Sydney’s new A$5.6 billion (US$4 billion) airport will open to passengers in October after more than a decade of planning, adding red-eye flight options from Australia’s largest city as the existing hub operates under night curfew restrictions.The current airport, located closer to Sydney’s central business district, can host take-offs and landings only until 11pm and after 6am due to tough noise regulations, limiting airline scheduling options relative to other major Australian cities like...