Crack appears in Air NZ plane's windscreen during flight: 'I thought I was going to die'

Air New Zealand flight 8832 reportedly dropped altitude over the Southern Alps after a crack appeared in the plane's windscreen. File photo / Steven McNicholl

An Air New Zealand plane window that started cracking mid-flight forced the pilot to drop altitude suddenly on Sunday, leaving at least one passenger fearing for his life.

The 2pm flight 8835 from Hokitika to Christchurch suddenly dropped altitude while flying over the Southern Alps, passenger Haydn Draper told 1 News.

Draper said water cups flew up to the ceiling as the plane dropped.

"I don't mind a bit of turbulence on a plane, it can be fun, but I thought I was going to die," he told 1 News.

Passengers then saw the plane's windscreen was cracked when they were on the tarmac, but those who filmed or took photos were stopped by staff and told to delete them, 1 News reported.

Draper managed to keep his footage, which clearly shows big cracks in one windscreen pane.

An Air NZ spokesperson told the Herald that flight NZ8835 had "experienced cracking in a layer of its windscreen while enroute to Christchurch yesterday afternoon".

"The pilot followed standard operating procedure and reduced altitude after the cracking developed," the spokesperson said.

"An aircraft windscreen is made up of layers of separate panes of glass - therefore cracking in one layer in no way risked the integrity of the windscreen. At no time was there any risk to passengers or crew and the aircraft landed in Christchurch without incident."

Engineers have replaced the windscreen and the aircraft is back in service.

A spokeperson also told 1News that passengers had been asked to delete their footage because of restrictions around using mobile phones on the tarmac.