All Blacks great Richie McCaw has joined the deadly earthquake rescue efforts.

The recently retired rugby superstar is now a commercial helicopter pilot.

After a rude awakening this morning, he has been flying rescue and reconnaissance missions.

"Like everyone else, I got woken up at midnight... yeah a bit scary," he told the Herald.

At first light, he helped fly two USAR teams to Kaikoura where one person died in a collapsed house.

"From there, we took the Fire Service just north and south of Kaikoura to check out all the slips and make sure everyone was accounted for," he said.

From the air, McCaw said he saw "big cracks in the road, cracks in the side of the hills, and obviously slips".

"At one point, the railway and as way out over the sea - it had been pushed out by slips. It would not have been a nice place to be at midnight last night."

He added: "Just from a selfish point of view, it's nice to be able to fly but you'd like to be able to do it in better circumstances."