NTSB Factual Report

On October 27, 2004, about 0948 central daylight time, a Cessna T210N, N6108Y, registered to and operated by Flight Express, Inc., as flight 615, experienced a loss of engine power shortly after takeoff and nosed over during a forced landing in a field near Raymond, Mississippi. Instrument meteorological conditions prevailed at the time and an instrument flight rules flight plan was filed for the 14 CFR Part 135 non-scheduled, domestic, cargo flight from Hawkins Field Airport, Jackson, Mississippi, to William P. Hobby Airport, Houston, Texas. The airplane was destroyed by a postcrash fire and the commercial-rated pilot, the sole occupant, sustained minor injuries. The flight originated about 0930, from Hawkins Field Airport.

The pilot stated that after takeoff, the flight climbed to 6,000 feet mean sea level (msl), and as soon as the flight leveled off, he heard a "loud bang" and felt the airframe shaking. The cockpit then filled with smoke, and he requested a vector to the nearest airport. He attempted to keep the engine running but was unsuccessful. The flight descended and broke out of the clouds at 200 feet above ground level where he slowed the airplane to less than the best glide airspeed to clear power lines. The airplane landed "rather hard" in a field against furrows and nosed over then burst into flames. He exited the airplane from the pilot's window.

The engine was examined and completely disassembled by representatives of the operator and the engine manufacturer with Federal Aviation Administration oversight. The oil sump exhibited impact and thermal damage; the drain plug was tight and safety wired. The left and right crankcase halves were missing sections near the backbone in line with the centerline of the No. 2 cylinder bore. Additionally, the crankcase was fractured at the sump rail and included the area of the No. 1 cylinder intake and exhaust tappet bores. The oil pick-up tube was not failed; the oil suction screen was unrestricted. The oil pump housing cavity contained heavy scratches consistent with hard particle passage. The oil pump drive shaft and gears were not fractured, while the oil pressure relief valve had signatures of material being lodged between it and the oil pump housing seating area. Examination of both crankcase halves revealed fretting primarily at the main bearing support faying surfaces. The Nos. 1, 4, and 5 main bearing supports exhibited bearing tang rotational loading, but no lock tang slot elongation. The No. 2 main bearing support exhibited bearing lock tang slot elongation and bearing rotation signatures. The No. 2 main bearing block tangs were damaged from bearing rotation; the remaining main bearing lock tang's were not fractured. The No. 3 main bearing support exhibited bearing lock tang slot elongation and bearing tang rotational loading. All main bearing and connecting rod journals of the crankshaft exhibited scoring in varying degrees from lack lubrication. The Nos. 1 and 2 connecting rods were fractured, and one of the connecting rod bolts for the No. 3 cylinder connecting rod; necking of the bolt was noted. The connecting rod bearings for the Nos. 1 and 2 cylinders were not identified, while the other connecting rod bearings exhibited evidence of lubrication distress.

NTSB review of the maintenance records revealed that the engine was last overhauled on October 1, 2002, and installed in the accident airplane on October 28, 2002. Further review of the maintenance records revealed no evidence that any cylinders had been removed and/or replaced since the engine was overhauled. The operator reported that the engine had accumulated 1,297 hours since being overhauled at the time of the failure.

NTSB Probable Cause

The total loss of engine power which was initiated by fretting of the crankcase halves for undetermined reasons, causing rotation of several of the main bearings, oil starvation, and subsequent failure of several of the connecting rods. A contributing factor was the rough terrain.