Bell 206 B3 accident near Arroyo Grande, California, August 1, 1985
On August 1, 1985 at about 5:15 pm local time, a Bell 206 B3 (helicopter), registered N90328, was substantially damaged in an accident near Arroyo Grande, California. It was an other work-use flight under external-load helicopter rules (Part 133). No one was hurt; 1 person was on board or involved. 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
- August 1, 1985 · about 5:15 pm local time
- Place
- Arroyo Grande, California · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell 206 B3 · all 206 B3s on the register
- Registration
- N90328 · no longer on the register · serial 1853
- Damage
- Substantial damage
- Flight
- Other work-use flight · external-load helicopter rules (Part 133)
The NTSB's narrative final · quoted from the NTSB record
WHILE HOVERING AND SLINGING AN EXTERNAL LOAD OVER ROUGH TERRAIN THE ENG CHIP LIGHT ILLUMINATED. THE PLT IMMEDIATELY POSITIONED THE ACFT TO RELEASE THE LOAD AND THE ENG BEGAN MAKING A 'WHINING' NOISE. SEVERAL SECONDS LATER ALL ENG POWER WAS LOST. THE PLT AUTOROTATED TO A FIRM LANDING AND UPON TOUCHDOWN THE MAIN ROTOR BLADES FLEXED DOWNWARD AND SEVERED THE TAIL BOOM. EXAM OF THE ENG'S TURBINE COMPONENTS REVEALED THE PRESENCE OF A 'SLUDGE' MATERIAL IN THE SCAVENGE OIL LINE FROM THE NO. 8 BEARING AND ALSO THE PRESENCE OF A HEAVY BUILD UP OF CARBON ON THE ENGINE ROTOR 'PEASHOOTER' DRIVE SHAFT. THE ACCUMULATED MATERIAL CAUSED SHAFT RUB AND FAILURE OF THE POWER TURBINE'S INNER SHAFT. THE OPERATOR REPORTED THAT AN EARLY INSPECTION OF THE N1/N2 DRIVE SHAFT AREA COULD HAVE DETECTED THE PROBLEM AND PREVENTED THE ACCIDENT.
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; instrument: helicopter; rotorcraft: helicopter
- Flight time: 5,959 hours in all; 1,600 in this make and model; 170 in the last 90 days
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 4,096 hours
- Last inspection: inspection type not recorded
- Maximum gross weight: 3,200 lb
- Seats: 5
- Landing gear: fixed
- Engine: Allison 250 SER 400HP (turboshaft); 0 hours total
The flight
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 225° at 15 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 64°F (18°C), dew point 0°F (-18°C)
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.