What happened
On October 18, 2019, a Cessna 208, registration PT-OGH, was performing a crewmember operational experience acquisition flight from Bauru to Jundiaí, São Paulo. While the aircraft was in the traffic pattern for landing at Comandante Rolim Adolfo Amaro Airport (SBJD), the crew experienced significant vibrations followed by a complete loss of engine power.
The pilot feathered the propeller and executed an emergency landing on runway 36. During the landing roll, two main landing gear tires burst due to the application of heavy braking. The aircraft overran the runway, coming to a stop approximately 10 meters beyond the threshold. There were no injuries to the two crewmembers or the single passenger on board, though the aircraft sustained minor damage to the engine and landing gear.
The investigation
CENIPA investigators examined the engine components and the flight sequence. Laboratory analysis of the exhaust duct revealed a fracture in the internal part of the duct at the terminal of the Py tubing. Metallographic examinations showed that the fracture region was characterized by corrosion pits and intergranular corrosion. The investigation also reviewed maintenance records, noting that the engine had accumulated 7,150.4 hours since its last overhaul, which is nearly double its original Time Between Overhaul (TBO) of 3,600 hours.
Findings
- The engine power loss was caused by a fracture in the exhaust duct.
- The fracture originated from corrosion pits within the exhaust duct and Py tubing.
- The landing was long, with touchdown occurring near the midpoint of the runway, leaving insufficient distance for a safe stop.
- Heavy braking during the emergency landing led to the bursting of the main landing gear tires.
- Potential contributing factors included inadequate maintenance supervision and the possibility that the extended engine service intervals under the MORE program may not have captured the ongoing degradation of the components.