If a flight is delayed or cancelled, what are your rights?

However in this case the delay was caused by problems with air traffic control systems. Even under the generous compensation that the EU extends to air passengers who suffer delays, air traffic control issues are classed as an "Extraordinary Circumstance", and the air carrier is not obliged to pay compensation.

Ultimately, this comes down to a failure on the part of Airservices Australia (AsA) the government-owned air navigation service provider responsible for civil aviation air traffic control, which blamed the disruptions on a software failure.

In a statement released two days after the outage, an Airservices spokesperson said "The root cause of the fault is under investigation. Once the cause is clearly understood corrective action will be developed to improve system resilience."

Regardless of where the fault in the system lies, what the outage reveals is that there is no backup system. Most modern air traffic control systems have full redundancy to allow air traffic control to maintain normal operations if the frontline operating system is compromised, but in Australia a software failure can bring our air traffic control system to its knees, and that's because an organisation isn't doing its job.

As noted by Jayson Westbury, CEO of the Australian Federation of Travel Agents: "it is hard to believe that in a modern 2017 world that a critical piece of infrastructure like power and a software feed to control aircraft movements could go down for extended period of time. And if so, that there is not a robust redundancy system in place and ready to go."

Apart from the inconvenient fact of passenger delays, a dysfunctional air traffic control system is not a safe air traffic control system.

Sources within the industry are pointing the finger of blame at cuts within Airservices Australia, and rumblings at Airservices Australia, suggest that all is not well within the organisation. Signs point to a disconnect between managers and those at the coalface, and that includes air traffic controllers.

Under a cost-cutting exercise that goes by the quaint counterfeit of the Accelerate program, AsA has had a net loss of more than 700 staff. Despite AsA's insistence that the cuts only affected backroom support staff and not frontline workers, those made redundant include safety specialists and flight simulator training operators, and AsA insiders have warned that the cuts pose a risk to air safety.

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Warning signs emerged from the severe thunderstorm that hit Melbourne on 29 December 2016, causing incoming aircraft to maintain a holding pattern over the city. Storms that disrupt air traffic are not unusual, but what was remarkable in this instance was what seemed to be panic at AsA, underlining the effects of the staff cuts.

According to a leaked email from one senior manager to colleagues: "We barely pulled through with five trained staff."

Other email exchanges between senior managers in the ASA's National Operations Centre described a system critically compromised, with staff reductions as the implied cause.

"This is synonymous with the phrase "flying blind' or "leaping before you look"; in an organisation whose primary focus is "safety" this kind of attitude is totally appalling," and "attempting a night like tonight with only two on shift is sheer lunacy."

In the wake of the storm at Melbourne Airport Senator Nick Xenophon demanded an immediate halt to AsA's retrenchments until an independent investigation was conducted. The senator has been calling for an investigation into the operation of ASA for several years, and it seems his latest demand met with the same result - a deafening silence from the authorities charged with maintaining safety in our skies.

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