What happened
On May 30, 2018, a Raytheon C-90A, registration PR-VIM, was performing a private flight from Primavera do Leste to the Derso Portilho Vieira Aerodrome in São Félix do Araguaia, Mato Grosso. The aircraft was carrying a pilot and two passengers.
During the landing phase, the aircraft's main and nose landing gears unexpectedly retracted while the plane was still on the runway. This caused the aircraft to veer off the right side of the unpaved runway into a nearby field. The impact resulted in substantial damage to the aircraft, though all three occupants escaped without injury.
The investigation
CENIPA investigators analyzed the aircraft's Cockpit Voice Recorder (CVR) and conducted mechanical tests on the landing gear system. The investigation confirmed that the pilot was fully qualified, with valid medical and instrument ratings, and that the aircraft was airworthy and within weight and balance limits. Meteorological conditions at the time were favorable for flight.
Analysis of the CVR revealed that a landing gear warning alarm began sounding 48 seconds before touchdown and continued for 20 seconds. The alarm briefly ceased, possibly due to a power adjustment by the pilot, but then resumed 2/22 seconds before touchdown and continued until the aircraft came to a complete stop. Subsequent mechanical testing by a certified maintenance organization found the landing gear deployment and retraction system to be functioning perfectly, with no mechanical failures detected during the investigation.