Wellington Airport expects to lodge a resource consent application early next year to extend its runway by around 300 metres - and it could be extended at both ends.
Initial estimates put the cost of the extension at $300 million, or $1m a metre, when the project was announced a year ago.
The airport said it would voluntarily share information it collects over the next six months with the public. The sharing process would be done by way of open days at the airport.
People would also be able to submit their views as part of the formal resource consent process.
Airport chief executive Steven Sanderson said that over the next three months engineers would investigate options to extend the runway north, south, or a combination of both.
''We will look at the environmental impacts and costs associated with both [north and south] sites.''
Wellington City Council, which owns 34 per cent of the airport, would contribute $1m towards the resource consent application. The remainder of the airport is owned by Infratil.
Sanderson said the resource consent process would help the airport nail down the cost of the runway extension, which would need external funding.
''There is not a clear business case for the airport to invest $300m. The rough order of contribution for the airport runs around $60m.''
An initial economic study showed benefits from extending the runway. A further independent study has been commissioned by the airport to delve into the economic impact for Wellington, the region, and New Zealand.
Extending the runway would enable direct long-haul flights to use Wellington Airport. Currently the additional fuel required to reach long-haul destinations means the number of passengers and cargo are restricted on flights beyond Australia.
Sanderson said it was anticipated that lighter and more fuel efficient next-generation aircraft such as the B787 and A350 would be able to use Wellington's existing runway.
However, now flying, their actual performance was not as favourable meaning they would be load restricted and not commercially viable.
''If you look at the order books that's where all of the airlines are placing their orders... and they [next generation aircraft] will be in operation for the next 15 to 20 years.''
Sanderson was also keen to dispel the story that the proximity of the Newlands Ridge would make it impossible for aircraft to safely use the runway if it was extended to the north.
He said new technology called Required Navigation Performance (RNP) enabled curved flight paths to avoid the ridge.
''There is already an RNP route out of Wellington.''
It is also used in Queenstown, and a trial is under way in Auckland, he said.
Ultimately, the navigational requirements would have to comply with the Civil Aviation Authority's rules.
Sanderson said he had already been contacted by those concerned about a runway extension, including the Hataitai Residents Association worried about visual aspects.
People were also worried about louder noise from bigger aircraft.
''What we are seeing is aircraft are getting quieter. There will be a net effect of larger aircraft with more capacity and lesser volume.''
But he said there had also been plenty of positive feedback from the business community, and the travelling public who do not want to make two or three stops to get to their long-haul destination.
By the end of the year at least nine reports would be completed as part of the airport's consent application. ''Our message is let's get all the information over the next six months. Then we will certainly have public open days.
"We will share a lot of our findings with people so they can make informed conclusions in terms of the runway extension and its effects and mitigations we would put in place.
''We will do that on our own volition to communicate with all stakeholders but particularly local residents,'' Sanderson said.
- The Dominion Post
How soon will you visit the new war memorial park?Related story: War memorial park all but completed