Casualties unknown

2004-08-15: American Champion (acac) 7ECA (N11037) — Manchester, CA

Manchester, CA, US

On August 15, 2004, an American Champion (acac) 7ECA (registration N11037) was involved in an aviation accident near Manchester, CA. Investigators recorded the probable cause as: maintenance personnel's failure to adequately torque the top spark plug on the number one cylinder, which resulted in a separation of that plug and a loss of engine power. 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 airplane experienced a loss of engine power during cruise flight, leading to a forced landing. The aircraft struck transmission wires and touched down hard. The top spark plug was missing from the right rear cylinder, and ignition leads were loose.

Incident Overview

During cruise flight, the engine began to vibrate severely and then "exploded," according to the pilot. The pilot configured the airplane for gliding and selected a field for a forced landing. While on final approach to the intended landing surface, the airplane collided with transmission lines. It continued descending and touched down hard on the field.

Mechanical Findings

Post-incident examination revealed that the top spark plug was absent from the right rear cylinder—identified as the number one cylinder. Additionally, several ignition leads were found loose. The engine had undergone its annual inspection only 1.97 hours before the accident.

Pilot's Perspective

The pilot expressed the opinion that the accident could have been prevented if the spark plug had been tightened or properly torqued during the recent inspection.

Additional Context

No further details regarding the aircraft type, registration, or occupant status were provided in the source material.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20040817X01241. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.