Hilhorst said that council consultant MartinJenkins suggested in its recent report the idea of a new airport "should not be cast aside.
"It looks to be the most viable option."
However, MartinJenkins had not examined the potential uses for the Frankton land left vacant, Mr Hilhorst said.
"We're filling in the gaps.
"The actual benefits of moving the airport haven't been investigated at all.
"They are profound benefits."
The group is also preparing two more reports, one of which will cover alternative airport sites in the Cromwell-Tarras area.
Mr Hilhorst said there were five sites that would "meet the viability criteria", one hour from Queenstown and less than an hour from Alexandra, Cromwell and Wanaka.
When released in late July, the report would not contain the specifics of the locations "simply because that's a can of worms".
Mr Hilhorst said the group was working for the community "pro bono", and ran the risk of having its work "sidelined" by the council as a result.