A C182 pilot described an engine vibration which forced him to declare an emergency and divert to a ...

Narrative:

I was approaching the area over the foothills at 3;500 and ready to descend quickly once I clear the hills. I had flight following and was talking with TRACON. I was beneath the class B and needed to descend to get under nearby class C airspace before approaching my destination. When I pulled the power back to descend the engine started to shake. I checked everything and the shaking got worse so I pulled it back to idle. It was vibrating so badly I was afraid it would break the mount. Not a good place for an engine failure; with mountains below and urban sprawl on both sides. My options were to try to land on a ridge top; try to stretch it to the salt flats or a nearby airport; or last and certainly least look for a soft street. I was about 8 miles from the divert airport and I found I could maintain enough power to keep the descent rate to about 3-400 ft/min and 80 KTS so I declared an emergency with TRACON and went for diversion airport. Tower cleared me for anything I wanted so I took the long runway. I was high when I was about a mile out so I slipped it down and landed without further incident followed by the fire trucks and ambulance. I've been advised to file this report for the record. I contacted ATC afterward and was told no further action was required on my part since there was no accident to report. The cause was catastrophic internal failure of the engine leading to a hole in the case and loss of oil. The engine was running fine prior to the power reduction.

Original NASA ASRS Text

Title: A C182 Pilot described an engine vibration which forced him to declare an emergency and divert to a nearby airport. He later determined that a catastrophic failure caused a hole in the crank case.

Narrative: I was approaching the area over the foothills at 3;500 and ready to descend quickly once I clear the hills. I had flight following and was talking with TRACON. I was beneath the Class B and needed to descend to get under nearby Class C airspace before approaching my destination. When I pulled the power back to descend the engine started to shake. I checked everything and the shaking got worse so I pulled it back to idle. It was vibrating so badly I was afraid it would break the mount. Not a good place for an engine failure; with mountains below and urban sprawl on both sides. My options were to try to land on a ridge top; try to stretch it to the salt flats or a nearby airport; or last and certainly least look for a soft street. I was about 8 miles from the divert airport and I found I could maintain enough power to keep the descent rate to about 3-400 ft/min and 80 KTS so I declared an emergency with TRACON and went for diversion airport. Tower cleared me for anything I wanted so I took the long runway. I was high when I was about a mile out so I slipped it down and landed without further incident followed by the fire trucks and ambulance. I've been advised to file this report for the record. I contacted ATC afterward and was told no further action was required on my part since there was no accident to report. The cause was catastrophic internal failure of the engine leading to a hole in the case and loss of oil. The engine was running fine prior to the power reduction.

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	906041
Time
Date	201008
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Skylane 182/RG Turbo Skylane/RG
Operating Under FAR Part	Part 91
Flight Phase	Descent
Route In Use	Visual Approach
Flight Plan	None
Component
Aircraft Component	Engine
Person 1
Function	Single Pilot
Qualification	Flight Crew Commercial Flight Crew Instrument
Experience	Flight Crew Last 90 Days 75 Flight Crew Total 1600 Flight Crew Type 1300
Events
Anomaly	Aircraft Equipment Problem Critical

A C182 pilot described an engine vibration which forced him to declare an emergency and divert to a nearby airport. He later determined that a catastrophic failure caused a hole in the crank case.