Eurocopter France EC130 B4 accident near Prairie Du Sac, Wisconsin, August 7, 2004
On August 7, 2004, a Eurocopter France EC130 B4 (helicopter), registered N450CM, was destroyed in an accident near Prairie Du Sac, Wisconsin. It was a personal flight under general aviation rules (Part 91). 2 people were killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot's intentional low-level flight toward the lake and his failure to maintain clearance from the static wire on power transmission lines. Contributing factors were the separation of the Fenestron (tail rotor) assembly from the tail boom as a result of the collision with the static wire and the subsequent loss of control.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 7, 2004
- Place
- Prairie Du Sac, Wisconsin · map
- Type
- Accident
- Injuries
- 2 people were killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Eurocopter France EC130 B4 · all EC130 B4s on the register
- Registration
- N450CM · registry record · serial 3774
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The helicopter was destroyed by impact forces and post crash fire after it collided with a static wire spanning a lake bay inlet about 80 feet above the surface of the water. The Fenestron (tail rotor) assembly separated from the tail boom when it struck the wire and the helicopter subsequently entered an uncontrolled descent. The main helicopter body impacted a single-family residence located near the shoreline and came to rest on the ground next to the home. The pilot and pilot-rated passenger sustained fatal injuries. One person in the residence sustained minor injuries. Witnesses at several locations along the flight path reported a low-flying helicopter matching the description of the accident aircraft. One witness noted that it was "very fast" and at or below the top of their 70-foot high silos. Two witnesses to the accident sequence reported that they were in a boat on the lake and that they saw the helicopter descend toward their position. One of them noted that the aircraft's flight path was "very direct" and that it was not "wavering." As the helicopter passed overhead, they recalled components coming off the aircraft. They both stated that when they looked back the power lines were "bouncing." A third witness reported that she saw the helicopter dip low toward the water and then come back up toward the power lines. She saw the tail separate from the helicopter and the aircraft went over trees on the opposite side of the lake from her position. The power company reported that power was automatically interrupted in the area at the time of the accident. Technicians dispatched to the site reported that one of the static wires was wrapped around a transmission line. A post accident inspection of the helicopter did not reveal any anomalies associated with a pre impact failure. The Fenestron fracture surface exhibited directional metal transfer features and transferred zinc consistent with impact with a galvanized steel static line.
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: multi-engine land; single-engine land; instrument: airplane; instrument: helicopter; rotorcraft: helicopter
- Flight time: 1,211 hours in all; 148 in this make and model; 154 in the last 90 days; 62 in the last 30 days; 870 as pilot in command
- Last flight review: February 19, 2004
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Injury: fatal
The aircraft
- Airframe total time: 202.6 hours
- Last inspection: annual inspection, June 29, 2004; 91.5 hours since
- Maximum gross weight: 5,291 lb
- Seats: 6
- Landing gear: fixed
- Engine: Turbomeca Arriel 2B1 (turboshaft); 0 hours total
- Fire on the ground
The flight
- Departed from: RST Rochester MN at 11:58 pm
- Destination: Milwaukee WI
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 230° at 3 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 72°F (22°C), dew point 54°F (12°C)
- Altimeter: 30.11 inHg
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| 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.