What happened
On July 13, 2008, an EMB 720D aircraft, registration PT-RZV, was performing a VFR passenger transport flight from Canarana to Confresa, Mato Grosso. Approximately two hours and 40 minutes into the flight, while cruising at 7,500 feet, the engine experienced a progressive loss of power. The pilot immediately identified indications of dropping fuel flow and pressure.
Following established emergency procedures, the pilot attempted to switch fuel tanks, activate the auxiliary electric fuel pump, enrich the mixture, and open the alternative air intake. Despite these efforts, the engine power could not be restored, forcing the pilot to execute an emergency landing on a dirt runway in Canabrava do Norte. During the landing roll, the aircraft's right landing gear struck a hole in the terrain, causing the aircraft to veer off the runway. The aircraft sustained severe damage to the propeller blades, right landing gear, right flap, and right aileron. The pilot and two passengers were uninjured.
The investigation
CENIPA investigators examined the engine components and fuel system following the accident. Laboratory tests of the fuel showed it was of satisfactory quality. Inspection of the propeller blades revealed they were symmetrically curved backward, indicating they struck the ground with low rotation and without developing traction.
Technical analysis of the fuel pumps revealed two distinct failures. The primary mechanical fuel pump showed evidence of a manufacturing defect in the diaphragm, where an incorrectly dimensioned hole had allowed air to enter the system and fuel to leak. Simultaneously, bench tests of the auxiliary electric fuel pump revealed a fuel leak at the brush support housing. Evidence suggested that an undocumented maintenance intervention had previously disassembled this pump, and the failure to replace or correctly install the sealing rings led to the leak.