Queenstown Airport's $20m runaway plane fix

Queenstown Airport is investing millions of dollars in special cement blocks designed to crush under the weight of an aircraft to prevent a rare, but possibly catastrophic runway overshoot.

Beds of these energy-absorbing cellular cement blocks will be installed at each end of the airport's main runways at a cost of more than $20 million.

Airport board chair acting chief executive Todd Grace said the blocks were designed to safely bring an aircraft to a controlled stop with minimal damage.

"Runway overruns are rare, but the consequences can be catastrophic, so we want to do everything possible to mitigate that risk here," Grace said.

Queenstown Airport has a compliant minimum runway end safety area of 90 metres, but he said the changes would substantially increase the margin of safety, providing the same protection as a 240m safety area.

There have been 128 of these beds installed across the world including in John F. Kennedy (JFK) International Airport and London City Airport, and these had safely stopped more than 20 aircraft ranging from business jets to a Boeing 747 without fail.

Board chair Adrienne Young-Cooper said Queenstown Airport was committed to maintaining the highest standards of safety and this was the first project from their recently completed master plan.

Runway Safe had been contracted to install the beds in spring with work to be completed at night.

A Queenstown Airport spokesperson said there would be no disruption to flight schedules.

The work was expected to be finished by the end of summer.