What happened
On April 10, 2018, a Beechcraft B-58, registration N6926Z, departed from Horco Molle airport in Tucumán, Argentina, bound for a private airfield in Gobernador Garmendia. Shortly after takeoff, the pilot contacted the Tucumán tower to file a visual flight plan. Because the airport was experiencing instrument meteorological conditions (IMC), the tower requested confirmation that the aircraft was operating under visual flight rules (VMC). After the pilot confirmed visual conditions, the tower cleared the flight to proceed without entering the Tucumán control zone.
At approximately 11:40 UTC, air traffic controllers lost contact with the aircraft. A search was initiated, and the wreckage was later located by a participating aircraft in a mountainous, forested area near El Naranjo. The aircraft had struck the western slope of a hill. The impact and subsequent fire completely destroyed the airframe, engines, and propellers. The pilot and three passengers, all of whom were 4 fatalities, perished in the accident.
The investigation
The investigation examined the meteorological conditions, the aircraft's technical state, and the operational procedures in place at the time. Investigators analyzed satellite imagery, which revealed that while the upper atmosphere was clear, low-level stratiform clouds and potential fog banks were present in the valleys of Tucumán. This was caused by a northward airflow bringing warm, moist air into the region during a period of maximum radiative cooling.
Technical analysis of the aircraft's equipment included an examination of the Emergency Locator Transmitter (ELT) and the GPS unit. While the ELT was found to be functional, the GPS unit was recovered with severe damage, including a destroyed screen, preventing further operational verification.
Findings
- The accident occurred during the cruise phase of flight in reduced visibility caused by low clouds and fog.
- The aircraft struck terrain while operating in a mountainous region.
- Meteorological conditions in the valleys included low-level moisture and clouds that significantly degraded visibility.
- The impact resulted in a post-crash fire that consumed the entire aircraft.