Cessna 152 N67797

Summary

On 26 October 2001 at about 00:40 local time, a Cessna 152 registered N67797 was involved in an accident near Bethany, Oklahoma, 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

26 October 2001 at 00:40

Classification

Accident

Location

Bethany, Oklahoma, United States

Coordinates

35.4992, -97.6404

Aircraft

Cessna 152

Registration

N67797

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Instructional

Phase of flight

Not recorded

Route

Duncan → Bethany

Aircraft damage

Substantial

Weather

VMC

Light

Night

NTSB number

FTW02LA021

Nobody was injured.

the mechanic's failure to properly lock the exhaust valve's clearance adjusting screw locknut, which resulted in a loose nut, disabling of the exhaust valve pushrod, and a partial loss of engine power while in cruise flight. A contributing factor was the night light conditions for the forced landing.

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

Read the full NTSB narrative

The private pilot reported that during a night cross-country flight, the engine began to lose power. The pilot could not maintain altitude to reach the airport, and therefore, elected to land in a field. The pilot landed the airplane in a field where it impacted a barbed wire fence. An FAA airworthiness inspector examined the engine with the assistance of an aircraft mechanic. The FAA inspector reported that they removed the #2 cylinder's rocker arm cover and noted that "the exhaust valve adjuster 'lock nut' had loosened and come completely off." Review of a maintenance record entry dated May 21, 2000, revealed that the #2 cylinder had been removed, repaired, and reinstalled at an aircraft total time of 825.0 hours. On August 13, 2001, the airplane and engine underwent their most recent 100-hour inspection at an aircraft and engine total time of 1,077.0 hours. The aircraft total time at the time of the accident is unknown. According to the engine operator's manual, persons installing pushrods for a cylinder are instructed to recheck the tappet clearance after run-in and lock the valve clearance adjusting screw in place with the locknut.

Quoted verbatim from the NTSB record.