Air traffic controllers at Sydney airport have told federal safety regulators they hold "grave concerns" about the airspace redesign introduced on 9 July to accommodate the new Western Sydney International airport, warning in a confidential complaint that they have "minimal confidence in their ability to handle the new airspace and procedures under normal traffic levels."

The Australian Transport Safety Bureau (ATSB) considered the complaint, filed in June by an experienced controller, and the federal government was notified of it on 20 August. The complainant stated that a large group of controllers in Sydney "hold grave concerns about the project," and that the redesign had been rushed, with "inadequate training for controllers, of all experience levels."

The warning cited roughly 1,000 pages of new training material that controllers are expected to absorb without an adequate timetable. The whistleblower also flagged existing pressure on the system from controller staff shortages, training shortfalls and experience levels — pressures that have already produced visible operational consequences at Australia's busiest airport.

Three safety incidents occurred at Sydney earlier in August. In one runway incursion, a Virgin Australia aircraft aborted takeoff after a Qantas flight began crossing the runway ahead of it. Hours earlier, on 9 August, a Jetstar aircraft narrowly avoided colliding with a Qatar Airways jet on the tarmac. That near-miss drew nationwide attention to Australia's shortage of air traffic controllers.

In its official response, the ATSB said the complainant drew a direct parallel with the United States. "The reporter is concerned there are similarities to the (air traffic controller) situation in Washington whereby the controllers were pleading with their local management for changes to be made in the months leading up to the mid-air collision," the bureau said. The reference is to the January 2025 mid-air collision between an airliner on approach to Ronald Reagan Washington National airport and a US army Black Hawk helicopter, which killed 67 people — the deadliest crash on American soil in more than two decades. In December 2025, the US government acknowledged that the Federal Aviation Administration and the army played a role in causing the accident.

The ATSB report said the complainant was "concerned that with current pressure associated with staffing and experience levels, fast-tracked training along with the multiple complex procedural changes," the Sydney Terminal Control Unit "is not ready to safely manage the new airspace changes as the training program currently stands."

The Sydney Terminal Control Unit, in its response to the complainant, said the individual "may or may not be across all the procedural or safety work that has occurred to this point." It said all new training manuals and procedures associated with the changes had been carefully developed and approved, that extra staff supervision and monitoring is in place, and that restrictions on new controllers working within the system are planned.

The Civil Aviation Safety Authority (CASA), the federal regulator, told the ATSB it is satisfied that Airservices Australia has implemented appropriate training, procedures and operational support arrangements, and promised sufficient oversight to maintain safety. "Relevant procedures and training were developed and reviewed by operational subject matter experts, standards personnel, and project teams prior to implementation," CASA said.

A spokesperson for federal transport minister Catherine King said it was appropriate that CASA had responded to the ATSB report. Notification to the federal government is the final step in the process.

The staffing problem has a quantified remediation pipeline. King said earlier in August that six controllers are currently in training, with another 15 expected to commence before the end of 2027. New rostering practices are scheduled for September, and a new simulator has been installed in Sydney to boost training capacity.

Passengers have already absorbed the operational cost: lengthy delays stemming from the incidents and the longer-term controller shortage have disrupted schedules at a airport handling the country's heaviest traffic.

With Western Sydney International's airspace redesign now live since 9 July, the dispute now turns on whether Airservices Australia's training regime and CASA's oversight can close the readiness gap the controllers describe before traffic growth compounds it.