What happened
On May 6, 2021, an experimental RV-10, registration PR-ZSF, departed from Santa Maria International Airport (SBAR) in Aracaju, Brazil, bound for Unaí, Minas Gerais. Shortly after taxiing for takeoff, the pilot reported a panel malfunction and returned to the parking apron. After resolving the initial issue, the pilot requested and received takeoff clearance for runway 12.
Approximately three minutes into the takeoff roll, the pilot notified the tower of his intention to return to the airport, reporting that he had "lost" the trim control. During the subsequent approach to runway 30, the aircraft impacted a mangrove area at a high angle of incidence and high speed. The aircraft was destroyed, and the pilot sustained fatal injuries.
The investigation
CENIPA investigators examined the wreckage and the elevator trim system components. While the servo actuator itself showed no functional failure during bench testing, it was found in a fully extended position, which corresponds to the trim being deflected upward. This deflection would have forced the elevator downward, inducing a steep dive.
Because the servo actuator was functional, the investigation focused on the electrical system, including switches, relays, and wiring. Investigators identified a Service Bulletin (SB001/17-Flyer) regarding similar RV-10 aircraft, which warned that accidental contact between control wires and the stick structure could trigger the electric trim relay, causing involuntary movement to maximum deflection. Although the subject aircraft was an amateur-built model from 2014, the investigation inferred that an unintended activation of the trim servo due to an electrical failure was the primary cause of the loss of control.
Findings
- The aircraft was an amateur-built experimental model operating under a valid experimental certificate.
- The pilot was fully qualified with valid medical and instrument ratings.
- The investigation identified that the trim servo was found in a position that would cause a nose-down pitch.
- An unintended activation of the electric trim via the electrical system led to the loss of flight control.
- Maintenance records for the engine, propeller, and airframe were not located.
Safety action
CENIPA issued recommendations to the National Civil Aviation Agency (ANAC) to:
- Alert operators of RV-10 and RV-10A experimental aircraft to inspect the condition of trim actuator wiring to prevent accidental contact with the control stick.
- Ensure operators of aircraft affected by Service Bulletin SB-001/17-Flyer are strictly adhering to the prescribed safety measures.