Radar fault grounds Bay flights

Hawke's Bay resident Americans' Sarah and Doug Mason wait at Hawke's Bay Airport for their connecting flight to Auckland hopeful that they will catch their flight to visit family in USA.

Flights were disrupted in and out of Hawke's Bay as domestic flights were cancelled in the aftermath of a radar fault which grounded planes across New Zealand.

At 2.40pm on Tuesday, an "internal network failure" caused all flights to be grounded until about 4pm.

Air New Zealand said about 160 of its international and domestic flights were disrupted, with passengers likely to experience delays.

A Puketapu couple flying to Seattle to visit their children will have likely missed their connecting international flight as a result of the glitch.

Sarah and Doug Mason were scheduled to fly out of Napier at 4.10pm to catch their 6.25pm flight out of Auckland.

"We are starting to stress a bit now," Mrs Mason said.

The pair paid extra for seats with more leg room, which they did not want to lose.

"We don't want to end up in the middle or not together," Mr Mason said.

After almost an hour's delay there was still no sign of boarding.

"We only have 10 days as it is, just enough time to see the kids," he said.

Some would-be passengers took to social media to vent their frustration.

Victoria Carter tweeted just after 5pm that she gave up queuing to change her flight at Hawke's Bay airport.

The New Zealand Air Line Pilots' Association spokeswoman Lisa Williams said pilots flying at the time of the fault would have lost all radar communication.

"It is an extremely rare event."

Airways New Zealand reported the radar problem was partially fixed at 4pm and was completely operational again at 4.30pm. The backlog was expected to cause further delays.