Boeing A75N1(PT17) N63555 accident near Palm Springs, California

Probable cause

Improper assembly of a fuel hose, which restricted the fuel supply to the carburetor and resulted in a loss of engine power during the initial climb after takeoff.

NTSB analysis

The airline transport pilot reported that, shortly after takeoff on the local sightseeing flight, the engine experienced a partial loss of power about 400 ft above ground level. The pilot initiated a turn back to the airport and subsequently landed hard on the runway, substantially damaging the airplane.

During the postaccident engine examination, an obstruction was found in one end of the fuel hose between the gascolator to the carburetor. The firesleeve on the hose was removed, which revealed that the hose entered the fitting at a slight angle that was not visible with the firesleeve in place. To facilitate further examination, the hose was cut close to the obstruction. The inner surface of the hose appeared cut and curled into the hose near the fitting, consistent with the improper assembly of the hose and fitting. It is likely that the curled piece of hose acted as a flapper valve that either restricted or cut off fuel flow to the carburetor. The high demand for fuel during takeoff depleted the supply of fuel in the carburetor and resulted in the loss of power. Although maintenance log entries indicated that the last replacement of the fuel hoses occurred 49 years before the accident, given the condition of the hoses, it is likely that a subsequent replacement was performed but not documented.

Text from the NTSB. Open the NTSB docket for WPR16LA078 for the full record.