What happened
On September 29, 2021, a Beechcraft Baron 58, registration PT-LMU, was conducting a ferry flight from Porto Velho (SBPV) to Cuiabá (SBCY) for scheduled maintenance. The aircraft was operated by the Military Fire-Fighting Department of Rondônia (CBMRO). During the cruise phase of the flight, the crew observed oscillations in the fuel flow of the right-hand engine, which subsequently led to a total loss of power from that engine.
Unable to maintain altitude, the crew performed a forced landing in an agricultural zone at Fazenda Lagoa Bonita, near Vilhena, Rondônia. The aircraft sustained substantial damage to the left-hand main landing gear, left-hand engine, propeller assembly, wing, flaps, and aileron. Both crewmembers escaped the wreckage without injury.
The investigation
CENIPA's investigation focused on the mechanical failure and the organizational environment of the operator. Technical examinations of the engine and its accessories revealed that the mechanical fuel pump was delivering a flow rate below the required specifications. This was traced to the improper positioning of the pressure-adjustment screw on the pump.
Investigators also identified several operational and organizational discrepancies. While the aircraft had a valid airworthiness certificate, there were reports of a long-standing fuel leak in the right-hand wing and an unreliable fuel gauge, neither of which had been recorded in the aircraft logbook. Furthermore, the investigation found that the pilot on the right-hand seat lacked the necessary multi-engine land (MLTE) qualification for the aircraft type.
Findings
- The mechanical fuel pump failure was caused by an incorrectly positioned pressure-adjustment screw.
- The crew failed to correctly apply the emergency procedures prescribed in the Pilot's Operating Handbook (POH) following the engine failure.
- The pilot's attempt to maintain flight through improvised actions and improper piloting techniques led to a loss of controlled altitude.
- A culture of informality existed within the organization, characterized by a lack of formal approval for training programs and manuals.
- There was a lack of oversight regarding maintenance records, as known discrepancies like fuel leaks were not documented in the logbook.
- The pilot in command was experiencing high workload due to accumulating multiple administrative and operational functions.