Sydney Airport came close to completely shutting down take-offs on the afternoon of Friday September 12, when staff illness, on top of longstanding shortages left only a skeleton crew of air traffic controllers (ATCs) on duty.

According to the Sydney Morning Herald, Airservices Australia (ASA), the government-owned entity managing air traffic control, was forced to implement a departure limit between 10 a.m. and 11 p.m., allowing just 15 takeoffs per hour instead of the typical 60.

Even with these restrictions in place, the shortage of staff was so acute that ASA anticipated it would need to halt departures entirely from 3:30–4 p.m., to allow ATCs to take a mandatory break. This was narrowly averted with just an hour to spare, when an off-duty controller was eventually found to cover the gap.

The episode underscored that air traffic control operations covering Australia’s busiest airspace run perilously close to collapse as a matter of routine. The implications are not just costly and inconvenient delays for passengers and airlines, but the potential for a serious accident. Each ATC is responsible for coordinating multiple aircraft, most carrying hundreds of passengers, at once.

ASA employs around 1,050 controllers nationwide, down by some 20 percent from more than 1,300 in 2019. Over the same period total aircraft movements across the country have declined by just 6.5 percent.

In response to Friday’s incident an ASA spokesman said they expected 85 additional air traffic controllers this year to “add further depth to our rosters,” but this is only a fraction of the shortfall.

Peter McGuane, secretary of Civil Air, the union that represents controllers, said there was a worldwide shortage of controllers that was disrupting airports in cases where staff were unavailable due to illness.

The reality is that in Australia, as in many parts of the world, this shortage is the product of government and aviation authority cost cutting, which was accelerated in the first years of the COVID-19 pandemic.

In 2021, ASA slashed its workforce by 14 percent by implementing a retirement incentive scheme, which was taken up by 140 controllers aged between 56 and 65.

While a small number of new controllers have since been recruited, many are only qualified to control a particular sector of air space or work one position in a tower, unlike the majority of the controllers pushed to retire, who were trained and licensed to cover numerous roles, according to Civil Air.

Becoming a controller can take between 18 months and two years of training, combining classroom lessons with practice using flight simulators. After this, trainees work three to six months under supervision before they can apply for an ATC licence.

In December 2022, the Australian Transport Safety Bureau (ATSB) noted that it had received “a large number” of reports from ATCs to REPCON, the investigator’s confidential reporting system, over the preceding four months, including 15 from Sydney. “By way of comparison,” the ATSB noted, “REPCON has received one report relating to Sydney in the past 5 years.”

One controller wrote: “ATC is severely understaffed. It’s been this way, but functional for years. However, the last 3 months have been particularly bad. The Retirement Incentive Scheme (RIS) that ASA offered last year has taken us to unprecedented levels of staffing and is pushing the system way beyond its limit.”

Another warned: “In my [redacted] years on the job I can’t think of a more dangerous situation than this.”

Another concluded: “Our only way out of this mess is to get more staff. Quite frankly I am apprehensive about continuing to work.”

ASA responded to these concerns with vehement denial: “The reports imply that the Sydney TCU [Terminal Control Unit] does not have sufficient operational ATCs to provide the necessary service. This is not correct. Our workforce plan states the mature number of ATCs for Sydney TCU is 47. Currently there are 47 operational ATCs employed at the Sydney TCU with up to 13 required to staff the TCU on any one shift.”

But, just two paragraphs on, ASA contradictorily acknowledged that there had been “occurrences of late-notice, unplanned absences that cannot be covered,” resulting in “increased overtime shifts.”

As a result of ASA’s self-imposed staffing crisis, overtime has become a routine aspect of ATC work. Earlier this year, the Herald Sun reported widespread burnout and safety risks due to ATCs being regularly asked to work overtime.

Civil Air told the newspaper some workers had done more than 800 hours of overtime in a year, and that there was a “sharp uptick” of workers leaving for international air service providers.

The union warned, “high levels of fatigue have a severe negative impact on human performance and the quality of decision making… The consequences of impaired decision making could be catastrophic.”

Airservices responded to the burnout reports by stating that its overtime requests “are in line with the principles of rostering in our ATC Enterprise Agreement [EA].” This highlights that, despite Civil Air crying foul, the union bears central responsibility for enforcing worsening conditions for their members in line with the demands of ASA and the airlines.

The current agreement was pushed through by Civil Air last year without industrial action, despite an overwhelming strike vote by ATCs, their first in more than two decades. The deal that was rammed through contained a nominal pay rise of just 11.2 percent over three years, far short of what was needed to keep up with the soaring cost of living and recoup past losses, including under the previous union-management deal, which locked in 2 percent per annum pay increases, while official inflation soared as high as 7.8 percent.

Under the existing EA, controllers have “an obligation to work a reasonable amount of additional hours where it is necessary to meet operational requirements.” Workers are technically allowed to refuse on fatigue or safety grounds, but Airservices has the power to demand an explanation and reprimand workers, effectively pressuring them to accept this mandatory overtime.

Controllers are entitled to a break every 2–3 hours, but these breaks can be denied in “extraordinary circumstances,” such as when ASA cannot fill a shift at short notice.

In the wake of the near shut down at Sydney, some in the corporate press have pointed the finger at ATCs’ supposed right to “unlimited” sick leave. In fact, while technically entitled to take sick leave “as required”—in recognition of the serious potential consequences of controllers working while impaired by illness or medication—controllers who take 15 days or more of sick leave in a 12-month period can be subjected to punitive management reviews.

The September 12 episode shows how close routine operations are to breaking point. With staff so heavily cut, even minor absences put huge strain on those left at work and can throw the system into crisis.

ASA’s dangerous cost-cutting is not an accident. It is a direct result of the corporatisation of the agency—effectively privatisation by stealth—meaning it is required to operate as a business. Its entire funding comes from charges levied on the airlines, meaning its priorities are shaped by the profit interests of the industry it serves rather than the safety of passengers and crew.

To end chronic staffing shortages and overwork, provide decent wages and conditions for controllers and prevent disaster in the skies, a fight must be taken up to halt and reverse the privatisation of air traffic control. This should be connected to a broader struggle against the capitalist system and the subordination of human need to the profit demands of big business.

The alternative is a fight by the working class for socialism, under which critical public infrastructure and industries, including the whole aviation sector, are placed under democratic workers’ control and public ownership.