Nelson Marlborough Rescue Helicopter pilot Tim Douglas-Clifford was one of many pilots providing help in an area where many remain without services and cut off by road.
Those helping with the work included pilots and helicopters from Helicopters Otago in Dunedin that left early yesterday.
Mr Douglas-Clifford said he was ''shocked'' by the size and number of slips on the stretch of State Highway 1 north of Kaikoura.
''Once you start seeing the slips they just grew and grew on you,'' he said.
Photographs he supplied showed mountains of rock and earth spread across the highway, train tracks tossed across the road and almost into the ocean, and a video he shot shows a massive crack heading out to sea.
He saw a train stuck on the tracks, which had ''obviously stopped just in time'' to avoid being derailed, and inland he saw whole hillsides collapsed.
He believed it would take months to open the road again, but added it was lucky the earthquake occurred when not many people were using it.
It would have been ''devastating'' if it happened during a time of peak traffic.
After the earthquake, Mr Douglas-Clifford started flying at 1am and finished at 11am, when another pilot took over.
He was tasked with flying Fire Service area commanders to Kaikoura, who were brought in to help volunteer and rural crews respond to the quake. After that he helped respond to medical emergencies.
Kevin Gale, from Helicopters Otago, said the company sent two air ambulances at 2am yesterday.
They had been on duty all day with intensive care paramedics on both machines, undertaking everything from ambulance work to winching people in and out of inaccessible areas.
Mr Gale said the pilots had been ''flying a good portion of the day and night''.
A third pilot was on the way north last night to provide back-up.
A third helicopter had left at daylight, and was working with the Fire Service and police making reconnaissance and survey flights, lifting bridge equipment into place and transporting electricity technicians. Conditions had been good for flying.
Mr Gale said he did not know how long the pilots and helicopters would be in the area.
''It's just as it comes. As long as it's required we'll keep rotating pilots through.''
It was possible more helicopters would be needed.
Two helicopters remained in Dunedin for rescue work, as the Helicopters Otago contract stipulated.
- Additional reporting by David Loughrey
