Aerospatiale AS35OD accident near Theriot, Louisiana, June 16, 1986
On June 16, 1986 at about 1:45 pm local time, a Aerospatiale AS35OD (helicopter), registered N229EH, was substantially damaged in an accident near Theriot, Louisiana. It was a flight of an unrecorded kind under charter and air-taxi rules (Part 135). 1 person was seriously injured. 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
- June 16, 1986 · about 1:45 pm local time
- Place
- Theriot, Louisiana · map
- Type
- Accident
- Injuries
- 1 person was seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Aerospatiale AS35OD
- Registration
- N229EH · no longer on the register · serial 1227
- Damage
- Substantial damage
- Flight
- Flight of an unrecorded kind · charter and air-taxi rules (Part 135)
The NTSB's narrative final · quoted from the NTSB record
THE PILOT EXPERIENCED A SUDDEN YAW IN THE HELICOPTER AT CRUISE FLIGHT. THE NG STARTED WINDING DOWN CONFIRMING AN ENGINE FAILURE. THE PILOT HAD TO EXTEND AN AUTOROTATION OVER A TREE LINE, WHICH CAUSED THE RPM TO DECREASE, AND MADE A HARD LANDING IN AN ADJACENT FIELD. DAMAGE TO THE HELICOPTER INCLUDED THE TAIL SECTION, LANDING GEAR AND MAIN ROTOR. INSPECTION OF THE ENGINE REVEALED THAT BOTH THE GEAR SPUR COMPRESOR SHAFT AND THE GEAR SPUR ACCESSORY DRIVE WERE MISSING TEETH. THE INSPECTION ALSO REVEALED THAT METAL FRAGMENTS FROM THE GEARS WERE DISTRIBUTED THROUGHOUT THE ENGINE'S LUBRICATION SYSTEM.
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: single-engine land; rotorcraft: helicopter
- Flight time: 7,893 hours in all; 576 in this make and model; 77 in the last 90 days; 7,833 as pilot in command
- Medical certificate: Class 1 (valid medical--w/ waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 2,278 hours
- Last inspection: 100-hour inspection, June 13, 1986; 11 hours since
- Maximum gross weight: 4,188 lb
- Seats: 6
- Landing gear: fixed
- Engine: Lycoming LTS101600A-2 (turboshaft); 0 hours total
The flight
- Departed from: HUM Houma LA at 1:40 pm
- Flight plan: VFR
- Runway 0
Weather at the time
- Light: daylight
- Visibility: 7 statute miles
- Sky: scat at 30,000 ft
- Temperature: 81°F (27°C), dew point 64°F (18°C)
- Altimeter: 30.00 inHg
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.