Flight Plan and Departure
The aircraft was scheduled to fly from Lanseria Airport (FALA) in South Africa to Bamako Airport (GABS) in Mali, with stopovers at Ondangwa Airport (FYOA) in Namibia, São Tomé International Airport (FPST) in São Tomé and Príncipe, and Accra Airport (DGAA) in Ghana. The estimated total flying time was approximately 15 hours, not including ground time at stopover airports.
Prior to the planned flight, the aircraft had been at Lanseria Airport for maintenance, including engine work and interior refurbishing. On Saturday, April 6, 2013, the aircraft underwent a 45-minute flight check after the completed maintenance, flown by the captain and another company pilot.
The aircraft departed FALA to FYOA, with a flight time of 3 hours and 35 minutes. Departure from FYOA was delayed due to trouble starting the right engine. The aircraft eventually took off at 1021 hours, contrary to the planned 0830 hours.
Final Leg and Communication
For the second leg from FYOA to FPST, the filed flight plan indicated a flight time of 5 hours and 20 minutes, with FYOA as the alternate airport. Leaving Namibian airspace, the pilot contacted Luanda Air Traffic Control (ATC) and São Tomé Tower as the destination. The pilot did not contact Brazzaville or Libreville for clearance within the Brazzaville Flight Information Region (FIR).
On that day, the west coast of Africa in the vicinity of the Gulf of Guinea experienced widespread moderate to severe thunderstorm activity with lightning and heavy rain. When initiating descent to São Tomé from flight level 200 to 4000 feet as instructed by São Tomé ATC, the pilot was advised that weather was gradually deteriorating at the airport vicinity.
At 1610 hours, the pilot had the last transmission with the control tower, reporting a position 9 nautical miles inbound to the São Tomé VOR at 4000 feet and encountering heavy rain. Contact was lost at 1613 hours. São Tomé ATC attempted to contact the aircraft via VHF frequencies 118.9, 127.5, 121.5, and HF 8903 without success. Messages were sent to FIRs of Brazzaville, Accra, and Libreville Control, and airlines flying within the area were contacted; all responses were negative.
Search and Rescue
A search and rescue operation started on April 7, 2013, conducted over the sea and on the island. No trace of the aircraft, its debris, the pilot, or any cargo was found. The search was terminated on April 20, 2013, at 1730 hours.