What happened
On October 22, 2014, a Beechcraft 58, registration PT-WFO, was performing a verification flight following maintenance services at Campo Grande Airport (SBCG), Mato Grosso do Sul. The flight, operated by the State Secretariat of Justice and Public Security of MS, included a pilot and two passengers.
Shortly after takeoff, the aircraft experienced an intermittent electrical system failure, evidenced by fluctuating instrument light intensity. Due to the electrical instability, the pilot decided to return to the airport to perform a landing. While the crew believed the landing gear was down and locked—partially verifying this via a mirror on the engine cowling—the gear inadvertently retracted during the landing roll. The aircraft subsequently decelerated while resting on its fuselage, resulting in substantial damage to the airframe. All three occupants escaped the incident without injury.
The investigation
CENIPA's investigation focused on the electrical system and the aircraft's maintenance history. Investigators found that the aircraft was undergoing its first flights after recovering from a previous accident in 2012. While the aircraft held a valid Certificate of Airworthiness, several discrepancies were identified in its records. Specifically, the logbooks for the airframe, engine, and propeller were not up to date, with the last recorded flight hours dating back to October 2012.
Technical inspections revealed poor condition of the electrical wiring, including loose wires at various points, and an alternator lacking an identification plate. There were also concerns regarding the potential installation of unauthorized equipment, which may have interfered with the electrical system's stability. During testing, investigators were able to replicate the electrical fluctuations described by the crew.
Findings
- The primary contributing factor was the poor state of aircraft maintenance.
- The electrical system was in a degraded condition, characterized by improper wiring and unidentifiable components.
- Maintenance records for the airframe and components were outdated.
- The pilot was properly licensed and experienced for the flight profile.