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Casualties unknown

Propeller Pitch Control Failure After Spraying Operations (N8945H)

Biscoe, AR, US

On March 14, 1984, a Schweizer G-164A (registration N8945H) was involved in an aviation accident near Biscoe, AR. 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

After spraying operations, pressure washing introduced water into propeller pitch change bearings, causing corrosion. Corrosion hindered pitch movement; a counterweight bolt broke, allowing blade pitch increase. Engine RPM dropped, pilot shut down and landed in a field, resulting in a nose-over during landing roll.

Incident Description

Following the completion of spraying operations, the aircraft's propeller was routinely cleaned using a pressure sprayer. This cleaning method allowed water to penetrate the propeller's pitch change bearings. The moisture caused the bearings to corrode, and the corrosion developed into rust that gradually impeded the movement of the pitch change mechanism. As a result of the corrosion, the blade counterweight bolt eventually fractured. The bolt's failure permitted the propeller blade pitch to increase uncontrollably. Consequently, engine RPM dropped below the normal operating range. The pilot responded by shutting down the engine and executing a landing in a field. During the landing roll, the aircraft nosed over.

Frequently asked questions

What happened in the 14 Mar 1984 Schweizer G-164A accident near Biscoe, AR?

After spraying operations, pressure washing introduced water into propeller pitch change bearings, causing corrosion. Corrosion hindered pitch movement; a counterweight bolt broke, allowing blade pitch increase. Engine RPM dropped, pilot shut down and landed in a field, resulting in a nose-over during landing roll.

What aircraft was involved and where did it happen?

The accident on 14 Mar 1984 involved a Schweizer G-164A, registration N8945H, at Biscoe, AR.

More accident analyses

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001214X39129. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.