Australia's transport ministry has reiterated a call for a second airport in Sydney, pointing to a higher number of delays at the country's main gateway as evidence of its urgency.
Overall on-time performance for Australian domestic airlines was 82% for domestic departures and 80% for domestic arrivals in 2012, according to latest data from the Bureau of Infrastructure, Transport and Regional Economics (BITRE).
Sydney's on-time departures, at 80.5%, were below the national average and worse than Melbourne (84.7%) and Brisbane (82%), says the ministry. The number of flights delayed by 15 minutes or more at Sydney is predicted to double by 2025, and this will rise so that by 2035, 48% of all flights will run late.
With four out of every 10 flights within Australia coming in and out of Sydney, the country's entire network could be disrupted and the "flow on effects" will be felt in other cities, adds the ministry.
"The reality is that without extra aviation capacity through a second airport, delays at Sydney Airport are set to grow," says the transport ministry.
"The solution to handle the expected growth in aviation is simple - Sydney needs a second airport. The costs of not acting are substantial. If a second airport is not built, our national economy will suffer as congestion grows and flights and economic investment are turned away."