Eurocopter AS350B2 accident near Pacoima, California, November 12, 2010
On November 12, 2010 at about 3:48 pm local time, a 2003 Eurocopter AS350B2 (helicopter), registered N1231A, was substantially damaged in an accident during initial climb near Pacoima, California (Whiteman Field). It was an aerial observation flight under general aviation rules (Part 91). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The contamination of a spool bearing in the power turbine governor during manufacture, which led to the bearing’s failure in flight, a subsequent loss of engine power during departure, and the resultant hard landing.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- November 12, 2010 · about 3:48 pm local time
- Place
- Pacoima, California · Whiteman Field · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Eurocopter AS350B2, built 2003 · all AS350B2s on the register
- Registration
- N1231A · registry record · serial 3682
- Damage
- Substantial damage
- Flight
- Aerial observation flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
During a downwind departure from the airport, the engine began to lose power. The pilot initiated an immediate autorotation back toward the airport while adjusting the airspeed and flight controls to clear power lines along the airport boundary. After clearing the power lines, the helicopter settled hard on the runway centerline and then began to rock, slide, and yaw right. The pilot attempted to regain control of the helicopter, and it eventually came to a stop upright on its skids facing about 160 degrees right of the runway centerline. The aft portion of the tail boom had separated. Postaccident testing and examination of the engine revealed a degraded power turbine (PT) governor spool bearing. Examinations also revealed the presence of diamond particles, which are used in the manufacturing process for the ball bearings, in the governor spool bearing. It is likely that diamond particle contamination caused the governor spool bearing to fail, which rendered the PT governor incapable of modulating governor servo pressure to the fuel control unit. Although no physical evidence was found indicating that the electronic overspeed system activated, the pilot's statement about two increases in rpm and then a decrease in rpm indicates that the system likely activated. The loss of PT governing ability coupled with the activation of the electronic overspeed system likely resulted in fuel flow oscillations that decreased the fuel flow below the lean blowout limit of the engine and led to the loss of engine power.
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
What happened, in order
- Loss of engine power (partial) during initial climb defining event
- Hard landing during landing (flare/touchdown)
The NTSB's findings
- cause Aircraft › Aircraft power plant › Engine (turbine/turboprop) › Turbine section › Damaged/degraded
- cause Aircraft › Aircraft power plant › Engine fuel and control › Turbine governor › Damaged/degraded
- Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Descent rate › Attain/maintain not possible
- Personnel issues › Task performance › Maintenance › (general) › Not specified
- cause Organizational issues › Development › Manufacture/production › (general) › Manufacturer
Pilot
- Certificate: airline transport pilot, flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; single-engine sea; instructor: airplane multi-engine; instructor: airplane single-engine; instrument: airplane; instrument: helicopter; rotorcraft: helicopter
- Flight time: 10,500 hours in all; 7,300 in this make and model
- Last flight review: August 22, 2010
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: rgt
- Injury: no injuries
The aircraft
- Airframe total time: 3,456 hours
- Last inspection: 100-hour inspection, October 5, 2010
- Maximum gross weight: 4,961 lb
- Seats: 6
- Landing gear: fixed
- Engine: Honeywell LTS101-700-D2 (turboshaft); 4,042 hours total
- Operator: Tiny Bubbles, Inc.
The flight
- Departed from: WHP Pacoima CA at 3:47 pm
- Destination: WHP Pacoima CA
- Flight plan: none
- Runway 30, 4,120 ft by 75 ft
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 57°F (14°C), dew point 25°F (-4°C)
- Altimeter: 30.32 inHg
- Observation at 3:53 pm from KBUR
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 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.