Australia's transport authorities said on Friday they were investigating what went wrong after three near-misses in less than two weeks at Sydney Airport, including two in one day.

A Virgin Australia 737 had been cleared for take-off by air traffic control on Sunday morning when the crew saw a Qantas plane crossing the runway ahead of them, the country's transport safety investigator said.

The crew brought the plane to a stop about a kilometre from the other aircraft, which had also been cleared to taxi across the runway.

Earlier in the day, a Jetstar pilot was forced to apply the brakes suddenly to avoid crashing into a Qatar Airways jet.

They came after two Qantas planes also avoided a collision on July 27 after they had been cleared for takeoff.

"I can reassure the travelling public that we will consider any organisational or systemic issues that may have contributed to these occurrences, and will do so in a comprehensive and timely manner," Transport Safety Bureau Chief Commissioner Angus Mitchell said on Friday.

"We look at all the evidence, how busy the airport was, what was the manning in the tower at the time."

Questions have also been raised as to why it took so long for the incident to be reported.

Mitchell said there had been a "supervisory or a training situation taking place" on Sunday.

"We do know, as I've mentioned before, that this is a significant, I guess, ramping up period for air services in terms of recruiting, training and qualifying air traffic controllers," he added.

"What we do know is three incidents occurred that shouldn't have occurred. We need to understand why."

Prime Minister Anthony Albanese also called for an investigation into the incidents. (AFP)




Edited by Azam Khan