Grimm RV-9A N629BJ

Summary

On 20 March 2012 at about 22:30 local time, a Grimm RV-9A registered N629BJ, operated by Grimm William H, was involved in an accident near Santa Maria, California, United States. 2 people were on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

20 March 2012 at 22:30

Classification

Accident

Location

Santa Maria, California, United States

Nearest airport

Santa Maria (SMX)

Coordinates

34.8850, -120.3931

Aircraft

Grimm RV-9A

Registration

N629BJ

Category

Airplane

Engines

1

Operator

Grimm William H

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Oceano → Santa Maria

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR12LA141

Nobody was injured.

A partial loss of engine power during cruise flight for reasons that could not be determined because postaccident examination and testing did not reveal any anomalies that would have precluded normal operation.

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

Read the full NTSB narrative

After the pilot leveled the experimental amateur-built airplane for cruise flight, the engine began to vibrate and lose power. He immediately applied full rich fuel mixture, then conducted a series of troubleshooting procedures, including recycling power to the electronic ignition system and switching between the left and right electronic magneto. The vibration continued with no increase in engine performance, and, unable to maintain altitude, he performed a forced landing into a plowed field, where the airplane sustained substantial damage. Subsequent examination of the engine revealed no anomalies that would have precluded normal operation. The ignition modules were examined and tested, and, while one unit exhibited wear consistent with imminent failure, both units functioned correctly. If one of the ignition units had failed in flight and lost its timing reference, it could have resulted in the observed engine vibration. However, if this was the case, the troubleshooting steps performed by the pilot would have remedied the problem. During examination, compression was not attained for one of the engine cylinders. This was most likely due to postaccident cylinder contamination and did not cause the loss of engine power.

Quoted verbatim from the NTSB record.