Cessna TU206F N62DB accident near Glendale, Arizona

Probable cause

A loose fuel line fitting that resulted in a partial loss of engine power during the initial takeoff climb. Contributing to the accident was inadequate maintenance installation of the fitting.

NTSB analysis

The pilot reported that the engine began to run rough shortly after takeoff. Unable to return to the airport, he initiated a forced landing in a short field. The airplane collided with a fence during the landing roll. During a post crash examination, a loose fuel line fitting was discovered that was connected to the fuel flow transducer inlet. It was also noted that there were blue stains on the crankcase immediately below the fitting. After tightening the fitting, the engine started and ran smoothly at 1,800 revolutions per minute (rpm) with a smooth rpm drop for each magneto. The fitting was then manually loosened again with the engine running at 1,800 rpm, the fuel pressure fell below the bottom of the green arc, and the engine began to run rough. The fitting was again tightened, and smooth engine operation resumed. The last maintenance recorded that would have involved removal of this fitting was during an engine replacement on July 7, 2007, which was 127 hours prior to the accident.

Text from the NTSB. Open the NTSB docket for LAX08LA269 for the full record.