Cessna 310F N6762X accident near Lagrange, Indiana

Probable cause

The pilot did not maintain altitude due to his distracted attention to a vibration of unknown origin.

NTSB analysis

The pilot stated that, during cruise flight, he noticed a sudden airplane vibration, decreased controllability, and a loss of altitude. He initially thought that the vibration was coming from the empennage but later thought it was from the left engine. He stated that the engine instrument indications for both engines were normal. He elected to shut down the left engine, but the vibration and altitude loss continued. The pilot performed an off-airport landing to a pasture, and the airplane collided with obstacles. During postaccident examination, no airframe anomalies that would have induced a vibration were noted. Testing of the right engine did not reveal any anomalies that would have induced a vibration or precluded normal operation. The airplane owner's manual performance information indicated that the airplane was capable of climbing at a rate of about 500 feet per minute with one engine inoperative at the conditions that were present at the time of the accident. Given that no anomalies were found with the airframe or the right engine and that the airplane had climb performance capability even with one engine inoperative, it is likely that the pilot was distracted by the vibration and did not maintain altitude.

Text from the NTSB. Open the NTSB docket for CEN10LA494 for the full record.