Senior staff at Christchurch International Airport were given satellite phones just hours before the 7.1-magnitude quake rocked the South Island city – technology that helped isolated managers cope.

Speaking at the NZ Airports Conference, Queenstown-based businessman and Christchurch International Airport chief Jim Boult said it was dark and quiet at 4.30am on September 4.

At 4.35am, the quake shook the airport, the control tower "swayed back and forth like a pendulum" and the initial rumble lasted for 49 seconds.

Senior staff arrived at the emergency operations centre to find the building's ceilings down, windows smashed and live wires dangling.

In May, the airport hired a contractor to simulate a disaster, a major fire that struck an aircraft hangar and led to the closure of the domestic terminal for five months.

Mr Boult said some of the simulation was prophetic as staff brainstormed about how to cope if the emergency operations centre were out of action and if central communications were down.

The day before the quake, senior staff were given satellite phones.

"I personally concluded that my satellite phone was likely to be an expensive luxury I was unlikely ever to use. How wrong I could be.

"Landlines had failed early in the piece and the volume of cellphone traffic, together with power failure to the cellphone towers, quickly showed us the value of satellite phones." Satellite Internet Servicesource: www.stuff.co.nz