What happened
On December 6, 1993, a Cessna 208B, registered as PT-OGM, was performing a scheduled flight from Redenção to Tucumã, Pará, operated by Brasil Central Linhas Aéertas Regional S/A. The aircraft was carrying two crew members and two passengers.
During the descent for landing in Tucumã, the engine experienced a significant loss of power accompanied by high turbine inlet temperature (TIT), intense vibration, and audible popping noises. The crew attempted to implement the "Emergency Power Lever" procedure to restore power and reach the runway; however, the engine remained at idle. Due to the low altitude of the aircraft at the time of the failure, the crew executed a forced landing in an area near a hill. The landing site was characterized by irregular terrain and several obstacles, including trees, wooden stumps, and a wire fence. During the landing roll, the aircraft struck these obstacles, causing it to lose control and come to a stop 180 degrees from its original heading. The aircraft sustained severe damage to the main landing gear, left horizontal stabilizer, left wing tip, and left aileron. All four occupants emerged from the wreckage uninjured.
The investigation
CENIPA investigators examined the engine and fuel systems following the accident. Tests performed on the engine group and the FCV showed no operational abnormalities, and fuel analysis revealed no presence of water. The investigation noted that the symptoms—loss of torque, high TIT, and vibration—were highly consistent with a compressor stall.
While the crew members were highly experienced and held valid licenses, the investigation found that the company did not provide specific emergency procedure training for the C-208B model. Furthermore, the investigation looked into the maintenance history, noting that while periodic services were performed, there were indications that inadequate maintenance might have contributed to the engine failure.
Findings
- Deficient instruction: The crew lacked specific emergency situation training for this aircraft type, which hindered their preparation for a critical engine failure at low altitude.
- Deficient supervision: The operator failed to provide adequate technical and operational oversight by not ensuring crews were trained for emergency scenarios.
- Deficient maintenance: There were indications that inadequate maintenance services may have contributed to the occurrence of a compressor stall.
Safety action
- The company's training department was directed to implement an instruction and training program for C-208B crews within three months, focusing specifically on emergency procedures.
- The company was instructed to conduct semi-annual evaluations of C-208B crews, utilizing both written exams and flight simulators to assess emergency handling skills.
- The DAC (Department of Civil Aviation) was tasked with conducting a safety inspection of the TAM BRASÍLIA maintenance facility to identify factors that may have contributed to engine failures in the C-208B.