Casualties unknown

1991-10-12: Hughes 269B (N9474F) — Precision Helicopters Inc. — Hillsboro, OR

Hillsboro, OR, US

On October 12, 1991, a Hughes 269B (registration N9474F) operated by Precision Helicopters Inc. was involved in an aviation accident near Hillsboro, OR. Investigators recorded the probable cause as: The pilot allowed rotor RPM to drop out of the green arc while maneuvering over an orchard. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 3 related events involving the same aircraft type or operator are linked below.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 1781061362Data APIEditorial standards

A Hughes 269B helicopter struck an orchard after the pilot allowed rotor RPM to drop during low-level maneuvering to knock hazelnuts from trees. The pilot had not recomputed performance data after adding a passenger and fuel.

Accident Details

A Hughes 269B helicopter was involved in an accident while maneuvering at low altitude over an orchard. The pilot had been using the rotor wash to knock hazelnuts off trees. During the maneuver, the rotor RPM decreased below the green arc.

The pilot reported that he was unable to reduce the collective pitch because of the proximity of the trees. Insufficient forward acceleration prevented the rotor speed from being increased before the helicopter settled into the orchard.

Pilot Statement

After the accident, the pilot stated that he had taken on a passenger and filled the aircraft with fuel prior to the flight. He had not recomputed the performance data to account for the increased weight.

Aircraft and Operations

The helicopter involved was a Hughes 269B. The exact sequence of events leading to the rotor RPM decay was not specified beyond the pilot's actions during the low-level operation over the orchard.

Probable cause

The pilot allowed rotor RPM to drop out of the green arc while maneuvering over an orchard.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X18390. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.