What happened
On March 2, 1998, an EMB-110 operated by Rico Linhas Aéreas was performing a scheduled passenger flight from Maués to Manaus. While flying at 6,500 feet near the Manaus Terminal Area, the crew observed fuel pump cycling in the left engine, followed by a drop in torque. The pilot followed standard procedures to feather and shut down the left engine.
Approximately eight minutes later, the right engine also experienced irregular operation, including torque loss and eventual shutdown. Faced with total power loss, the crew executed a forced landing in Lago do Aleixo. The aircraft impacted the water with the landing gear retracted and flaps at 100% extension. All six occupants (two crew and four passengers) evacuated the aircraft via the left wing and were rescued by local boats; no fatalities were reported. While the aircraft remained afloat initially, it eventually submerged. The airframe sustained heavy damage during recovery and was deemed a total loss.
The investigation
CENIPA's investigation established that the engine failures were the direct result of fuel exhaustion. Research conducted with EMBRAER confirmed that the engines stopped due to a lack of fuel supply. The investigation revealed that the aircraft had departed without being refueled, despite appearing ready for flight.
On the morning of the accident, the ground support team experienced several disruptions, including a mechanical failure on another aircraft and the need to retrieve missing navigation charts and checklists. These distractions led to a breakdown in the refueling sequence. Furthermore, a company priority policy directed the refueling truck to service an EMB-120 aircraft before the PT-WDC, leaving the EMB-110 without fuel. The investigation also noted that the crew was restricted from personally verifying refueling levels due to an existing friction between the operations and maintenance departments.
Findings
- Fuel Exhaustion: The primary cause of the dual engine failure was the lack of fuel in the tanks.
- Distraction and Attention Fluctuation: Ground personnel were distracted by the search for missing documentation and a simultaneous mechanical issue on another aircraft, which led to the failure to complete the refueling of the PT-WDC.
- Organizational Culture: A lack of oversight and a breakdown in communication between maintenance and operations prevented the verification of fuel levels. The crew mistakenly believed the aircraft had been serviced because they saw the refueling truck positioned in front of the aircraft.
- Deficient Supervision: The company lacked robust mechanisms to ensure refueling was completed and documented, allowing the aircraft to depart without sufficient fuel.