Eurocopter France EC120B accident near Fair Oaks, California, July 14, 2005
On July 14, 2005 at about 2:10 am local time, a Eurocopter France EC120B (helicopter), registered N266SD, was destroyed in an accident near Fair Oaks, California. It was a public-use flight (local) under public-use (government) rules. 2 people were killed and 1 person was seriously injured. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The failure of the constant delta P diaphragm in the fuel control unit, which resulted in an increased fuel flow and subsequent catastrophic failure of the engine. The diaphragm's failure was the result of improper installation by the engine manufacturer. A factor in the accident was the unsuitable nature of the terrain for a successful autorotation.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 14, 2005 · about 2:10 am local time
- Place
- Fair Oaks, California · map
- Type
- Accident
- Injuries
- 2 people were killed and 1 person was seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Eurocopter France EC120B · all EC120Bs on the register
- Registration
- N266SD · registry record · serial 1133
- Damage
- Destroyed
- Flight
- Public-use flight (local) · public-use (government) rules
The NTSB's narrative final · quoted from the NTSB record
The engine experienced an overspeed and catastrophic failure on a law enforcement patrol flight and the helicopter collided with hilly terrain during a subsequent autorotation attempt. Witnesses reported the helicopter began emitting smoke and subsequently descended, impacting terrain near the bottom of a 60-degree sloped hillside. The terrain around the accident site was either steeply sloped hillside with mature trees or bordered by power lines. A post accident examination of the engine and components revealed the constant delta P diaphragm (located in the fuel control unit) had ruptured, resulting in a high and uncontrolled increase of fuel flow to the engine. The power turbine exhibited evidence of a substantial overspeed. All of the turbine blades were separated at their respective shear points. The gas generator turbine exhibited evidence of extreme thermal erosion; the blades were eroded to about 50 percent of their normal height. The centrifugal compressor exhibited evidence of extreme rubbing. A detailed examination of the diaphragm revealed that it had been installed incorrectly (inside-out). The maintenance and engine manufacturer's build records revealed that the diaphragm was last replaced at the engine manufacturer's facilities in France. Recovered Vehicle and Engine Multifunctional Display (VEMD) information supported the evidence of an engine and main rotor revolutions per minute (rpm) exceedance.
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: rotorcraft: helicopter
- Flight time: 743 hours in all; 650 in this make and model; 110 in the last 90 days; 33 in the last 30 days; 629 as pilot in command
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: rgt
- Injury: fatal
The aircraft
- Airframe total time: 2,562.3 hours
- Last inspection: 100-hour inspection, July 1, 2005; 62.3 hours since
- Maximum gross weight: 3,780 lb
- Seats: 5
- Landing gear: fixed
- Engine: Turbomeca Arrius 2F (turboshaft); 0 hours total
The flight
- Departed from: KMHR Mather CA at 1:15 am
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 250° at 6 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 102°F (39°C), dew point 57°F (14°C)
- Altimeter: 29.78 inHg
- Observation at 1:45 am from KMHR, 7 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 1 | 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.