Casualties unknown

1989-06-21: Grumman-schweizer G-164A (N9830) — Gaudry AG Services, Inc. — Battle Mountain, NV

Battle Mountain, NV, US

On June 21, 1989, a Grumman-schweizer G-164A (registration N9830) operated by Gaudry AG Services, Inc. was involved in an aviation accident near Battle Mountain, NV. Investigators recorded the probable cause as: The loss of engine power due to a broken number two rocker arm, which led to a forced landing where the pilot stalled the aircraft while attempting to avoid a vehicle on the road. 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

During cruise flight, an aircraft experienced a sudden loss of engine power. The pilot attempted a forced landing on a road but stalled while flaring high to avoid a vehicle, resulting in a hard landing and the aircraft nosing over into a ditch.

What happened

While the aircraft was operating in cruise flight, the engine suddenly lost power. The pilot initiated an immediate forced landing procedure, selecting a nearby road as the intended touchdown zone. As the aircraft approached the road surface, the pilot detected a vehicle present on the roadway. To avoid colliding with this obstacle, the pilot pulled back on the controls to flare higher than normal.

This excessive pitch-up attitude caused the aircraft to lose airspeed rapidly and stall just above the ground. The aircraft then descended hard onto the road surface. Upon impact, the nose gear collapsed, causing the aircraft to nosed over and come to rest in an adjacent ditch after striking a fence.

The investigation

Following the accident, investigators conducted a detailed inspection of the airframe and propulsion system to determine the root cause of the power loss. Examination of the engine revealed significant internal mechanical failure. Specifically, a broken number two rocker arm was found within the engine assembly. This component failure is consistent with the sudden loss of power observed during the cruise phase of flight.

Findings

The investigation determined that the primary factor leading to the accident was the mechanical failure of the engine due to the broken rocker arm. Contributing to the severity of the damage was the pilot's decision to flare high to avoid a ground obstacle, which resulted in a stall and hard landing. The aircraft sustained substantial damage to the nose section and landing gear.

Probable cause

The loss of engine power due to a broken number two rocker arm, which led to a forced landing where the pilot stalled the aircraft while attempting to avoid a vehicle on the road.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001213X28681. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.