Casualties unknown

1985-09-21: Bell 47G-2 (N2874B) — Helicair Ag, Inc. — Watsonville, CA

Watsonville, CA, US

On September 21, 1985, a Bell 47G-2 (registration N2874B) operated by Helicair Ag, Inc. was involved in an aviation accident near Watsonville, CA. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 2 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

During an agricultural flight at about 5 feet above ground level, a loud bang accompanied by engine overspeed and loss of rotor power occurred. The pilot attempted an immediate landing but lacked altitude for autorotation. The aircraft touched down, bounced, and the main rotor blades flexed downward, severing the tail boom. Examination of the clutch and freewheeling unit revealed anomalies, but the primary component failure is unknown.

Event Description

An agricultural flight was in progress when, at approximately 5 feet above ground level, the pilot heard a loud bang. The engine subsequently oversped, and all power to the rotor blades was lost. The pilot attempted to land immediately in the underlying field but had insufficient altitude and airspeed to perform an autorotation. The aircraft touched down, bounced, and during the bounce, the main rotor blades flexed downward and severed the tail boom.

Post-Accident Examination

Examination of the clutch revealed that poor contact was being made between the shoes and the drum. Examination of the freewheeling unit revealed that it contained numerous rollers that would not lock. These findings suggest potential mechanical issues, but the relationship between the two components and the sequence of failures could not be determined.

Unknown Primary Failure

It is unknown which component's failure was primary. The investigation did not establish a definitive causal link between the observed clutch condition, the freewheeling unit condition, and the power loss event. The aircraft's damage included the severed tail boom, but no further details regarding other damage or injuries are available.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001214X37826. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.