A new report into the proposed Wanaka Airport expansion says it would need more than three million passenger movements a year to ensure a return on investment.
The report was commissioned by the Wanaka Stakeholders Group to assess the activity levels that may result from the proposed $400 million investment.
Report author Richard Somerville said passenger jets would have to take off and land every 10 minutes during a 12-hour day to cover costs and ensure an acceptable return rate.
"The objective of this work was to calculate the level of commercial aviation activity, which should follow from an investment of this size," he said in the report.
"The analysis concludes that a market return on $400 million requires an annual throughput of 3.14 million passengers in order to cover costs and provide a commercial return in line with broadly similar commercial airport operations."
That translated to more than 500 flights per week, carrying an average of 120 passengers.
The proposed investment was discussed by the Queenstown Airport Corporation earlier this year, he said.
"This would appear to be a reasonable cost assumption to create a jet-capable airport, allowing for a 1900m long jet capable runway with safety margins at either end, and then airport infrastructure including terminal, control tower and electronics, Mr Somerville said.
The report did not review the potential financial outcomes from the investment.
Last year, about 2.2 million passenger arrivals and departures were recorded at Queenstown Airport.
Airline pilot and Wanaka resident Terry Hetherington said the report's figures meant the Wanaka Airport would be busier than the current Queenstown Airport.
But he said the figures weren't surprising because such a significant investment needed to generate a good return.
He expected the airport would operate over 16 hour days, meaning one flight every 13 minutes.
There was increasing community concern about the future of their town if the airport expanded significantly, Mr Hetherington said.
"It's massive for Wanaka community. We don't have the infrastructure in the town and the planning for that level of infrastructure, the council hasn't done any planning towards that.
"It will change Wanaka community or change Wanaka forever."
Wanaka Stakeholders Group chair Michael Ross said his group had been raising concerns around this development for nearly a year.
He said the Queenstown Airport Corporation had projections of numbers tripling over the next 15 to 20 years and "clearly have an expectation to grow those numbers over time."
He said the group was not against growth in the region.
"Growth is not a problem for us. We are blessed with the fastest growing activity in the whole of New Zealand. It's not as though we need more growth.
"Some are saying it wouldn't hurt if the tourism visitor numbers levelled off a bit to give us a chance to recover."
Queenstown Lakes District Council referred questions to Queenstown Airport.
Queenstown Airport response
Queenstown Airport Corporation chief executive Colin Keel said the analysis was commissioned to support opposition of development of the Wanaka Airport.
"QAC was not contacted by Mr Somerville prior to the analysis being shared publicly. QAC does not propose to comment on the fundamentally flawed analysis except to say the quality of any analysis depends on the accuracy and reasonableness of the underlying assumption," he said.
The assumptions did not reflect how the corporation would proceed and grossly exaggerated any likely outcome, Mr Keel said.
Any investment would be spread over a 25-year plus period and airport revenues were not solely based on passenger activity, he said.
"QAC will wait for QLDC to undertake its economic and social impact assessments and share the district spatial plan being developed with Government before providing more detail on any future airport development planning."