Eurocopter AS 350 B3 accident near Troutdale, Oregon, July 27, 2011
On July 27, 2011 at about 10:40 pm local time, a Eurocopter AS 350 B3 (helicopter), registered N808LF, was substantially damaged in an accident during enroute near Troutdale, Oregon (Portland-Troutdale airport). It was a positioning flight under general aviation rules (Part 91). No one was hurt; 4 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The in-flight separation of the tail rotor drive shaft cover as a result of maintenance personnel not ensuring that it was secured after a maintenance inspection; also causal was the pilot’s inadequate preflight inspection of the helicopter.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 27, 2011 · about 10:40 pm local time
- Place
- Troutdale, Oregon · Portland-Troutdale · map
- Type
- Accident
- Injuries
- No one was hurt; 4 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Eurocopter AS 350 B3 · all AS 350 B3s on the register
- Registration
- N808LF · registry record · serial 4983
- Damage
- Substantial damage
- Flight
- Positioning flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot reported that, about 12 minutes into a repositioning flight following a maintenance task performed by a company mechanic, he felt something that he described as similar to a bird strike. The pilot subsequently elected to make a precautionary landing in order to assess the situation. During an examination of the helicopter after the uneventful landing, the pilot discovered that a portion of the tail rotor drive shaft cover was missing and that one main rotor blade and two tail rotor blades had been damaged. Postaccident discussions with the company’s director of maintenance determined that the maintenance staff (who had recently performed a maintenance inspection) and the pilot likely looked at the tail rotor drive shaft cover prior to the accident flight and presumed that it was secure or had been secured by someone else; however, it was not secure and came off during flight. Following the accident, the company implemented a primary mechanic position into its Field Mechanic Procedures in order to mitigate a similar occurrence.
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
- Aircraft maintenance event during prior to flight
- Aircraft inspection event during prior to flight
- Part(s) separation from AC during enroute defining event
The NTSB's findings
- cause Personnel issues › Task performance › Maintenance › Scheduled/routine maintenance › Maintenance personnel
- cause Personnel issues › Task performance › Inspection › Preflight inspection › Pilot
- cause Aircraft › Aircraft structures › Fuselage › Aerodynamic fairings structure › Incorrect service/maintenance
- cause Personnel issues › Action/decision › Action › Lack of action › Maintenance personnel
Pilot
- Certificate: commercial pilot
- Ratings: instructor: helicopter; instructor: instrument helicopter; instrument: helicopter; rotorcraft: helicopter
- Flight time: 2,650 hours in all; 339 in this make and model; 47 in the last 90 days; 18 in the last 30 days; 2,600 as pilot in command
- Last flight review: January 24, 2011
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: rgt
- Injury: no injuries
The aircraft
- Airframe total time: 282 hours
- Last inspection: approved inspection programme, July 27, 2011; 0 hours since
- Maximum gross weight: 5,225 lb
- Seats: 5
- Landing gear: fixed
- Engine: Turbomeca Arriel 2B1 (turboshaft); 0 hours total
- Operator: Air Methods
The flight
- Departed from: UAO Aurora OR at 10:28 pm
- Destination: DLS Dallesport WA
Weather at the time
- Light: daylight
- Wind: at 5 knots
- Visibility: 10 statute miles
- Sky: a few clouds at 4,800 ft
- Temperature: 75°F (24°C), dew point 52°F (11°C)
- Altimeter: 30.09 inHg
- Observation at 10:53 pm from TTD
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 3 |
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.
Other NTSB records under N808LF the same tail number, which may have belonged to a different aircraft at the time
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.