What happened
On the night of June 24, 1998, an Embraer E-810 Sêneca, registration PT-VDI, departed from Porto Nacional, Brazil, bound for Brasília. The aircraft was performing an air medical transport mission, carrying two crew members and three passengers, including one patient.
Approximately 20 minutes into the flight, while leveled at 8,000 feet, the aircraft experienced a failure of the left engine. During the pilot's attempt to manage the emergency, the engine ceased functioning entirely. The crew attempted to return to Porto Nacional, but the aircraft could not maintain level flight. The aircraft entered a continuous descent, eventually striking trees and colliding with rocky, mountainous terrain approximately 30 km from the airport. The impact caused a post-crash fire that completely destroyed the aircraft. The accident resulted in four fatalities and one serious injury.
The investigation
CENIPA's investigation focused on the cause of the engine failure and the inability to maintain altitude. Laboratory analysis of a fractured crankshaft from the left engine revealed that the failure was caused by an overload, likely due to torsional stress. Evidence suggested that a dynamic balance weight had detached from the crankshaft, damaging the engine casing.
The investigation also identified significant maintenance and operational discrepancies. The aircraft's engines had exceeded their Time Between Overhaul (TBO) by approximately 98 hours. Furthermore, the operator failed to maintain copies of the aircraft's maintenance logs and had not recorded certain Airworthiness Directives (ADs) in the aircraft's control records. The investigation also noted that the aircraft had departed with an excess weight of approximately 109 kg.
Findings
- Inadequate Crew Coordination: The co-pilot was not qualified or rated for this aircraft type, which led to poor cockpit resource management and a lack of technical assistance to the commander during the emergency.
- Operational Oversight: The operator's management allowed a flight to proceed with an unqualified co-pilot and failed to ensure proper maintenance supervision.
- Maintenance Deficiencies: The engines were operated beyond their recommended overhaul limits, and essential airworthiness directives were not properly tracked.
- Weight and Balance: The aircraft was operating significantly above its maximum takeoff weight, which, combined with the drag from the failed engine, likely prevented the maintenance of level flight.