Casualties unknown

1993-08-15: Hughes 369D (N8606F) — Butte County Sheriffs's Dept — Chico, CA

Chico, CA, US

On August 15, 1993, a Hughes 369D (registration N8606F) operated by Butte County Sheriffs's Dept was involved in an aviation accident near Chico, CA. Investigators recorded the probable cause as: the observer's failure to properly secure stowed items in the rear compartment prior to takeoff and the resultant foreign object damage to the tail rotor system which precluded the pilot from maintaining directional control. 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

A sheriff's department helicopter experienced a loud bang and severe vibration at 500 feet, forcing an autorotation landing. The helicopter rolled over during flare. A missing nomex flight suit was later found shredded in an orchard.

Incident Overview

A helicopter operated under a rental agreement by a sheriff's department for surveillance and rescue missions experienced an in-flight emergency shortly after reaching a cruise altitude of 500 feet above ground level. The aircraft had all doors removed for its mission. The pilot reported hearing a loud bang and feeling a severe vibration throughout the airframe. He initiated a 180-degree autorotation with power toward a clear area in an almond orchard.

Landing and Rollover

During the landing flare, the helicopter began a right spin when the pilot applied collective pitch. The pilot immediately rolled off the power, and the helicopter landed hard, subsequently rolling over.

Witness Account

A ground witness observed the helicopter nearly overhead and reported seeing a cloth-like object exit the helicopter and fly back toward the tail. The helicopter then descended rapidly while turning 180 degrees until it disappeared behind trees.

Post-Accident Findings

Before takeoff, an observer had placed a nomex flight suit under bags tied down in the rear compartment. After the accident, examination of the helicopter and the accident site revealed that the flight suit was unaccounted for and could not be located. Several days later, a search party discovered a shredded nomex flight suit in the orchard not far from the accident site and back along the helicopter's flight path.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001211X13175. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.