What happened
On November 28, 2008, an EMB-711T aircraft, registration PT-RHL, departed from Teruel Aerodrome in Campo Grande, Brazil, bound for Dourados. Approximately five minutes into the flight, while climbing to FL085, the aircraft experienced a propeller overspeed followed by a complete engine seizure. The pilot attempted to manage the RPM by reducing power and leaning the mixture to return to the departure airfield, but the engine failed shortly thereafter. The pilot was forced to perform an emergency landing in an open field approximately six kilometers from the Teruel Aerodrome. The pilot escaped the crash uninjured, but the aircraft sustained severe damage to the wings, fuselage, engine, and propeller.
The investigation
CENIPA investigators examined the wreckage and the aircraft's maintenance history. Post-accident analysis of the engine revealed a crack exceeding 20 inches in the engine block, extending to the valve stems. A significant amount of engine oil was found on the lower fuselage, and the oil dipstick was completely dry. Upon inspecting the aircraft in a hangar, investigators discovered that the oil drain valve was in the open position.
Further investigation into the recent 50-hour inspection revealed that the correct oil drain plug (PN STD-5 .551) had been replaced with an inappropriate drain (PN 61879-02). This unauthorized and unrecorded substitution was the critical error. When the nose gear was retracted, the landing gear strut physically struck the drain valve, forcing it into the open position and draining the oil from the crankcase. Additionally, the maintenance facility's Technical Maintenance Control department lacked essential manufacturer service bulletins (BI 700-79-002 and BS 700-011-0008) that specifically warned against using the incorrect drain part on this aircraft model.
Findings
- The inappropriate installation of an incorrect oil drain during a recent 50-hour inspection allowed the oil to escape.
- The physical movement of the nose gear retraction mechanism struck the drain valve, opening it.
- The maintenance company lacked the necessary technical publications to identify the risks associated with the incorrect part.
- There was a lack of adequate maintenance supervision to verify the compatibility of the newly installed component.