"Further coastal assessments were conducted on the likely inshore effects of the proposed runway extension and the wave focusing structure, as well as the effects of sea level rise on the runway extension."
"We are pleased to advise that the inshore effects are expected to be within the existing seasonal variations that occur and the runway will be resilient to the effects of sea level rise."
Sanderson said cost-benefit analysis showed a benefit-cost ratio to the country of 2.3 and a net benefit to investment ratio of 7.6.
The two councils will undertake completeness checks and determine whether any further information is required, the airline said, with public notification and formal submissions requested in June.
The airport is looking for its application to be heard in the Environment Court as soon as possible.
Airlines who would benefit from the extended runway would need a major hub in Asia or North America as the consents sought would enable direct long-haul services from Wellington to those destinations.
Sanderson said it was not surprising Air New Zealand and Qantas Airways have both said they wouldn't use the runway, as they don't have hubs in those locations, and the viability of the plan did not depend on their support.
The airport announced yesterday it was looking at selling up to $75 million of seven-year bonds. It is undertaking extensive upgrades, adding an eight-storey carpark building, improving its international arrivals area and building an on-site hotel as well as extending its terminal.