Cessna 182 N2725G

Summary

On 6 September 2004 at about 23:45 local time, a Cessna 182 registered N2725G was involved in an accident near Gillette, Wyoming, United States. One person was on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

6 September 2004 at 23:45

Classification

Accident

Location

Gillette, Wyoming, United States

Coordinates

44.1750, -105.6350

Aircraft

Cessna 182

Registration

N2725G

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Casper → Gillette

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

DEN04LA136

Nobody was injured.

improper engine overhaul performed by the mechanic which resulted in the fractured exhaust valve and subsequent partial loss of engine power. Contributing to the accident was the lack of suitable terrain for a forced landing.

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

Read the full NTSB narrative

The pilot stated he was in cruise flight when the engine began to run rough. He heard sounds of grinding metal and shortly thereafter, the "engine began to shake violently." The pilot shut the engine down and attempted a forced landing to a plowed field. During the forced landing, the nose wheel impacted a small rut, separating the nose landing gear tire from the nose landing gear assembly. The airplane nosed over, causing substantial damage. An internal examination of the engine showed the number 3 piston, piston rings, and tension springs, and the number 3 exhaust valve head had fragmented into numerous pieces. These pieces were located in the oil sump. The inside of the crankcase halves showed impact damage in the areas aft of the number 4 piston and forward of the number 3 piston. The top inside of the number 3 cylinder head showed numerous impact marks including a 7/8 inch long, 1/8 inch wide and 1/8 inch deep indentation at one of the spark plug openings, and a 1/2 inch long, 1/8 inch wide, and 1/8 inch deep indentation at the area of the exhaust valve seat which were consistent with a valve head edge impact. The number 3 exhaust valve seat was not present. The number 3 exhaust valve stem was removed and examined. Fractures observed on the valve stem were consistent with an overload failure. The number 3 exhaust valve guide showed elongating distortion. An examination of the crankshaft, camshaft, other cylinders, pistons, valves, and valve springs showed no pre-existing failures. No evidence of the number 3 exhaust valve seat was found among the fractured pieces in the engine. An examination of the remaining airplane systems revealed no anomalies.

Quoted verbatim from the NTSB record.