What happened
On May 28, 2017, a PA-34-2-20T, registration PT-WPD, was performing a private transport flight from Arruda Ramos Farm Aerodrome in Mato Grosso to Araçatuba in São Paulo. The flight, carrying a pilot and one passenger, proceeded for approximately two hours and 40 minutes before the aircraft struck two trees in a pasture area near the Seriema Farm in Coxim, Mato Grosso.
The impact with the first tree, which was approximately one meter high, caused the right engine and right wing to separate from the airframe. The aircraft then struck a second tree, which resulted in the separation of the outer section of the left wing. The fuselage and tail cone eventually came to rest upside down. A post-impact fire consumed much of the aircraft's structure and cabin. The pilot and the passenger both sustained fatal injuries.
The investigation
CENIPA investigators examined the wreckage and conducted bench tests on the engines. Although the fire destroyed much of the aircraft's documentation and flight instruments, investigators were able to determine that the aircraft was configured for landing, as evidenced by the state of the landing gear and flaps.
Technical analysis of the right engine revealed that the servo-injector was operating with a fuel flow outside of the manufacturer's limits, resulting in an over-rich mixture. This was evidenced by the presence of black soot inside the cylinders. Investigators also noted that while the left engine appeared operable, both engines showed evidence of having lost power prior to the final impact with the ground.
Findings
- The right engine's servo-injector was operating with an excessively rich fuel mixture, which may have caused an engine malfunction.
- The pilot may have attempted to correct the engine's irregular operation by abruptly adjusting the power or fuel levers, potentially leading to a significant loss of power or an engine cutout.
- There was a possibility that the pilot struggled to correctly identify and manage the abnormal engine condition, impacting the decision-making process during the emergency.
- The aircraft was configured for landing at the time of the crash, suggesting an attempted emergency landing due to a probable failure of the right engine.