“The data has just come out for September and the cancellation rates tell the same story. On Sydney-Melbourne Jetstar cancelled 9.9 percent of flights, Virgin cancelled 9.3 percent and Qantas cancelled 7.4 percent. Interestingly, the cancellation rate for Rex was zero,” he said.

“Airlines have claimed that it’s weather and staff shortages in Air Traffic Control that are to blame. For the record, there were 17 days in September where there were no weather or air traffic issues. Yet on those days, outbound and inbound on the Sydney-Melbourne route, there were still 184 cancellations, or 52 percent of the total for the month.

“In other words, in September there was almost zero correlation between cancellations and external factors like weather or ATC issues.”

A slot is a literal time slot that allows an airline to take off at a specific airport at a particular time.

Currently, an airline can hold a time slot at an airport indefinitely as long as it flies it 80 per cent of the time, allowing carriers to cancel up to a fifth and block out rivals from the best times.

The rules are necessary because two aircraft cannot simultaneously take off on the same runway.

It’s led to accusations that major carriers are effectively gaming the system to take advantage, though both Qantas and Virgin have vehemently denied any wrongdoing.

Speaking at the conference, Culbert reiterated his long-standing calls for the 80/20 rule to be changed, saying behaviour will not change until this happens. Sydney Airport has proposed the rule be tightened to 95/5.

“In what industry is it deemed acceptable to cancel up to 1 in 5 services?” he asked. “The 80/20 rule incentivises slot hoarding, rather penalising it, and so long as the 80/20 rule remains in place, slot hoarding will continue, and passengers will pay the price.”

Culbert is stepping down as CEO of Sydney Airport at the end of the year, to be replaced by Transurban boss Scott Charlton.