Entry will range from $5 to $10, to cover costs. Entry forms are available from Sport Whanganui and online at www.sportwhanganui.co.nz.
Entries close on December 5 and late entries will cost more.
The runway has to be clear by 12.30pm, before the first Air Chathams flight arrives an hour later. Air Chathams is donating return flights as prizes, and there will be other prizes as well.
A flag on the tower will be unfurled at noon, and Whanganui Mayor Hamish McDouall and a representative from Airways, New Zealand's air navigation service provider, will speak.
Guests will be able to go inside the tower after that.
The control tower was opened 57 years ago, on December 9, 1961. It was designed by Gordon Smith, who also designed the Whanganui War Memorial Centre.
It was the prototype for other provincial control towers, Henderson said, and Whanganui District Council has listed it as a heritage building.
It was decommissioned in 1989. By 2004 the council was considering demolishing it, but an aviation enthusiast, the late Owen Cantillon-Rice, started a group to refurbish it.
Eventually the interior will tell stories of the airport's past, including its history with aerial top dressing, and show video of early flights.
The work has cost $470,000 so far. Volunteers worked on the windows and roof. After that it took a long time to raise enough money to pay contractors to repair the rest of the exterior.
The biggest funders were Lotteries Environment and Heritage, the Four Regions Trust, Lion Foundation and Infinity Foundation. The council put in about 20 per cent of the total, Henderson said.