What happened
On April 6, 2013, an aircraft was engaged in a multi-leg journey originating from Lanseria Airport in South Africa, with scheduled stops in Namibia, São Tomé and Príncipe, and Ghana. The aircraft had recently undergone maintenance, including engine work and interior refurbishment, and had completed a 45-minute flight check earlier that day. After a delay in Namibia caused by difficulties starting the right engine, the aircraft departed Ondangwa for São Tomé.
During the flight leg toward São Tomé, the pilot transitioned through Namibian airspace and contacted Luanda ATC and São Tomé Tower, but failed to establish contact with controllers in Brazzaville or Libreville while traversing the Brazzaville FIR. At the time, the region near the Gulf of Guinea was experiencing widespread moderate to severe thunderstorms, characterized by heavy rain and lightning.
As the aircraft began descending from FL 200 to 4000 feet, São Tomé ATC warned the pilot of deteriorating weather conditions near the airport. The final communication from the aircraft occurred at 1610hrs, with the pilot reporting a position 9 nm inbound to the São Tomé VOR at 4000 feet and noting the presence of heavy rain. Contact was lost at 1613hrs. Despite repeated attempts by ATC to reach the aircraft via multiple VHF and HF frequencies, no response was received.
Findings
A search and rescue operation commenced on April 7, 2013, covering both the sea and the island. The mission yielded no trace of the aircraft, debris, or the crew. The search was officially ended on April 20, 2013. The investigation noted that the pilot encountered heavy rain and severe thunderstorm activity during the final stages of the flight.