Accident Overview
On August 17, 2018, at about 1320 eastern daylight time, a Beech N35, registration N1330Z, sustained substantial damage when it was ditched into the Atlantic Ocean near Mayport, Florida. The pilot, the sole occupant, was not injured. The flight was operated as a personal flight under Title 14 Code of Federal Regulations Part 91.
Flight History
The airplane departed Rutherford County Airport (FQD) in Rutherfordton, North Carolina, about 0930, destined for Ormond Beach Municipal Airport (OMN) in Ormond Beach, Florida. The pilot reported cruising at an altitude of 4,500 ft when the engine lost total power. Attempts to restart the engine were unsuccessful. The pilot contacted air traffic control and was advised that Mayport Naval Station (NRB) was the nearest airport. The pilot stated he could not reach the airport and ditched about 3 miles east of NRB. The crew of a nearby ship rescued the pilot.
Postaccident Examination
After recovery, examination revealed that both elevators had separated from the horizontal stabilizers. Due to immersion in saltwater, the continuity of the engine's valvetrain and powertrain could not be established. Visual inspection of the engine found a broken fuel line attached to the fuel flow sensor. The fuel flow sensor and broken fuel line were sent to the National Transportation Safety Board Materials Laboratory for further examination.
Fuel Line Fracture Analysis
The fracture surfaces on the broken fuel line exhibited features consistent with high-stress, low-cycle fatigue crack propagation. The crack initiated on the outside surface, progressed through the thickness of the aluminum fuel line, and extended partially along its circumference until final overstress fracture.
Installation Review
A review of installation drawings and instructions indicated that the fuel flow sensor was installed without a mounting bracket per Insight drawing 1000-303 (bracket type 3). This configuration uses a metal plumbing fitting for support directly to the engine fuel distributor. Alternate approved mounting methods are described in drawings 1000-303 (bracket type 1), which attaches the sensor to the engine top case bolts using flexible hoses, and type 2, which attaches to the firewall also with flexible hoses. The Insight Avionics installation manual states that the installing mechanic should determine the best mounting type, as all three are approved.
Maintenance Records
A review of the maintenance logbook revealed no record of the fuel flow sensor installation. However, an Insight G-2 installation record dated January 18, 2016, indicated that the Insight G-2 engine monitor was installed with only six exhaust gas and six cylinder head temperature probes.