Two planes came alarmingly close to each other when flight crew misheard an air traffic control instruction during a landing in windy weather.
However, the pilots misheard the instruction and instead turned left.
This put them in the flight path of another plane, a Bombardier Dash 8 aircraft, which was descending to land around 11km away.
The crew of the Superjumbo was then instructed to turn right and climb immediately; while the crew of the Dash 8 aircraft were instructed to make a right turn to maintain an acceptable distance between the planes.
However, this then resulted in the Dash 8 plane flying close to another passenger plane, a Boeing 737, which was also getting ready to land at Sydney airport.
This caused a “loss of separation”, with the distance between the Dash 8 plane and the 737 aircraft reduced to 4.8km laterally and 397m vertically.
Nats, which oversees air traffic control around the world, says: “The minimum standard separation between two aircraft is either 3 or 5 miles apart laterally (depending on the type of airspace) or 1,000ft vertically.”
“The ATSB found that the A380 flight crew were likely experiencing a high workload managing a high-energy aircraft state as a result of conducting the windshear recovery and missed approach,” said ATSB acting director transport safety Kerri Hughes.
“This, in combination with an expectation that they would be turning left, contributed to the flight crew mishearing the ATC instruction to turn right.”
Ms Hughes said the incident had emphasised the importance of pilots reading back air traffic control instructions to make sure everything is clear.
“The flight crew omitted the direction of the turn from their readback, which was not corrected by ATC. This was a missed opportunity to correct the misheard instruction,” she said.