Hansen HANSEN-VANS RV-6 N53MH

Summary

On 5 September 2012 at about 22:00 local time, a Hansen HANSEN-VANS RV-6 registered N53MH was involved in an accident near Lemolo Lake, Oregon, United States. One person was on board and one was seriously injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

5 September 2012 at 22:00

Classification

Accident

Location

Lemolo Lake, Oregon, United States

Coordinates

43.3031, -122.1833

Aircraft

Hansen HANSEN-VANS RV-6

Registration

N53MH

Category

Airplane

Year built

2005

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Instructional

Phase of flight

Not recorded

Route

Sunriver → Medford

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR12LA402

1 person was seriously injured.

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.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

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.

Quoted verbatim from the NTSB record.