FlightFinder
Check my flight
No fatalities

Grumman-Schweizer G-164B Engine Failure Leads to Inverted Landing in Cornfield (N6645Q)

Frederick, MD, US

On July 11, 2006, a Grumman-schweizer G-164B (registration N6645Q) operated by Tri State Aero was involved in an aviation accident near Frederick, MD. No fatalities were reported. Investigators recorded the probable cause as: Fractured masterod consistent with exposure to hydraulic lock prior to the accident flight. 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 2026-07-04Data APIEditorial standards

During cruise, the pilot reported rough engine, smoke, and power loss. Emergency landing in cornfield resulted in inverted airplane with substantial damage. Post-accident examination revealed fractured masterod from prior hydraulic lock.

Accident Overview

During cruise flight, the pilot of a Grumman-Schweizer G-164B airplane reported that the engine began to run rough and shake violently. Smoke was observed coming from the exhaust. The engine subsequently lost power, prompting the pilot to perform an emergency landing in a cornfield. Upon touchdown, the airplane came to rest inverted, resulting in substantial damage.

Engine Examination

A post-accident examination of the engine revealed a fractured masterod. The masterod, a critical engine component, was found to be broken. Further analysis of the deformation and damage to the masterod indicated that it was consistent with being exposed to a hydraulic lock prior to the accident flight. Hydraulic lock occurs when incompressible fluid, such as oil, accumulates in a cylinder and prevents piston movement, potentially leading to severe component stress and failure.

Probable cause

Fractured masterod consistent with exposure to hydraulic lock prior to the accident flight.
Engine failure

Frequently asked questions

What happened in the 11 Jul 2006 Grumman-schweizer G-164B accident near Frederick, MD?

During cruise, the pilot reported rough engine, smoke, and power loss. Emergency landing in cornfield resulted in inverted airplane with substantial damage. Post-accident examination revealed fractured masterod from prior hydraulic lock.

Were there any fatalities in the 11 Jul 2006 Grumman-schweizer G-164B accident?

No fatalities were recorded in this accident.

What aircraft was involved and where did it happen?

The accident on 11 Jul 2006 involved a Grumman-schweizer G-164B, registration N6645Q, operated by Tri State Aero, at Frederick, MD.

What was the probable cause of the accident?

Fractured masterod consistent with exposure to hydraulic lock prior to the accident flight.

More accident analyses

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20060809X01119. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.