Aerospatiale AS350D accident near Volcano, Hawaii, August 19, 1989
On August 19, 1989 at about 7:10 pm local time, a Aerospatiale AS350D (helicopter), registered N35970, was destroyed in an accident near Volcano, Hawaii. It was a flight of an unrecorded kind under charter and air-taxi rules (Part 135). 1 person was seriously injured and 5 people had minor injuries; 1 other was unhurt. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A CATASTROPHIC FAILURE OF THE POWER TURBINE SHAFT AND BEARINGS. THE FAILURE WAS A RESULT OF OIL STARVATION DUE TO AN EXCESSIVELY WORN CHIP DETECTOR O-RING SEAL,INADEQUATE MAINTENANCE AND PREFLIGHT. CONTRIBUTING FACTOR(S) WAS: THE MOUNTAINOUS TERRAIN.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 19, 1989 · about 7:10 pm local time
- Place
- Volcano, Hawaii · map
- Type
- Accident
- Injuries
- 1 person was seriously injured and 5 people had minor injuries; 1 other was unhurt.
- Weather
- visual conditions (good weather)
- Aircraft
- Aerospatiale AS350D · all AS350Ds on the register
- Registration
- N35970 · no longer on the register · serial 1131
- Damage
- Destroyed
- Flight
- Flight of an unrecorded kind · charter and air-taxi rules (Part 135)
The NTSB's narrative final · quoted from the NTSB record
THE VFR SIGHT-SEEING FLIGHT WAS BEING CONDUCTED UNER 14 CFR 135. WHILE DESCENDING INTO A MOUNTAINOUS AREA THE PILOT FELT A SEVERE VIBRATION ABT 10 - 15 SECONDS BEFORE THE ENGINE FAILED. THE PLT EXECUTED AN AUTOROTATION IN THE UPWARD SLOPING TERRAIN AND THE HELICOPTER ROLLED-OVER ON TOUCHDOWN. THE ENGINE EXAM DSCLSD THAT THE POWER TURBINE SHAFT AND THE NOS. 2 & 3 BEARINGS FAILED DUE TO OIL STARVATION AND DISPLAYED EXTREME HIGH TEMPERATURE DISTRESS. THE CHIP DETECTOR O-RING SEAL WAS EXCESSIVELY WORN. OIL RESIDUE STREAKING WAS FOUND ON THE OUTSIDE OF THE FUSELAGE/ TAILCONE ASSY AND THE VERTICAL/HORIZONTAL STABILIZERS.
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: 8,000 hours in all; 20 in this make and model; 250 in the last 90 days; 100 in the last 30 days; 7,500 as pilot in command
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 8,833 hours
- Last inspection: 100-hour inspection, August 8, 1989; 68 hours since
- Maximum gross weight: 4,300 lb
- Seats: 7
- Landing gear: fixed
- Engine: Lycoming LTS-101 (turboshaft); 0 hours total
- Operator: Papillon Helicopters, LTD
The flight
- Departed from: Waikoloa HI at 6:40 pm
- Runway 0
Weather at the time
- Light: daylight
- Visibility: 15 statute miles
- Sky: clear
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 5 | 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.