BE350 captain reported experiencing vibrations in the number 2 engine; followed by sparks coming fro...

Narrative:

We encountered a 1Rev vibration throughout the entire airframe. We were in a descent out of 16;000 feet for 12;000 feet. The vibration lasted approximately 2 minutes and then stopped. When the vibration ceased; we noticed sparks coming out of the number 2 engine nacelle vent on the top of the nacelle. All engine indications to include electrical were normal. A decision to secure the engine was made. [Pilot not flying (PNF)] was in contact with ATC for priority handling due to shutting down an engine and divert requests. We decided to divert to ZZZ due to the length of the runway and crash rescue on the field. PNF handled ATC instructions while PIC/training captain assisted me with the engine shutdown checklist and single engine approach/landing checklist. We met in the middle and briefed all aspects of the current situation and the approach/landing. A single engine landing was made with no further incident. Post flight revealed the air conditioning clutch came apart causing clutch parts to come in contact with the nacelle door. No fire was seen or indications noticed.

Original NASA ASRS Text

Title: BE350 Captain reported experiencing vibrations in the Number 2 engine; followed by sparks coming from the nacelle. A post flight inspection revealed a catastrophic failure of an air conditioning clutch.

Narrative: We encountered a 1Rev vibration throughout the entire airframe. We were in a descent out of 16;000 feet for 12;000 feet. The vibration lasted approximately 2 minutes and then stopped. When the vibration ceased; we noticed sparks coming out of the Number 2 engine nacelle vent on the top of the nacelle. All engine indications to include electrical were normal. A decision to secure the engine was made. [Pilot Not Flying (PNF)] was in contact with ATC for priority handling due to shutting down an engine and divert requests. We decided to divert to ZZZ due to the length of the runway and crash rescue on the field. PNF handled ATC instructions while PIC/Training Captain assisted me with the Engine Shutdown Checklist and Single Engine Approach/Landing Checklist. We met in the middle and briefed all aspects of the current situation and the approach/landing. A single engine landing was made with no further incident. Post flight revealed the air conditioning clutch came apart causing clutch parts to come in contact with the nacelle door. No fire was seen or indications noticed.

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.

Attributes
ACN	1537341
Time
Date	201804
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.TRACON
State Reference	US
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Make Model Name	Super King Air 350
Operating Under FAR Part	Part 135
Flight Phase	Descent
Flight Plan	IFR
Component
Aircraft Component	Accessory Drive Section
Person 1
Function	Pilot Flying Captain Check Pilot
Qualification	Flight Crew Instrument Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 150 Flight Crew Total 8000 Flight Crew Type 3000
Events
Anomaly	Aircraft Equipment Problem Critical

BE350 captain reported experiencing vibrations in the number 2 engine; followed by sparks coming from the nacelle. A post flight inspection revealed a catastrophic failure of an air conditioning clutch.