When the parallel runways are being used in a southerly direction (“south flow”), aircraft that arrive into Sydney from the south, east and west need to travel northwards to join the final approach path from the north. As they travel northwards some will pass over the eastern suburbs (labelled A3 in the image).

Aircraft travelling to join the final approach are being “vectored” by air traffic control. This means each aircraft is being given its own heading and altitude to allow it to intercept the final approach path (A1 in the image), while maintaining safe separation from all the other aircraft around it.

These aircraft are continuing to descend for landing under air traffic control instructions. This means that the altitude of each aircraft will vary according to how far it has left to fly before intercepting the final approach and the altitudes of other aircraft in the area. Aircraft will generally intercept the final approach at around 3,000 feet in altitude. When they are over the eastern suburbs they generally will be within the range of 6,000 to 7,500 feet in altitude.

The image below shows the actual tracks of aircraft being vectored over the eastern suburbs. These show the spread of aircraft that is created by the act of vectoring. This spread is deliberate as it is part of the noise sharing strategy set out in the Long Term Operating Plan for Sydney Airport.