Incident
On a domestic flight from Manaus to Tefé, Brazil, an EMB-110 Bandeirante was operated with 25 passengers on board, despite being certificated for a maximum of 19. For financial reasons, the crew decided to take more fuel than necessary, resulting in an excess takeoff weight of 852 kg.
Flight and Engine Failure
Approximately 20 minutes after departure, the oil pressure of the No. 2 engine dropped. The crew reduced engine power to 72% and continued toward Tefé. When the flight was 185 km from Manaus at flight level 85, the oil pressure dropped further to 40 psi and the turbine gas temperature (TGT) increased. The copilot shut down the engine, and the captain turned the airplane around to return to Manaus.
At 13:15, the crew contacted Manaus Area Control Center (ACC), reporting that they were returning on one engine. The overloaded airplane, flying on a single engine, began to lose altitude. During the descent, the speed was maintained around 105 knots, which occasionally activated the stick shaker. To reduce weight, the left overwing exit was opened and passenger luggage was jettisoned.
Emergency Landing
The airplane did not reach Manaus. Instead, an emergency landing was made on the Manacapuru River. The Bandeirante touched down hard on the water, causing an opening in the fuselage. The aircraft sank quickly.
Probable Cause
The official investigation identified the following factors: It was not possible to examine the debris to determine its contribution to the left engine failure. A possible failure to carry out a type B2 inspection and/or a type A1 inspection by an unqualified person may have contributed to the low oil pressure emergency. The owner of the air taxi company lacked adequate supervision in planning operations, allowing the aircraft to fly with an expired B2 inspection, excessive fuel, an unreasonable number of passengers, and pilots' salary conditioned on the flight. The crew made errors: improper use of cabin resources, non-compliance with operational rules, inadequate flight preparation (no cargo/passenger manifest review, no briefing, accepting an aircraft without inspection), and inadequate evaluation (proceeding after the first lubrication system failure instead of returning). The airline's support staff provided incorrect weight and balance information, and the mechanic performing the A1 inspection was unqualified. There was intentional non-compliance by the crew with manufacturer's operational rules. The commander did not foresee what was predictable, intentionally increasing the risk margin.