Casualties unknown

1983-03-24: Air Tractor AT-301 (N3652A) — Newellton, LA

Newellton, LA, US

On March 24, 1983, an Air Tractor AT-301 (registration N3652A) was involved in an aviation accident near Newellton, LA. Investigators recorded the probable cause as: A crack in the number 7 cylinder that held the intake valve open, resulting in engine power loss. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 1781061362Data APIEditorial standards

An aircraft suffered an engine failure approximately one minute after takeoff, leading to a forced landing where the plane flipped inverted, causing significant structural damage.

What happened

Approximately one minute after takeoff, the aircraft experienced a sudden loss of power as the engine failed. The pilot attempted to execute a forced landing under emergency conditions. During this maneuver, the aircraft flipped into an inverted position before coming to rest on the ground.

The impact resulted in substantial structural damage to the airframe. Specifically, one wing tip and the vertical stabilizer were damaged during the inversion and subsequent crash sequence.

The investigation

A post-crash inspection of the wreckage was conducted to determine the mechanical cause of the engine failure. Investigators examined the engine components for signs of malfunction or pre-existing defects that could have led to the power loss.

The inspection revealed a significant crack in the number 7 cylinder. This fracture extended from the spark plug hole to the opposite side of the spark plug, effectively spanning the width of the cylinder head. The damage appeared to have held the intake valve open during operation.

Findings

The mechanical failure was directly linked to the structural integrity of the engine's number 7 cylinder. The crack prevented the intake valve from sealing properly, which resulted in a loss of compression and subsequent power loss. This mechanical issue caused the engine to fail shortly after takeoff, leading to the forced landing and the inverted crash.

The sequence of events indicates that the engine failure was the primary factor in the accident. The inability to maintain power prevented the pilot from completing the climb or reaching a suitable landing area, necessitating an emergency landing that resulted in the aircraft flipping.

Probable cause

A crack in the number 7 cylinder that held the intake valve open, resulting in engine power loss.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001214X42449. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.