Bell 47-D1 accident near Sun, Louisiana, May 26, 1991
On May 26, 1991 at about 10:00 pm local time, a Bell 47-D1 (helicopter), registered N339MC, was substantially damaged in an accident near Sun, Louisiana. It was an aerial observation flight under general aviation rules (Part 91). No one was hurt; 3 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
THE TOTAL LOSS OF POWER FOR UNDETERMINED REASONS AND THE FAILURE OF THE PILOT TO MAINTAIN ROTOR RPM. A FACTOR WAS THE LACK OF SUITABLE TERRAIN.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- May 26, 1991 · about 10:00 pm local time
- Place
- Sun, Louisiana · map
- Type
- Accident
- Injuries
- No one was hurt; 3 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell 47-D1 · all 47-D1s on the register
- Registration
- N339MC · registry record · serial T121
- Damage
- Substantial damage
- Flight
- Aerial observation flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE PILOT HAD JUST DEPARTED A LOCAL FAIR GROUNDS WITH TWO PAYING PASSENGERS ON BOARD. AT APPROXIMATELY 300 FEET, A TOTAL LOSS OF ENGINE POWER WAS EXPERIENCED. THE PILOT INITIATED A 180 DEGREE AUTOROTATION IN ORDER TO CLEAR THE POPULATED AREA. THE AVAILABLE TERRAIN FOR LANDING WAS NOT LEVEL. DURING THE TOUCHDOWN, ROTOR RPM DECREASED DUE TO THE DIFFICULTY OF CONDUCTING A SLOPE LANDING. THE MAIN ROTOR BLADES SEVERED THE TAILBOOM OF THE HELICOPTER
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; rotorcraft: helicopter
- Flight time: 3,230 hours in all; 397 in this make and model; 112 in the last 90 days; 49 in the last 30 days; 3,044 as pilot in command; 1,417 on instruments
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 5,468 hours
- Last inspection: 100-hour inspection, May 6, 1991; 21 hours since
- Maximum gross weight: 2,350 lb
- Seats: 3
- Landing gear: fixed
- Engine: Franklin 6V335A (piston); 0 hours total
- Operator: Cook Aviation, INC.
The flight
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: broken clouds at 2,500 ft; scat
- Temperature: 81°F (27°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 2 |
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.