Departure and Flight
The aircraft departed Ouagadougou Airport at the end of the afternoon on an ambulance flight to Dakar-Léopold Sédar Senghor Airport. On board were one patient, one doctor, two nurses, and three crew members. After contacting Dakar Control, the crew was cleared to flight level 340 (FL340), which was confirmed by the crew at 1801 LT. However, the airplane continued climbing and reached FL350.
Collision and Aftermath
At 1812 LT, the aircraft collided with a Boeing 737-8FB registered as 3C-LLY, operated by Ceiba Intercontinental on flight CEL071 from Dakar to Cotonou and Malabo. The Boeing carried 104 passengers and 8 crew members. Immediately after the collision, the BAe 125 entered an uncontrolled descent and crashed into the Atlantic Ocean approximately 111 km off Dakar. The pilot of the Boeing 737 informed air traffic control about a possible collision and continued to Malabo without further problems. The top of the right winglet of the Boeing was missing. Search and rescue operations were suspended after one week, and no trace of the BAe 125 nor its seven occupants was ever found.
Probable Cause
The official investigation stated that the collision was the consequence of an error by the crew of the BAe 125, who failed to follow their assigned altitude of FL340 and continued to FL350, which was the assigned altitude for the Boeing 737. The captain of the Boeing 737 confirmed that he saw the aircraft descending toward him. Only the flight recorders could have helped determine how such a situation occurred, but they disappeared with the aircraft. There was a difference of 1,000 feet in the indications of both the captain's and copilot's altimeters.