Aerospatiale AS-350D accident near Hilo, Hawaii, October 14, 1991
On October 14, 1991 at about 8:25 pm local time, a Aerospatiale AS-350D (helicopter), registered N35961, was substantially damaged in an accident near Hilo, Hawaii. It was a flight of an unrecorded kind under charter and air-taxi rules (Part 135). No one was hurt; 7 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
1) A LOSS OF ENGINE POWER DUE TO THE INGESTION OF GASSES FROM THE ACTIVE VOLCANO VENT, AND 2) THE PILOTS INFLIGHT DECISION TO HOVER DOWNWIND IN CLOSE PROXIMITY TO THE VENT.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- October 14, 1991 · about 8:25 pm local time
- Place
- Hilo, Hawaii · map
- Type
- Accident
- Injuries
- No one was hurt; 7 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Aerospatiale AS-350D · all AS-350Ds on the register
- Registration
- N35961 · no longer on the register · serial 1113
- 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 HELICOPTER WAS HOVERING NEAR THE EDGE OF THE VOLCANICALLY ACTIVE CRATER AT 15 TO 20 FEET ABOVE GROUND LEVEL. THE HELICOPTER WAS HOVERING DOWNWIND OF THE VENT. SEVERAL LOUD POPPING SOUNDS WERE HEARD COMING FROM THE ENGINE AND THE PILOT SENSED A LOSS OF POWER. THE PILOT AUTO ROTATED TO A DOWN SLOPE HARD LANDING AND THE MAIN ROTOR CONTACTED THE TAIL BOOM. AFTER RECOVERY FROM THE ACCIDENT SITE, THE ENGINE WAS EXAMINED WHILE STILL IN PLACE IN THE HELICOPTER. FUEL SAMPLES WERE REMOVED FROM THE TANK AND SUMP, AND FOUND TO BE CLEAR. ALL PC AIR LINES WERE PRESSURE CHECKED, WITH A SMALL LEAK DETECTED ON THE INLET SIDE OF THE PC FILTER. THE ENGINE WAS STARTED AND TEST RUN IN THE AIRFRAME UP TO 72% N1, WITH NO ADVERSE FINDINGS. THE ENGINE WAS REMOVED FROM THE HELICOPTER AND SHIPPED TO THE LYCOMING FACTORY WHERE IT WAS INSTALLED IN A TEST CELL. THE ENGINE WAS RUN FOR 50 MINUTES, TO INCLUDE AN ACCELERATION TEST. THE ENGINE DEVELOPED AND SUSTAINED FULL POWER IN ACCORDANCE WITH THE AEROSPATIALLE AS-350D AIRFRAME APPLICATION. NO MALFUNCTIONS OR DEFECTS WERE NOTED.
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: airplane single-engine; instructor: helicopter; instrument: airplane; rotorcraft: helicopter
- Flight time: 2,362 hours in all; 94 in this make and model; 143 in the last 90 days; 94 in the last 30 days; 2,266 as pilot in command; 1,529 on instruments
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 5,292 hours
- Last inspection: continuous airworthiness programme, September 27, 1991; 57 hours since
- Maximum gross weight: 4,300 lb
- Seats: 7
- Landing gear: fixed
- Engine: Lycoming LTS-101-600 (turboshaft); 0 hours total
The flight
- Departed from: HI07 Waikoloa HI at 7:40 pm
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 185° at 15 knots
- Visibility: 15 statute miles
- Sky: clear
- Temperature: 73°F (23°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 6 |
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.