Amateur-built HANSEN-VANS RV-6 accident near Lemolo Lake, Oregon, September 5, 2012
On September 5, 2012 at about 10:00 pm local time, a 2005 amateur-built HANSEN-VANS RV-6, registered N53MH, was substantially damaged in an accident during enroute (cruise) near Lemolo Lake, Oregon. It was an instructional flight under general aviation rules (Part 91). 1 person was seriously injured. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
An overvoltage event due to the failure of the automotive voltage regulator, which resulted in electrical anomalies and smoke in the cockpit and a subsequent forced off-airport landing.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 5, 2012 · about 10:00 pm local time
- Place
- Lemolo Lake, Oregon · map
- Type
- Accident
- Injuries
- 1 person was seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built HANSEN-VANS RV-6, built 2005
- Registration
- N53MH · registry record · serial MPH-3
- Damage
- Substantial damage
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The student pilot/owner of the experimental, amateur-built airplane was conducting a long cross-country solo flight, and he completed the first two legs uneventfully. He reported that, when the airplane was in cruise flight at 10,500 ft on the final leg of the trip, he began experiencing radio problems, followed shortly by other electrical problems and smoke in the cockpit. Due to concerns about an on-board fire, he opted to conduct a precautionary landing on a road. During the landing roll, the airplane exited the paved surface, nosed over, and then came to rest inverted. Postaccident examination of the airplane did not reveal any indications of smoke or thermal damage. However, four electrically powered devices, including the voltmeter, were found to be inoperative. Although a visual examination of the alternator, which was a 12-volt automotive-grade unit with an integral voltage regulator, found no evidence of electrical arcing or thermal damage, a functional check revealed that the continuous-regulated voltage output was greater than 18 volts. The alternator and regulator were disassembled, and no internal mechanical anomalies were identified. The electrical anomalies described by the pilot and noted during the tests and examinations, particularly the failed voltmeter, were consistent with an overvoltage event due to the failure of the automotive voltage regulator, which would have resulted in the smoke in the cockpit. Although the engine likely would have continued to run with the noted electrical system anomalies, the pilot had no way of knowing whether the observed smoke and electrical anomalies would result in additional problems or an onboard fire; therefore, his decision to conduct a forced landing was appropriate.
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
- Electrical system malf/failure during enroute (cruise) defining event
- Fire/smoke (non-impact) during emergency descent
- Loss of control on ground during landing (flare/touchdown)
- Nose over/nose down during landing (flare/touchdown)
The NTSB's findings
- cause Aircraft › Aircraft systems › Electrical power system › Alternator › generator drive sys › Malfunction
Pilot
- Certificate: student
- Flight time: 100 hours in all; 25 in this make and model; 25 in the last 90 days; 8 in the last 30 days
- Medical certificate: Class 3 (without waivers/limitations)
- Seat: left
- Injury: serious injuries
The aircraft
- Airframe total time: 193 hours
- Last inspection: condition inspection, June 6, 2012; 25 hours since
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming O-360 SERIES (piston); 2,257 hours total
The flight
- Departed from: S21 Sunriver OR at 10:30 pm
- Destination: MFR Medford OR
- Flight plan: VFR
Weather at the time
- Light: daylight
- Wind: from 310° at 8 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 93°F (34°C), dew point 39°F (4°C)
- Altimeter: 29.87 inHg
- Observation at 9:53 pm from MFR, 75 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight 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.