On August 10, 1994, a Grumman G-164B (registration N8251K) was involved in an aviation accident near Matagorda, TX. Investigators recorded the probable cause as: The failure of the number 4 cylinder near the exhaust valve, which resulted in a loss of engine power and the subsequent collision with trees during an attempted emergency landing. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During a crop dusting flight, the pilot lost engine power due to a cracked cylinder and attempted an emergency landing on a dirt road, resulting in a collision with trees.
What happened
The aircraft was engaged in an agricultural spraying mission over a rice field when the engine began backfiring. The pilot subsequently experienced a complete loss of power. In response to the mechanical failure, the pilot jettisoned the chemical load and attempted to execute an emergency landing on a nearby dirt road. While maneuvering for the landing approach, the airplane collided with trees.
The investigation
A post-accident examination of the engine was conducted to determine the cause of the power loss. The inspection revealed a crack in the number 4 cylinder near the exhaust valve. This mechanical defect is consistent with the reported backfiring and subsequent failure of the engine during the operation.
Findings
The investigation identified the structural failure of the engine component as the primary factor in the incident. The pilot's decision to jettison the load was a standard procedure for weight reduction, but the mechanical integrity of the powerplant could not be maintained. The collision with trees occurred during the final phase of the emergency landing attempt.
Probable cause
The failure of the number 4 cylinder near the exhaust valve, which resulted in a loss of engine power and the subsequent collision with trees during an attempted emergency landing.