Cessna T210M N761LX

Summary

On 13 May 2002 at about 20:55 local time, a Cessna T210M registered N761LX was involved in an accident near Groveland, California, United States. 2 people were on board and 2 died. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

13 May 2002 at 20:55

Classification

Accident

Location

Groveland, California, United States

Coordinates

37.8392, -119.8581

Aircraft

Cessna T210M

Registration

N761LX

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Fullerton → Carson City

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

LAX02FA163

2 people died.

a catastrophic engine failure due to the fatigue fracture and failure of the crankshaft. A factor contributing to the accident was the unsuitable nature of the mountainous terrain for a successful forced landing. The precipitating cause of the fatigue fracture could not be determined.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The airplane collided with multiple trees during an attempted forced landing in mountainous terrain following a catastrophic engine failure in cruise. The flight was obtaining VFR flight following from air route traffic control center (ARTCC) when the facility lost radar and radio contact. The airplane came to rest near the edge of an elliptical meadow, which was about 1 mile long by 1/4 mile wide, with the long axis oriented east and west. The meadow was in mountainous terrain and surrounded by trees over 100 feet tall. The debris path was along the eastern edge of the meadow on a magnetic bearing of 210 degrees. Multiple large trees were observed with broken branches and major impact marks on their trunks. The crankcase had a 3-inch diameter hole in it above cylinder number 3. Examination of the engine found that the crankshaft fractured and separated at the rear of the number 4 cheek. The fracture was at the forward radius of the number 2 main bearing journal. Smeared metal was on the fracture surfaces. A metallurgical examination determined that a large portion of the fracture surface exhibited smooth crack arrest markings typical of fatigue propagation. Failure of the crankshaft was caused by a fatigue crack in the cheek between the number 3 rod journal and the number 2 main bearing journal. The fracture of the crankshaft caused the additional damage to the engine, including the separation of the numbers 3 and 4 connecting rods from their respective journals, and would have led to a complete loss of engine power. The origin of the fatigue fracture was in the transition between the number 2 main bearing journal surface and the forward fillet radius, approximately 0.036 inches below the surface of the journal. No metallurgical anomalies or manufacturing process errors were found to explain the fatigue initiation. This failure is very similar to a number of others investigated by the Safety Board's Materials Laboratory in the past, with a fatigue crack initiating just below the hardened case layer. As with many of those previous events, there were no material or microstructural defects that could be identified as the root cause of the fatigue initiation. The crankshaft met design material specifications.

Quoted verbatim from the NTSB record.