AVIATION/ AUSTRIAN 737 & ASIANA 747 IN NEAR COLLISION AT VIENNA

Austrian aviation officials have launched an investigation into a near collision between an AUSTRIAN AIRLINES Boeing 737 and an ASIANA Boeing 747 at Vienna, Austria, on Saturday, June 4. Austrian Flight 798 was on International Service from Sofia, Bulgaria, to Vienna, while Asiana Flight 795 was on International Service from Moscow, Russia, also to Vienna. Austirian Flight 798 was on approach to the runway 16 at Vienna, when it went around due to severe turbulence. The published go-around procedure would require the aircraft to climb out on runway heading, then turn towards SNU VOR south of Vienna, however there were severe thunderstorm cells in the go-around path. Due to the storms, the crew of Flight 798 turned immediately to the right onto a heading of 300 degrees. According to reports, the crew was slow to change frequency and it was about 1 minute before they contacted approach controller. The 737 turned past the assigned heading of 300 degrees onto about 340 degrees and climbed to 5000 feet, tracking about 1.4nm west of and parallel to the localizer beam opposite to landing traffic at about 250 knots ground speed. At the same time, Asiana Flight 795 was also on approach to the runway 16 and was already established on the localizer at 5000 feet MSL slowing down to about 170 knots ground speed. At 5:05:37pm,  the separation between the 2 aircraft was approximately 6.5 nautical miles horizontal and 0 feet vertical, at 5:06:31pm, the separation had been reduced to approximately 1.4nm horizontally and 500 feet vertically. The crew onboard Asiana Flight 795 reacted to a go-around instruction by Air Traffic Control and rapidly climbed, reaching 5500 feet with the Austrian 737 still at 5000 feet when the aircraft crossed abeam. of each other. The Asiana 747 subsequently climbed to 9000 feet and landed safely on runway 16 about 20 minutes after initiating the unexpected climb. The Austrian 737 landed safely on runway 16 about 14 minutes after the loss of separation. According to media reports, the tower and approach controllers on duty at the time of the incident have been relieved from their positions. Austrocontrol, which provides the air traffic control services said that the Austrian crew requested a specific heading and was cleared to track that heading. The crew however diverted from that heading without clearance and without informing ATC probably due to the severe thunderstorms. In a statement, Austrian Airlines said that the crew aborted the approach to the runway 16 due to weather. A heavy thunderstorm had arrived over the airfield blocking the standard go-around procedure, which forced the crew to conduct an immediate change of course. Austrian said it was because of the storm that the crew of Flight 798 was therefore unable to inform ATC about the new flight path immediately. Austrian did report that their crew did received a TCAS alert during the incident. Asiana has not commented. A full investigation has been launched. Reports say that investigators will also look at other aircraft in the area at the time of the incident and how they reacted to the weather.