PA23 pilot experiences a 'tremble' shortly after leveling off at 2;000 feet; followed by the right e...

Attributes
ACN	1180737
Time
Date	201406
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	PA-23-250 Aztec
Operating Under FAR Part	Part 135
Flight Phase	Cruise
Route In Use	Vectors
Flight Plan	None
Component
Aircraft Component	Propeller Control
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Commercial Flight Crew Flight Instructor Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 42 Flight Crew Total 3900 Flight Crew Type 30
Events
Anomaly	Aircraft Equipment Problem Critical

Narrative:

On departure; shortly after level off for cruise flight the aircraft began to 'tremble.' as we were jointly diagnosing the symptom; the right engine feathered on its own. Immediately before the event; it was noted by both of us that the other engine was operating at an elevated oil temperature. It was also noted that oil pressures (both engines) were acceptably normal. Upon feathering (independent of pilot action) the oil pressure and manifold pressure dropped. I secured the failed engine; trimmed for level flight; declared an emergency on the approach control frequency; reversed course and held altitude until appropriate. I accepted emergency assistance to be on standby; the landing was uneventful; and we were able to taxi all the way to parking.

Original NASA ASRS Text

Title: PA23 pilot experiences a 'tremble' shortly after leveling off at 2;000 feet; followed by the right engine feathering on its own. The engine is secured and the flight returns to the departure airport.

Narrative: On departure; shortly after level off for cruise flight the aircraft began to 'tremble.' As we were jointly diagnosing the symptom; the right engine feathered on its own. Immediately before the event; it was noted by both of us that the OTHER engine was operating at an elevated oil temperature. It was also noted that oil pressures (both engines) were acceptably normal. Upon feathering (independent of pilot action) the oil pressure and manifold pressure dropped. I secured the failed engine; trimmed for level flight; declared an emergency on the Approach Control Frequency; reversed course and held altitude until appropriate. I accepted emergency assistance to be on standby; the landing was uneventful; and we were able to taxi all the way to parking.

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.