Beech 35 N1330Z accident near Mayport, Florida

Probable cause

The failure of a fuel line due to improper installation of a fuel flow sensor, which resulted in fuel starvation and a subsequent total loss of engine power.

NTSB analysis

The pilot reported that he was in cruise flight when the engine lost total power. The pilot's attempts to restart the engine were unsuccessful. He contacted air traffic control and reported that he was unable to make it to the closest airport and ditched the airplane into the Atlantic Ocean. Postaccident examination of the airplane revealed that both elevators had separated from the horizontal stabilizer during the ditching. Examination of the engine revealed that a fuel line that had been attached to the fuel flow sensor was broken. Detailed examination of the fracture surfaces on the broken fuel line fitting revealed features that were consistent with high-stress, low-cycle fatigue crack propagation. The crack initiated at the outside, progressing through the thickness of the aluminum fuel line and partially along its circumference until final overstress fracture. A review of the installation drawings and instructions revealed that the fuel flow sensor was installed without a mounting bracket per installation instructions. Given this information, it is likely that the fuel line fractured in fatigue due to the improper installation, and lack of support that would have been provided by the required bracket. The failure of the fuel line subsequently resulted in fuel starvation, and the total loss of engine power. While the available maintenance records detailed the installation of an engine monitoring device and accompanying cylinder head temperature probes, there were no records that indicated when the fuel flow sensor was installed.

Text from the NTSB. Open the NTSB docket for ERA18LA227 for the full record.