Snow 600 N1691S accident near Nashville, Tennessee

Probable cause

The failure of the propeller shaft seal in flight. Contributing to the accident was the lack of suitable terrain for a forced landing.

NTSB analysis

The owner of the Snow 600 aerial application airplane stated that the airplane had not been flown “in some time.” The airplane was equipped with a Pratt & Whitney R-1340 series engine. According to the pilot, he agreed to reposition the airplane to another airport as a favor for the owner. The day before the flight, the pilot examined the airplane, and conducted an engine run-up to assure himself that the airplane appeared to be acceptable for flight. He reported some minor airframe discrepancies to the owner, and these were rectified prior to the accident flight. The airplane was not flown between the pilot's initial examination and the accident flight. Several minutes after takeoff on the positioning flight, the pilot noted that oil began to coat his windshield, and he saw white smoke emanating from the engine area. He selected a field for a forced landing, and conducted an uneventful touchdown. During the rollout, the right wing struck a tree, approximately 3 feet inboard from the wingtip. The airplane partially rotated around the tree, and the right main landing gear and tailwheel were damaged. Postaccident examination by a Federal Aviation Administration inspector and a mechanic revealed that oil had leaked from an undetermined location at the forward end of the engine near the propeller shaft and hub assembly.

Text from the NTSB. Open the NTSB docket for ERA09CA054 for the full record.