The Citation III crashed and disintegrated in a field en route between Valencia (VLN) and Puerto Ordaz (PZO) in Venezuela. The copilot gave his place on board to a passenger without any qualification to operate the aircraft, moments after takeoff. During the en-route flight phase, the secondary pitch trim system was activated, which would have resulted in an abnormal operation of the system, followed by violent loss of altitude and over speed condition. Possible Causes: Absence of Crew Coordination and disregard of the Co-pilot’s command post responsibilities. * The flight was performed, at least during the last 32 minutes, by the pilot in command with the aircraft passenger in the co-pilot’s seat. In this condition, it does not comply with RAV 60.2(a) and 60.10 (b), (e) and (d). In these circumstances, it was not possible to effectively perform emergency procedures for this condition, since the passenger was not capable of performing them. – Conscious modification of flight conditions. – The aircraft was in cruise, straight and level flight. The condition was altered by the actuation of the Secondary Trim Switch, which was not required for this flight condition, since this is an Emergency Trim System, in case the Primary System, presents a failure. – Abnormal operation of the Horizontal Stabilizer Pitch Trim System. – When the Horizontal Stabilizer Pitch Trim Secondary System double switch was actuated, it triggered an abnormal operation of the aircraft’s horizontal stabilizer trim system with runaway characteristics (Trim Runaway) and almost immediately caused an over-speed condition. This failure, which could have been of an electrical or mechanical nature, could not be solved according to the emergency procedures that could have been executed, as described in the AFM section 111, which inhibited the recovery of the aircraft and caused the impact against the ground with high speed and thrust.