Queenstown Airport is one of New Zealand's most difficult airports to fly into because of the area's terrain.
It is why it has never been able to use conventional radar, but now a new system is changing that.
The project at the airport has been a logistical challenge, involving solar-powered towers built to withstand hurricane force winds high above Lake Wakatipu.
Everything needed for the construction was helicoptered in, says Roger Kippenberger, Queenstown Multilat Project Manager.
"Including about 60 tonnes of concrete and the steel masts and the Portacom building," he says.
The tower is just one of 17 sites on the mountains around Queenstown that will be used to make the airport safer.
The new system, called multilateration, can be over 10 times more accurate than radar.
Queenstown has always been a notoriously difficult airport to fly into with its short, narrow runway, yet it claims to be the second busiest in the country for landings and takeoffs. And unlike New Zealand's other main airports the rugged landscape means conventional radar does not work.
Multilateration works by receiving the signals generated by aircraft at multiple sensor sites to pinpoint a plane's position.
Queenstown air traffic controllers will no longer have to rely on pilots to report where they are when they cannot see them.
They will be watching the aircraft on a screen and it means they will be able to use a new airport approach - all of which should lead to less delays for passengers.
The whole system is expected to be fully fired up by the end of 2009.