Incident Overview
While 30 miles north of the destination, the inboard side of the right engine cowl popped loose and began vibrating severely. Concerned that the cowling could break loose and strike the vertical or horizontal stabilizer, the pilot feathered the right engine.
Sequence of Events
The airport was approximately 19 miles away at this point. However, the pilot reported that he could not obtain more than 28-29 inches of manifold pressure on the left engine. He then attempted to restart the right engine. The propeller came out of feather, but the engine would not start. The windmilling propeller caused the rate of descent to increase, making a forced landing imminent.
Landing and Damage
During the landing roll, the nose gear collapsed and the aircraft nosed over onto its back.
Investigation Findings
The right engine fuel selector was found in the OFF position. A subsequent test of the right engine showed it ran normally and reached 34-35 inches of manifold pressure with no abnormalities noted.