Casualties unknown

Aircraft Collides with Ground During Takeoff Attempt (N4099G)

Winterhaven, CA, US

On August 1, 1984, a Bell 47G-5A (registration N4099G) was involved in an aviation accident near Winterhaven, CA. Investigators recorded the probable cause as: The pilot inadvertently allowed the rotor RPM to decay. 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 loading with 60 gallons of pesticide, a pilot began takeoff. The aircraft became airborne, traveled about 300 feet, then rotor RPM decayed, causing descent. The left skid dug into soft soil, pitching the aircraft forward; it came to rest upright.

Accident Details

The accident occurred during a takeoff attempt. According to the pilot, the aircraft was loaded with 60 gallons of pesticide before takeoff was initiated. The aircraft became airborne and traveled approximately 300 feet when the pilot inadvertently allowed the rotor RPM to decay, causing the aircraft to descend.

Impact Sequence

Prior to impact, the pilot attempted to regain rotor RPM but was unsuccessful. The left skid dug into soft soil, causing the aircraft to pitch forward. The aircraft then came to rest in an upright position.

Findings

The investigation determined that the pilot inadvertently allowed the rotor RPM to decay during the takeoff climb. The aircraft's left skid contacting soft soil contributed to the forward pitch upon impact.

Probable cause

The pilot inadvertently allowed the rotor RPM to decay.

Frequently asked questions

What happened in the 1 Aug 1984 Bell 47G-5A accident near Winterhaven, CA?

After loading with 60 gallons of pesticide, a pilot began takeoff. The aircraft became airborne, traveled about 300 feet, then rotor RPM decayed, causing descent. The left skid dug into soft soil, pitching the aircraft forward; it came to rest upright.

What aircraft was involved and where did it happen?

The accident on 1 Aug 1984 involved a Bell 47G-5A, registration N4099G, at Winterhaven, CA.

What was the probable cause of the accident?

The pilot inadvertently allowed the rotor RPM to decay.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001214X40757. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.