What happened
On August 10, 2016, an EMBRAER EMB-810D, registration PT-VDH, was performing a private flight from Aruanã to Palmeiras de Goiás, Brazil, carrying a pilot and three passengers. Approximately 50 minutes into the flight, the pilot experienced a power loss in the left engine, noting a drop of over 280 RPM on the right magneto. Shortly thereafter, a similar power loss occurred in the right engine.
In response to the dual engine failure, the pilot attempted an emergency landing on an unregistered asphalt runway at Fazenda Floresta. During the landing sequence, the aircraft touched down approximately 380 meters from the threshold. Despite the application of maximum braking, the aircraft failed to stop within the available runway length, overran the pavement, entered a depression, and collided with a fence. All four occupants escaped the incident without injury, though the aircraft sustained light damage.
The investigation
CENIPA investigators examined the aircraft's maintenance history and performed bench tests on the Continental TSIO-360-KB engines. The investigation focused on the cause of the simultaneous power losses and the factors leading to the runway excursion.
Technical analysis of the right engine revealed a cracked fuel flow connection. Testing demonstrated that a leak at this connection caused a 250 RPM drop in engine speed. Further examination of the cracked fitting suggested that the damage was caused by over-torquing, likely an attempt to stop existing leaks caused by corrosion on the washer. Regarding the left engine, investigators found that the power anomaly was caused by faulty spark plugs; once the spark plug set was replaced, the engine functioned normally.
Regarding the landing, investigators calculated that based on the temperature, elevation, and weight, the aircraft required a total landing distance of 3,400 feet. The investigation determined that the late touchdown and the pilot's approach speed contributed to the inability to stop on the 900-meter runway.
Findings
- Improper maintenance of the right engine's fuel flow connection, involving an over-torqued fitting, led to a fuel leak and power loss.
- Faulty spark plugs caused the initial power loss in the left engine.
- The pilot's flight controls input and piloting judgment contributed to the runway excursion.
- The late touchdown on the runway reduced the available distance for deceleration.