loud 'boom' sound; N1 dropped about 20%; and vibration commenced. Autothrottle disengaged on its own. After testing thrust lever modulation to confirm engine vibration; I directed First Officer to accomplish ENGINE HIGH VIBRATION QRH checklist. Requested priority handling with ATC. There was never a non-normal indication on the #2 vibration gauge (it never displayed above 0.8) but vibration was obvious. With #2 thrust lever at idle position; vibration largely ceased and engine remained at idle for remainder of flight. I ran TEST with purser and made PA to passengers. First Officer attempted to contact Maintenance Control through ARINC but that ultimately proved difficult and I directed him to abort that effort to support me for arrival. Workload management at times was somewhat challenging. I directed First Officer to perform ONE ENGINE INOPERATIVE QRH checklist. Remainder of flight was run per single-engine SOP. Approach and landing uneventful. I had forgotten to select an autobrake setting but the aircraft stopped easily with manual braking. Excellent support from airport emergency services once on the ground. Fire crews looked at engine and noted no visible defects. Uneventful taxi to gate except that engine generated notable smoke cloud at shutdown; which was noted by fire crew. We deplaned passengers via jetway.

Data retrieved from NASA's ASRS site 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.