What happened
On January 25, 2010, an EMB-110 aircraft, registration PT-TAF, operated by Piquiatuba Táxi-Aéreo Ltda., was performing a flight from Belém, PA, to Senador José Porfírio, PA. The aircraft was carrying two pilots and eight passengers.
During the descent, while crossing 2,500 feet, the co-pilot observed a significant increase in the interturbine temperature (TIT) in the left engine. In response, the commander reduced power to the affected engine. However, the aircraft was unable to maintain level flight, forcing the crew to execute an emergency landing in a pasture near Fazenda Rosinha. The impact resulted in two fatalities (the pilot and one passenger) and two serious injuries among the remaining occupants. The aircraft sustained severe damage.
The investigation
CENIPA's investigation focused on the engine's performance and the maintenance history of the aircraft. Investigators examined the maintenance records of the PT6A-27 engines, specifically looking at the transition of maintenance programs between different operators. The investigation scrutinized the application of Service Bulletin (SB) P&WC nº 1803R2, which allows for extended Time Between Overhaul (TBO) intervals under specific conditions.
Technical analysis revealed discrepancies in how maintenance intervals were calculated following the transfer of the engines to the operator. Investigators also identified the use of non-aeronautical components, such as a non-standard nipple found in the left propeller governor, and noted issues regarding the traceability of certain parts.