American AA-5 N65KS accident near Fort Pierce, Florida

Probable cause

A loss of engine power due to fuel starvation as a result the failure of the engine fuel pump diaphragms during climb.

NTSB analysis

The pilot stated that he was climbing to 2,500 feet mean sea level when he felt a vibration. The engine rpm dropped from 2,400 rpm to 1,800 rpm, and then the engine appeared to be "wind milling." He initiated a forced landing to an open field, and the airplane collided with a landscaping trailer, causing structural damage to the airplane. Examination of the airframe and flight controls revealed no anomalies. The engine assembly was transported to an authorized repair facility for an engine run. Temporary repairs were made to leads and the engine fuel pump was bypassed due to damage from the collision with the trailer. The engine started and the power was increased to 1500 rpm. The power was not increased any further due to a bent propeller flange. The engine was stabilized and shut down. The fuel pump was removed from the engine and disassembled. The aircraft component list revealed the last fuel pump was installed in 1973. No other information was available on the fuel pump due to an engine swap. Examination of the fuel pump diaphragms revealed they were very hard and holes were present in the diaphragms.

Text from the NTSB. Open the NTSB docket for ERA09LA420 for the full record.