Bell 47J accident near Grove, Oklahoma, July 27, 1984
On July 27, 1984 at about 3:30 pm local time, a Bell 47J (helicopter), registered N2837B, was destroyed in an accident near Grove, Oklahoma. It was a personal flight under general aviation rules (Part 91). 1 person had minor injuries; 2 others were unhurt. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The NTSB has not yet published a probable cause for this accident. Investigations usually take one to two years; this page updates when the final report is released.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 27, 1984 · about 3:30 pm local time
- Place
- Grove, Oklahoma · map
- Type
- Accident
- Injuries
- 1 person had minor injuries; 2 others were unhurt.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell 47J · all 47Js on the register
- Registration
- N2837B · no longer on the register · serial 1720
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE PLT STATED THAT YAW CONTROL WAS LOST DURING CLIMB OUT FOR A LOCAL FLT WITH TWO PASSENGERS ONBOARD. THE ACFT BEGAN TOROTATE TO THE RIGHT AND THE ANTITORQUE PEDALS WERE INEFFECTIVE. THEY WERE OVER BUILDINGS AT THE TIME SO THE PLT HELD A MINIMUM DESCENT UNTIL CLEAR OF THE BUILDINGS. THE ACFT CONTINUED TO ROTATE UNTIL GROUND IMPACT. THE ACFT ROLLED OVER ON ITS RIGHT SIDE AND CAUGHT FIRE. INSPECTION OF THE ACFT REVEALED THAT BOTH PINS IN THE TAIL ROTOR DRIVE U-JOINT HAS SHEARED DUE TO UNSUFFICIENT TORQUE ON THE ACORN NUTS.
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: airline transport pilot, flight instructor
- Ratings: multi-engine land; single-engine land; single-engine sea; instructor: airplane multi-engine; instructor: airplane single-engine; instrument: airplane; instrument: helicopter; rotorcraft: helicopter
- Flight time: 7,580 hours in all; 400 in this make and model; 50 in the last 90 days; 7,400 as pilot in command
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: frt
The aircraft
- Airframe total time: 3,493 hours
- Last inspection: 100-hour inspection, April 12, 1984; 20 hours since
- Maximum gross weight: 2,565 lb
- Seats: 3
- Landing gear: fixed
- Engine: Lycoming VO-435-A1E (piston); 0 hours total
- Fire on the ground
The flight
- Departed from: Grove OK
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 010° at 9 knots
- Visibility: 10 statute miles
- Sky: scat at 4,000 ft
- Temperature: 81°F (27°C), dew point 68°F (20°C)
- Altimeter: 30.00 inHg
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 1 | 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.