Narrative:At approximately 1510 hours UTC, 65 nautical miles west of the Namibian, coast, a US Air Force C-141B Starlifter collided with a German Air Force (Luftwaffe) Tupolev 154M in mid-air. The C-141B, serial number 65-9405 was using the call sign REACH 4201 and was operated by the 305th Air Mobility Wing; the Tupolev used the call sign GAF 074. At 1411 UTC, REACH 4201 had departed from Windhoek, Namibia. The aircraft was at its filed for and assigned cruise level of 35,000 feet (FL350). The aircraft was on its filed for and assigned flight plan routing. Earlier at 1035 UTC, GAF 074 departed Diori Hamani International, Niamey, Niger, after refueling, continuing to its next refueling stop at Windhoek. At the time of the accident, the aircraft was not at its filed for cruise level of FL390 but was still at its initially assigned cruise level FL350. The aircraft was on its filed for and assigned flight plan routing.
|Date:||Saturday 13 September 1997|
|C/n / msn:|| 89A-813|
|First flight:|| 1989|
|Engines:|| 3 Soloviev D-30KU-154-II|
|Crew:||Fatalities: 10 / Occupants: 10|
|Passengers:||Fatalities: 14 / Occupants: 14|
|Total:||Fatalities: 24 / Occupants: 24 |
|Collision casualties:||Fatalities: 9|
|Airplane damage:|| Written off|
|Airplane fate:|| Written off (damaged beyond repair)|
|Location:||120 km (75 mls) W off Namibia (Atlantic Ocean)
|Phase:|| En route (ENR)|
|Departure airport:||Niamey Airport (NIM/DRRN), Niger|
|Destination airport:||Windhoek(unknown airport), Namibia|
Windhoek ATC was in sole and continuous radio contact with REACH 4201 on VHF 124.7. The agency did not know GAF 074's movement. Luanda ATC , at one time, was in radio contact with GAF 074 on HF 8903, but they were not in radio contact with REACH 4201. Luanda ATC did receive flight plans for both aircraft but a departure message for only REACH 4201.
PROBABLE CAUSE: "The primary cause of this accident, in my opinion, was GAF 074 flying a cruise level (FL350) which was not the level they had filed for (FL390). Neither FL350 nor FL390 were the correct cruise levels for that aircraft's magnetic heading according to International Civil Aviation Organization regulations. The appropriate cruise level would have been FL290, FL330, FL370, FL410, etc.
A substantially contributing factor was ATC agency Luanda's poor management of air traffic through its airspace. While ATC communications could be improved, ATC agency û Luanda did have all the pertinent information it needed to provide critical advisories to both aircraft. If ATC agency Luanda was unable to contact GAF 074, it should have used other communication means (HF radio, telefax or telephone) to contact REACH 4201 through ATC agency Windhoek, as outlined in governing documents.
Another substantially contributing factor was the complicated and sporadic operation of the Aeronautical Fixed Telecommunications Network (AFTN).
Routing of messages to affected air traffic control agencies is not direct and is convoluted, creating unnecessary delays and unfortunate misroutings.
Specifically, ATC agency Windhoek did not receive a flight plan or a departure message on GAF 074, which could have been used by the controllers to identify the conflict so they could have advised REACH 4201.
In my opinion, the absence of TCAS was not a cause or substantially contributing factor, but the presence of a fully operational TCAS could have prevented the accident." (William H.C. Schell, jr., Colonel, USAF President, Accident Investigation Board)
» Air Mobility CommandNews Release 31.03.1998
» Aviation Week & Space Technology 22.09.1997 (31-32)
» Scramble 221