Bell 47G-2 accident near Spring Brook, Wisconsin, August 31, 2000
On August 31, 2000 at about 2:30 pm local time, a Bell 47G-2 (helicopter), registered N67083, was substantially damaged in an accident near Spring Brook, Wisconsin. 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 fatigue failure of the tail rotor drive gear shaft.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 31, 2000 · about 2:30 pm local time
- Place
- Spring Brook, Wisconsin · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell 47G-2 · all 47G-2s on the register
- Registration
- N67083 · no longer on the register · serial 2280
- 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 helicopter impacted the terrain following a loss of tail rotor effectiveness. The pilot reported he just completed a turn in order to begin a swath run when he experienced a loss of tail rotor effectiveness. He attempted to control the helicopter, however it continued to rotate until it impacted the terrain in a clearing in a wooded area. Post accident examination revealed a failure of the tail rotor drive gear assembly. The drive gear shaft was fractured at the underside of the bevel gear. Metallurgical examination revealed fatigue was found over 90 to 95 percent of the shaft cross sectional area. The fatigue cracking origin was on the cylindrical portion of the shaft surface, adjacent to the keyway slot.
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: commercial pilot
- Ratings: multi-engine land; single-engine land; instrument: airplane; rotorcraft: helicopter
- Flight time: 820 hours in all; 400 in this make and model; 450 in the last 90 days; 148 in the last 30 days; 756 as pilot in command
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: frt
The aircraft
- Airframe total time: 5,558 hours
- Last inspection: 100-hour inspection, August 20, 2000; 117 hours since
- Maximum gross weight: 2,850 lb
- Seats: 1
- Landing gear: fixed
- Engine: Lycoming O-435-A1F HC (piston); 0 hours total
The flight
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 190° at 3 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 68°F (20°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.
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.