Virgin Australia 737 pushed into sharp bank by wake from Emirates A380
In a second report in today’s Aviation Herald its author Simon Hradecky has penetrated the obsessional reluctance of the ATSB to tell all about an incident om which a Virgin Australia 737 which had just departed from Denpasar in Bali for Brisbane last September was ‘pushed aside’ into a steep bank by the wake turbulence from an Emirates A380 flying above it in the opposite direction.
At the time of the incident the ATSB wouldn’t identify the A380, or reveal anything else about the incident. However it did give it summary treatment in a ‘short’ aviation incident report compendium released yesterday.
The ATSB reported that the crew of VH-YIO had requested FL370 after departure from Denpasar, however, due to traffic at FL360 had been cleared to climb to FL350. Flight conditions at FL350 were smooth, the crew reported calm winds. The fasten seat belt signs were extinguished. About a minute later the crew observed traffic in opposite direction, according to the TCAS display the traffic was 1000 feet above and slightly to the left of their track, Air Services Austrialia radar data showed the A380 about 0.9nm left and 1400 feet above the Boeing 737.
A minute after the aircraft had passed each other the Boeing 737 encountered wake turbulence throwing the aircraft slightly to the right and then to about 45 degrees of bank to the left, a bank angle aural warning was issued, the autopilot reverted to steering wheel mode. The crew applied full right aileron, the aircraft however continued to roll left initially though at reduced roll rate before wings started to level, the duration of the encounter was about 10 seconds. Air Services Australia Radar data suggest that at that time the aircraft were separated 1400 feet vertically and 2.1nm horizontally, the flight data recorder revealed a maximum left bank angle of 40.4 degrees, the aircraft lost 40 feet of altitude during the turbulence encounter.
The ATSB quoted the Boeing crew stating, that they did not hear the term Super, used to identify the wake turbulence category, on any transmission they heard. Had they known an A380 was about to overfly them, they would have requested an offset off the airway center line. In a similiar situation, the crew of another flight had heard the term “Super” and had requested and was cleared for a 5nm offset from the airway, permitting the aircraft to pass the A380 without any encounter.