Bell 47-G3B1 accident near Winterhaven, California, February 10, 2001
On February 10, 2001 at about 3:00 am local time, a Bell 47-G3B1 (helicopter), registered N3084G, was substantially damaged in an accident near Winterhaven, California. It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A failure of the transmission free wheeling unit due to improper maintenance. A factor was the dark night visual condition.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- February 10, 2001 · about 3:00 am local time
- Place
- Winterhaven, California · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell 47-G3B1 · all 47-G3B1s on the register
- Registration
- N3084G · no longer on the register · serial 2916
- Damage
- Substantial damage
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
The pilot was applying chemicals at night to a field of lettuce and had just taken off from his truck platform with 60 gallons of chemicals. He was about 20 feet above ground level and had a forward air speed of approximately 30 miles per hour when he heard a loud screeching sound, followed by a yaw to the left, a rapid decay of rotor rpm, and an increase/overspeed in engine rpm. The helicopter landed hard, collapsing the skids. Post accident examination of the transmission was conducted, revealing that the outer surface of the free wheeling unit of the inner gear assembly was worn below allowable limits at the roller/gear operating surface. The worn freewheeling inner ring gear allowed a mechanical disconnect between the engine output and the main rotor transmission, and resulted in a loss of main rotor speed and the subsequent hard landing.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
Pilot
- Certificate: flight instructor, commercial pilot
- Ratings: single-engine land; instructor: helicopter; instrument: airplane; instrument: helicopter; rotorcraft: helicopter
- Flight time: 18,930 hours in all; 2,500 in this make and model; 52 in the last 90 days; 29 in the last 30 days; 18,400 as pilot in command
- Last flight review: June 29, 2000
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 6,322 hours
- Last inspection: 100-hour inspection, November 27, 2000; 38 hours since
- Maximum gross weight: 2,950 lb
- Seats: 3
- Landing gear: fixed
- Engine: Avco Lycoming TVO-435-B1A (piston); 0 hours total
The flight
- Departed from: NONE Yuma AZ at 1:55 am
- Flight plan: none
Weather at the time
- Light: night, dark
- Wind: from 030° at 1 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 50°F (10°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Other NTSB records under N3084G the same tail number, which may have belonged to a different aircraft at the time
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.