Military

Loss of control during initial climb after one of the engine failed for unknown reasons.

Emergency landing after being hit by ground fire.

The airport of Naryan-Mar is controlled by both civil and military services. The helicopter has been cleared to land by civil ATC and less than two minutes later, the aircraft was cleared by military ATC to land on the same runway. A lack of coordination between both ATC services was identified as the separation between both landings was insufficient. Nevertheless, it was also reported that the crew of the Antonov failed to follow ATC message after the controller in the tower instructed the crew to initiate a go-around procedure. The crew misinterpreted this order thinking ATC was referring to the lack of visibility and not to the presence of another aircraft on the runway.

The exact cause of the engine failure could not be determined with certainty. It is known that engines of this series had problems with gas-dynamic stability, especially at high angle of attack.

Controlled flight into terrain. No technical anomalies were found on the aircraft.

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).

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 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).