An SR22 pilot reported his engine began violently shaking and lost power enroute. The pilot declared...

Attributes
ACN	977911
Time
Date	201111
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.VOR
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	SR22
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Flight Plan	IFR
Component
Aircraft Component	Engine
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Multiengine Flight Crew Instrument Flight Crew Private
Experience	Flight Crew Last 90 Days 50 Flight Crew Total 255 Flight Crew Type 60
Events
Anomaly	Aircraft Equipment Problem Critical

Narrative:

[In flight;] a 'pop' and subsequent violent shaking of the engine occurred which resulted in partial loss of power and subsequent declaration of an emergency with ATC and ultimately a successful diversion and landing at [a suitable airport]. Fuel selector change; mixture change and throttle change did not rectify the situation. On the ground; a run up and magneto check showed no issue with the magnetos. The engine monitoring system showed no output on the number three egt. Preliminary examination and borescope inspection indicate an exhaust valve failure on the number three cylinder. Corrective actions are yet to be taken but preliminarily are thought to be replacement of the number three exhaust valve. Cylinder is being pulled to determine that the preliminary diagnosis is correct. Corrective action will be taken after final root cause is determined.

Original NASA ASRS Text

Title: An SR22 pilot reported his engine began violently shaking and lost power enroute. The Pilot declared an emergency and diverted to a safe landing; where a maintenance inspection revealed failure of the number three cylinder exhaust valve.

Narrative: [In flight;] a 'pop' and subsequent violent shaking of the engine occurred which resulted in partial loss of power and subsequent declaration of an emergency with ATC and ultimately a successful diversion and landing at [a suitable airport]. Fuel selector change; mixture change and throttle change did not rectify the situation. On the ground; a run up and magneto check showed no issue with the magnetos. The engine monitoring system showed no output on the number three EGT. Preliminary examination and borescope inspection indicate an exhaust valve failure on the number three cylinder. Corrective actions are yet to be taken but preliminarily are thought to be replacement of the number three exhaust valve. Cylinder is being pulled to determine that the preliminary diagnosis is correct. Corrective action will be taken after final root cause is determined.

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.

An SR22 pilot reported his engine began violently shaking and lost power enroute. The pilot declared an emergency and diverted to a safe landing; where a maintenance inspection revealed failure of the number three cylinder exhaust valve.