NTSB Identification: LAX05FA271.
The docket is stored in the Docket Management System (DMS). Please contact Records Management Division
Accident occurred Wednesday, August 17, 2005 in Pomona, CA
Probable Cause Approval Date: 09/14/2007
Aircraft: Piper PA-24-250, registration: N7342P
Injuries: 2 Fatal,1 Serious.

NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this aircraft accident report.

While on approach for the destination airport, the pilot reported engine problems, and attempted to land in a field short of the airport. During the forced landing, the left wing contacted the ground, and the airplane tumbled through an impact sequence. During the postaccident engine examination, investigators noted debris and corrosion inside the carburetor and the main jet passage. The airframe and engine inspection revealed no further mechanical anomalies that would have precluded normal operation. A Safety Board metallurgist examined the carburetor and debris/particles. The examination identified that the debris/particles were most likely a combination of lead and soil that had built up over time. The corrosion indicated prolonged exposure to water. The particles probably caused a restricted flow of air-fuel mixture in the main jet that eventually resulted in a reduction or loss of engine power once the particulate contamination had built up to a significant amount. There were no entries in either the airframe or engine logbook indicating that the carburetor had ever been overhauled in its 46-year history. The carburetor manufacturer issued a service bulletin regarding the overhaul of the accident airplanes' carburetor. The recommended time for the overhaul was either at the engine manufacturer's time between overhaul, or every 10 years the carburetor was in service, whichever came first. While service bulletins are not mandatory, had the carburetor been inspected at the manufacturer's recommended intervals, the corrosion and debris may have been identified and source of the fuel system contamination corrected. Investigators noted that the airplane had not been equipped with a shoulder harness restraint system. The fatal injuries for the pilot and front seat passenger were caused by head and upper torso trauma associated with the upper body not being restrained during the impact sequence. The airplane manufacturer had issued Service Bulletin No. 980, Shoulder Harness Installation, in 1995, for the accident make and model airplane. The pilot/owner had purchased the shoulder harness restraint system kit for his airplane, but had not installed them. The still packaged shoulder harnesses were found in the debris field by the investigation team.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

A loss of engine power during the landing approach due to fuel starvation caused by debris and corrosion in the carburetor assembly. A factor contributing to the accident was the failure of the owner to comply with the manufacturer's service bulletin regarding overhaul of the carburetor.

Full narrative available

Index for Aug2005 | Index of months