No fatalities

Aerial Application Flight Ends in Collision Following Precautionary Landing (N897X)

Gridley, CA, US

On July 11, 2000, a Grumman G-164A (registration N897X) operated by Williams AG Service, Inc. was involved in an aviation accident near Gridley, CA. No fatalities were reported. Investigators recorded the probable cause as: A partial loss of engine power due to the failure of an exhaust valve during an aerial application flight. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 1 related events involving the same aircraft type or operator are linked below.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 2026-07-04Data APIEditorial standards

An aerial application pilot experienced engine trouble, made a precautionary landing on a field road, and collided with a dirt berm during rollout. Engine inspection revealed a separated exhaust valve head.

Event Summary

While maneuvering during an aerial application flight, the pilot heard an unusual engine noise, experienced a loss of engine oil pressure, observed smoke, and lost partial power. The pilot made a precautionary landing on a nearby field road. During the landing rollout, the airplane collided with a dirt berm.

Engine Inspection

An inspection of the engine revealed that its No. 2 cylinder exhaust valve head had separated and subsequently broke the cylinder. The engine's total time was estimated at 9,300 hours, and it had been operated about 708.8 hours since last receiving a major overhaul.

Frequently asked questions

What happened in the 11 Jul 2000 Grumman G-164A accident near Gridley, CA?

An aerial application pilot experienced engine trouble, made a precautionary landing on a field road, and collided with a dirt berm during rollout. Engine inspection revealed a separated exhaust valve head.

Were there any fatalities in the 11 Jul 2000 Grumman G-164A accident?

No fatalities were recorded in this accident.

What aircraft was involved and where did it happen?

The accident on 11 Jul 2000 involved a Grumman G-164A, registration N897X, operated by Williams AG Service, Inc., at Gridley, CA.

What was the probable cause of the accident?

A partial loss of engine power due to the failure of an exhaust valve during an aerial application flight.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X21506. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.