Cessna 140 N76379

Summary

On 9 December 2006 at about 20:30 local time, a Cessna 140 registered N76379 was involved in an accident near Vienna, Missouri, 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

9 December 2006 at 20:30

Classification

Accident

Location

Vienna, Missouri, United States

Coordinates

38.9258, -91.9161

Aircraft

Cessna 140

Registration

N76379

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Rolla/Vichy → Gardner

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

CHI07LA039

Nobody was injured.

The loss of engine power during cruise flight due to fatigued crankshaft cluster gear bolts and the inadequate major overhaul of the engine that was last performed by other maintenance personnel. An additional cause was a subsequent major engine overhaul not performed by the pilot after he purchased the airplane and operated it with an engine that exceeded the engine manufacturer's time between overhaul criteria.

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

Read the full NTSB narrative

The airplane impacted terrain during a forced landing after a loss of engine power. The pilot recently purchased the airplane and had taken delivery of it on the day of the accident. Examination of the engine revealed three of the crankshaft cluster gear bolts were fractured completely through. The bolt fracture surface features were consistent with fatigue. Additionally, the crankshaft gear had a hole where a crankshaft dowel had been installed following a design change in 1948 and was reflected in subsequent maintenance manuals. The dowel is used as a reference in machining the crankshaft. During the disassembly, the tappets fell out when the engine was overturned during the disassembly. It was later noted that the tappets did not contain retaining hardware. The interior of the crankcase halves contained a black colored residue when the oil was drained. Logbook entries show that the engine was last overhauled on July 25, 1990, and accumulated a total time since overhaul of 257.5 hours. Teledyne Continental Service Information Letter, SIL98-9A, Time Between Overhaul Periods, states that engines are to be overhauled at least every twelve years.

Quoted verbatim from the NTSB record.