2015-09-05 Ceiba 737-800 mid-air collision with HS-125 Jet over Senegal
The aircraft was involved in a mid-air collision with a Corporate Jet over Senegal. While the 737 landed safely, the latter aircraft later crashed in sea killing all seven on board.
On 2017-08-21, the Senegal Bureau d’enquête et d’Analyse (BEA) published its FINAL REPORT.
The BEA concluded the probable cause of this accident was:
The collision is due to the Hawker HS-125 (6V-AIM)’s non-compliance with its flight level. The Boeing 737-800 (3C-LLY) was assigned flight level 350.
At 18H01’11¨, 6V-AIM had confirmed ATC to maintain the 340. The 3C-LLY CBD claimed to have seen it come down on them. Only flight recorders could have helped to determine how such a situation may have occurred; Unfortunately, they disappeared with the plane.
The lack of altimetry may have contributed to the collision in flight.
CONTRIBUTIVE FACTORS – Altimetry problems
These problems may have contributed to the collision. The indications of the two
altimeters were different; Altimeter indications for the communication pilot and the altitude data transmitted by the transponder were different from about one thousand (1000) feet.
On 2015-07-23 , the aircraft was detected at level 310 instead of the 320 assigned by ATC controller and indicated by the altimeter.
On 2015-08-31, 6V-AIM was coordinated by Roberts: Point SESEL at 20H55 and FL 360. Once in radar contact, it was detected at FL 350 without any revision or authorization. Interestingly, he started to go up.
On 2015-09-05, on the outward flight (DKR – OUA), the aircraft had triggered two alarms CLAM:
– Rated flight level 330 and level acquired by autopilot 311
– Rated flight level 330 and level acquired by autopilot 333:
The full report (in pdf format) is available HERE
On January 2016, the Senegal Bureau d’enquête et d’Analyse (BEA) reported an update to the current investigation process.
The Hawker HS-125 erroneously was flying at a level 1000 ft above their original clearance. ATC cleared the flight to 34.000 ft. (FL 340) but instead the pilots levelled of at 35.000 ft (FL 350) putting themselves on the same altitude as the opposite flying 737.
Air Traffic Control did not remind the pilots to correct their level nor did the pilots do any altitude changes before the collision took place.
Ceiba flight CEL 71, a Boeing 737-800, was flying enroute at 35.000 ft, heading southeast on airway UA601, a few minutes east of Tambacounda VOR when it encountered opposite traffic at the same level.
The other aircraft was a Hawker HS-125 (registration 6V-AIM) opertated by Senegalair. This aircraft was on a medical flight from Ouagadougou to Dakar with four passengers (among them a patient) and three crewmembers.
It is understood that no reports about any conflict were transmitted to Bamako air traffic control. The controller later raised alarm when the HS-125 failed to answer to repeated calls.
Both aircraft flew away from each other. The pilots of the 737-800 altered their destination to Malabo, Equatorial Guinea, their home base giving technical and security reasons for skipping their scheduled intermediate destination Cotonou.
But the smaller Hawker Jet never landed at Dakar. It continued to fly at cruiselevel, overflew the coastline until it ran out of fuel and presumably crashed into the ocean about 60 miles west of Dakar.
A search operation is underway at sea and in the air but no trace was found from this flight yet.
The next days, Senegal´s Civil Aviation Authority ANACIM published a press statement where the possibility of a mid-air collision was mentioned.
ANACIM press report (pdf): http://anacim.sn/IMG/pdf/-181.pdf
On Sep 8th Senegal officials (from foreign ministry) confirmed that a mid.air collision actually must have taken place because wing damage was found on the 737 that was consistent with a collision in mid-air. The upper third of the right winglet was sheared off (see photo below), causing „unusual noises“ heared by a number of passengers.
According to unconfirmed reports, there was a lack of en-route radar coverage preventing controllers to detect any aerial conflicts or STCA/TCAS alerts in time.
Apart from Senegal, french authority BEA was consulted to join the investigation.
As of Sep 17th , the 737 still remained on the ground Malabo awaiting repairs.
3C-LLY B738 after the incident
Date: 2015-09-05 Time: 18:13
Location: eastern Senegal airspace
Flight phase: ENR – Cruise, Descent, Holding
Damage to a/c: none
Flight no.: CEL 71
From: GOOY/DKR: Dakar Yoff To: FGSL/SSG: Malabo
Operator: Ceiba Intercontinental
Type: Boeing 737-800
Age a/c: 1,6 years
Constr. No.: 41157
© B.Leighton | flickr
Accident aircraft 6V-AIM
Occupants & Casualties
JACDEC 25-year Statistics :
- 1sth (and worst) safety occurence for the operator
- 311th safety occurence of type (Boeing 737-800)
- 22nd mid-air conflict occurence in Africa
- 1st safety occurence for aircraft in question
Order a Safety Report
Image & Information Sources
Copyright - Terms of Usage
All written and shown content on JACDEC.de is provided in the most accurate way. All information may be subject to changes because JACDEC.de cannot always ensure a full support of information updates to each news story.
No publication (or part of) provided by at JACDEC.de may be reproduced or transmitted in any form or by any means or by any information retrieval system without written permission from JACDEC. The below information includes unofficial information and should be treated as this. Editors cannot be held responsible for any errors or omissions caused by any information source mentioned herein. The nature of the following information should be regarded as preliminary.
Furthermore, the author cannot be held accountable for correctness, completeness or quality of the information provided herein. Liability claims regarding damage caused by the use of any information provided, including any kind of information which is incomplete or incorrect,will therefore be rejected.
For further terms and conditions, check our legal disclaimer section:
AP = Airport / AL = Airlines / Avn = Aviation / AW = Airways / C/N: Construction Number / DSP = Domestic Scheduled Passenger / DNP = Domestic Non-Scheduled Passenger / DSC = Domestic Scheduled Cargo / DNC= Domestic Non-Scheduled Cargo / GND = On the ground / parked, stored / FMN= Flying Mission, Air Work / FRY = Ferry-, Positioning Flight / IMC = Intrument Meteorological (flying) Conditions / ISP = International Scheduled Passenger / ISC=International Scheduled Cargo / INP = International Non-Scheduled Passenger / INC =International Non-Scheduled Cargo/ OPS = Flight Operation(s) / NRV = Non-revenue, Private Flight / TRN =Training Flight / TST = Test & Certification Flight / VMC = Visual Meteorological (flying) Conditions