The airport spent about $400million in the past five years and plans to spend the $2.1billion during the next five.
The substantial increase reflected an under-invested airport playing catch-up on new infrastructure, she said.
"Capacity constrains have been compounded in recent years by accelerated passenger growth and delays in project implementation."
It also reflected inflationary pressures stemming from the current construction cycle, Ms Kinnaird said.
Auckland Airport acknowledged airlines representing 80% of passengers supported the capex outlook.
Given the company only consulted larger airlines and the Board of Airlines NZ, that suggested Qantas was against the spending, because its domestic business, Jetstar, relied on a very low cost structure.Total capex through the period could total $2.9 billion as management suggested non-aeronautical capex spending rates would remain at current levels.
Forsyth Barr estimated the level of capex spend would more than double net debt to $4.3billion in 2022 from $2.1billion in 2017 — in the absence of any asset sales, Ms Kinnaird said.
In nominal terms, average revenue on a per passenger basis was expected to be $22.98 in the current financial year, rising to $23.50 by 2022. For domestic passengers, it was expected to be $5.73 this year and $6.57 in 2022. Auckland Airport was expecting total passenger numbers to rise from 19.8 million in the current financial year to 22.6 million in 2022. According to the company, its new prices for the 2018-22 financial years would target a return on investment of 6.99%.
"We believe our prices are fair and reasonable given the significant investment we are making in long-term infrastructure and our charges remain only a small fraction of the overall cost of travel," airport chief executive Adrian Littlewood said.
Among other things, the planned investment would provide three more contact gates for international aircraft, a new domestic jet terminal, the border processing area and public arrivals space would be expanded, the international check-in area would be upgraded and investment would be used for public transport, roading and walking projects.
The company also said over the next five years it would take "significant steps" towards opening a second runway it currently expected to be required by 2028. Based on an opening date of 2028, it expected earthworks to start around 2020 or 2021. If the construction of a second runway was confirmed, it would introduce a runway landing charge of $1.19 per passenger at that time.
The new prices would apply to airlines operating at Auckland Airport between July 1, 2017, and June 30, 2022.
Auckland Airport shares last traded at $7.18, down 2c. Forsyth Barr had a share target price of $6.15.
