Australian air-safety investigators are examining traffic controller fatigue and staffing levels after a Qantas Airways Ltd jet was cleared to cross a runway while another jet was landing, one of a series of recent lapses at the country’s busiest airport.

That incident, one of 11 recorded there in July and August, was given the highest severity rating by the Australian Transport Safety Bureau. It was the first of that level at Sydney Airport and only the third at a major Australian airport since 2003.

Less than two weeks later, a Virgin Australia jet was forced to abandon its takeoff after another Qantas plane began crossing ahead of it. Later that day, a Jetstar plane had to brake suddenly while taxiing to avoid a Qatar Airways jet being towed nearby.

The spate of near-misses shines a spotlight on a chronic shortage of air traffic controllers at Sydney Airport. While the ATSB stressed it has yet to determine whether staffing factors directly contributed to any of the incidents, air traffic control involvement in each incident is still being examined.  

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“Staff resourcing within Sydney Tower at the time of many of the occurrences has emerged as a recurring area of inquiry,” ATSB Chief Commissioner Angus Mitchell said in a statement Wednesday.

“These investigations will look to understand the significance of staff resourcing pressures within the tower, specifically, the practice of combining operational roles, the routine reliance on overtime to fill shifts, and training or supervision activities being conducted alongside operational duties,” Mitchell said.

The preliminary reports said roster modeling by Airservices, which provides Australia’s air traffic services, predicted elevated fatigue risks for staff during many of the occurrences.

Staffing pressures at Sydney’s control tower have become so severe that a whistleblower told authorities in June that short-handed workers held “grave concerns” about safety. The experienced air traffic controller drew comparisons with the way controllers near Washington pleaded for changes in the months before a midair collision that killed 67 people in January 2025.

READ MORE: Sydney air traffic controllers warn of grave safety concerns

Workers inside Sydney Airport’s control tower often struggle to fill shifts on the roster, and the ranks are so thin that controllers sometimes work 10 days straight without a break, according to their union. The system relies on people doing significant overtime and results in delayed flights if workers can’t fill the gaps.

Qantas Chief Executive Officer Vanessa Hudson last month called for the staffing issues to be fixed, saying tens of thousands of passengers are being affected by flight delays.

The Australian government on Wednesday announced the establishment of a panel that’s being asked to ensure that Airservices will improve its services. The company needs to “address challenges including air traffic control workforce planning, recruitment, training, roster resilience and system improvements,” the government said.