2015 Senegal mid-air collision
|Date||5 September 2015|
|Summary||Mid-air collision, probable instrument malfunction|
|Site||Approx 130 km (80 mi) east of Tambacounda, Senegal |
A B737-800 of Ceiba Intercontinental Airlines similar to the aircraft involved
|Operator||Ceiba Intercontinental Airlines|
|IATA flight No.||C271|
|ICAO flight No.||CEL071|
|Call sign||CEIBA LINE 071|
|Flight origin||Léopold Sédar Senghor International Airport, Dakar, Senegal|
|Stopover||Cotonou Cadjehoun Airport, Cotonou, Benin|
|Destination||Malabo International Airport, Malabo, Equatorial Guinea|
An HS-125-700 similar to the aircraft involved
|Type||Hawker Siddeley HS-125-700A|
|Flight origin||Ouagadougou Airport, Ouagadougou, Burkina Faso|
|Destination||Léopold Sédar Senghor International Airport, Dakar, Senegal|
On 5 September 2015, Ceiba Intercontinental Flight 71, a Boeing 737 passenger jet en route from Dakar, Senegal, to Malabo, Equatorial Guinea, collided mid-air with a Hawker Siddeley HS-125 air ambulance jet operated by Senegalair. The 737 was slightly damaged and managed to land safely at Malabo, but the HS-125, after remaining airborne for almost an hour with the crew unresponsive, eventually crashed into the ocean, killing all seven people on board.
The two aircraft collided at 18:13 approximately 130 km (80 mi) east of Tambacounda, Senegal, while cruising at an altitude of 35,000 feet (11,000 m) along the same airway in opposite directions, in an area with no radar coverage. The impact sheared off the top 1-metre section of the Boeing's right winglet and was registered on the on-board flight data recorder as a brief oscillation and an uncommanded yaw promptly corrected by the autopilot.
It is believed that air ambulance 6V-AIM was struck on the fuselage, resulting in the loss of cabin pressure and the incapacitation of the crew. The HS-125 continued flying for a further 55 minutes without the crew responding to any of the several attempts made to contact them. It flew past Dakar, its intended destination, before presumably running out of fuel and crashing into the Atlantic Ocean around 110 km (70 mi) west of Dakar. The wreckage was not recovered.
The crew of the Ceiba 737 in the meantime had assessed that their aircraft was operating normally, and decided to skip the scheduled stopover at Cotonou, Benin, and instead continue directly to Malabo (the airline's operating base), where it landed without further incident.
The Ceiba aircraft was a Boeing 737-8FB with Equatorial Guinean registration 3C-LLY, which had been in service since February 2014. The air ambulance was a Hawker Siddeley HS-125-700A, Senegalese registration 6V-AIM, that had been in service since 1979.
In August 2017, the Senegalese Bureau of Enquiry and Analysis for Civil Aviation Safety (BEA Sénégal) released a final report stating that the probable cause of the accident was the failure of the HS-125 crew to maintain the assigned flight level, which the crew had correctly acknowledged and read back to the air traffic control.
The report also noted that there had been previous incidents involving 6V-AIM in which a significant discrepancy was registered between the altitude indicated by the plane's altimeters and transponder, suggesting a possible fault in the aircraft's pitot-static system that may also have contributed to the accident. The report also lists as a possible contributing factor a failure by Senegalair's crew and maintenance staff to comply with established procedures, mentioning several previous detected instances.
Both aircraft were equipped with TCAS collision avoidance system, and the Ceiba 737's unit was subsequently analysed and found to be working correctly. Despite this, the Ceiba crew received no TCAS warnings prior to the collision, a circumstance that according to the report could have been the result of the HS-125's instrument failure and resulting discrepancy between the altitude information shown on the altimeter and the one fed to the transponder and TCAS systems.
- Gol Transportes Aéreos Flight 1907 – a similar mid-air collision occurred in Brazil in 2006
- List of civilian mid-air collisions
- BEA Sénégal 2017, Annex 1.
- BEA Sénégal 2017, section 1.11.3.
- "ASN Aircraft accident Hawker Siddeley HS-125-700A 6V-AIM Dakar, Senegal". aviation-safety.net. Retrieved 20 September 2018.
- Hradecky, Simon (21 August 2017). "Accident: Ceiba Intercontinental B738 over Senegal on Sep 5th 2015, midair collision with ambulance jet (updated)". The Aviation Herald. Retrieved 20 September 2018.
- Kaminski-Morrow, David (22 August 2017). "BAe 125 altimeter flaw suspected after 737 mid-air collision". FlightGlobal. Archived from the original on 14 August 2018. Retrieved 18 September 2018.
- "ASN Aircraft accident Boeing 737-8FB (WL) 3C-LLY Tambacounda". aviation-safety.net. Retrieved 20 September 2018.
- BEA Senegal, p. 13 (PDF p. 14).
- BEA Sénégal 2017, section 3.2.1.
- BEA Sénégal 2017, section 3.2.2.
- BEA Sénégal 2017, p. 108.
- BEA Sénégal (1 August 2017). Accident survenu le 05 septembre 2015 dans la FIR terrestre de Dakar entre le Boeing 737-800 immatriculé 3C-LLY exploité par Ceiba Intercontinental et l’aéronef médicalisé HS 125-700A immatriculé 6V-AIM exploité par Senegalair [Accident happened on 05 September 2015 within the Dakar terrestrial FIR involving the Boeing 737 registered 3C-LLY, operated by Ceiba Intercontinental, and the air ambulance HS 125-700A registered 6V-AIM, operated by Senegalair] (PDF) (Report) (in French). Dakar: Ministry of Tourism and Air Transport. Retrieved 20 September 2018.