On Feb 19th 2017 The Aviation Herald was able to obtain a copy of the preliminary report in French released by Senegal's BEA on Jan 8th 2016. The BEA reported that C2-71 had been cleared to climb to FL350 at 17:50:54Z, the aircraft was subsequently handed off to Dakar Center. Dakar Center instructed C2-71 to maintain FL350 and report passing GATIL waypoint. At 18:15:32Z C2-71 contacted Dakar Center again, Dakar Center in response handed C2-71 off to the Bamako Control, the crew however reported that they saw traffic very near them in opposite direction, they believed it was a near collision. A minute later the crew advised they believed the opposite traffic had hit their wing. In the meantime Dakar Center tried to raise 6V-AIM, however, did not receive any response. Dakar informed C2-71 that the traffic in opposite direction was 6V-AIM, cleared to maintain FL340, they were unable to contact the aircraft. At 18:19:23Z C2-71 was handed off to Bamako Control, the crew inquired with Bamako Control about the traffic in opposite direction 5 minutes earlier. Bamako advised that the traffic, a Hawker Siddeley HS-25 was supposed to maintain FL340. Bamako tried to call the Hawker several times but did not receive a reply. At 18:24Z Bamako told C2-71 that the Hawker was in the Dakar Control Zone but could not be contacted. C2-71 advised they would file a inflight collision report.
The HS-125 had departed runway 22 of Ouagadougou Airport and at 17:01Z was cleared to climb to FL340. The aircraft was subsequently handed off to Bamako Control. On Bamako the crew estimated waypoint GATIL at 18:10Z and Dakar at 18:54Z. At 17:13Z the crew requested to climb to FL380 due to clouds ahead and was cleared to climb to FL380 at 17:13z. At 17:19z the crew reported turbulence at FL380 and requested to descend or climb advising they had a sick passenger on board. At 17:22Z the crew was cleared to climb to FL400, however, reported at 17:30Z that there was turbulence too and requested to descend to FL340 again. At 17:31z the HS-125 was cleared to descend to FL340 and at 17:55z reported passing waypoint ENINO at FL340. Bamako Control instructed the HS-125 to contact Dakar Control upon passing waypoint GATIL at FL340. At 18:00z the Hawker contacted Dakar Center requesting a deviation of 10nm to the left of the airway to avoid bad weather. Dakar instructed the aircraft to maintain FL340 and set transponder to 5040. ATC requested the HS-125 to confirm they were maintaining FL340, the crew confirmed, then the crew requested ATC to confirm their transponder code 5040, ATC repeated transponder code 5040. This proved to to be the last radio contact with the aircraft, the crew did not respond to any further radio calls anymore. The aircraft appeared on Dakar's radar screen at FL350 at 18:22Z showing the transponder code 5004 (instead of 5040). At 19:01Z the aircraft overflew Dakar VOR at FL350 and continued on a track of 293 degrees. At 19:07Z the radar shows the aircraft began to descend and turned right. A short time later the aircraft descended through FL126 and disappeared from radar screen about 59nm from Dakar VOR at approximate position N14.9789 W18.4703.
The HS-125 was flown by a captain (59, CPL, 7,685 hours total, 5,500 hours in command) and a first officer (35, CPL, 3,339 hours total). The aircraft had accumulated 13,279 flight hours in 11,877 flight cycles.
The Boeing 737-800 was flown by a captain (45, ATPL), a second captain (45, ATPL) and a first officer (33, 585 hours total). The aircraft had accumulated 1,568 flight hours in 1,761 flight cycles.
The HS-125 has not been found to date, the BEA reported. Part of the right winglet was missing from the Boeing, the part has not been found.
The BEA reported that according to weather reported there were thunderstorms and low clouds present in the vicinity of the FIR boundary between Senegal (Dakar) and Mali (Bamako). However, there was no problem of visibility at the cruise levels.
The flight data and cockpit voice recorders of the Boeing 737 were read out normally by the BEA France, representatives of BEA Senegal, representatives of the CAA Equatorial Guinea and the operator were present. The flight data recorder contained 90 hours of flight storing 1200 parameters. The cockpit recorder contained 124 minutes of flight, the recording did not include the actual event. The FDR revealed the Boeing 737 was enroute at FL350 with autopilot engaged. TCAS was operative and in good condition (editorial note: the report does not mention a TCAS traffic or resolution advisory nor does the report mention that no advisory was generated).
Accident: Ceiba Intercontinental B738 over Senegal on Sep 5th 2015, midair collision with ambulance jet