Incident
On a morning flight from Buenos Aires to Río Cuarto, an airplane departed at 0515 local time. Less than two hours into the flight, the crew contacted Río Cuarto and was informed of poor weather at the destination. Despite conditions below minima, the pilot decided to start an instrument flight rules (IFR) descent. During the descent, the airplane struck the slope of a mountain and disintegrated on impact, killing all 18 occupants.
Investigation
The official investigation determined the probable cause of the accident. The primary factor was the pilot's decision to descend en route without justifiable reason below the minimum altitude prescribed for a night flight, and in weather conditions that made it his duty to follow IFR procedure. A contributing cause was probably an error between the control tower and the aircraft in the transmission or interpretation of barometric pressure values (QFE and QNH).
Aftermath
The accident highlights the risks of descending below minimum safe altitudes in adverse weather conditions, especially at night. The investigation did not specify further details regarding the aircraft type, registration, or operator.