Two Air New Zealand night flights to Tonga were postponed over the weekend due to the potential hazard presented by a plume of volcanic ash and steam coming from the continuing Hunga Ha'apai eruption close to Tongatapu.

Sue Gardiner, the Air New Zealand agent in Tonga, said that day flights were unaffected but there was concern over the night arrivals because the pilots could not see the ash clearly at night. The plume coming out of the volcano was the main concern, because if a plane flew into it, it could be serious.

The Friday night flight NZ66 out of Auckland that was due to arrive at 1:00 am Saturday was postponed and it arrived at 11:30 am the same morning.

"I was on the flight and as we flew over the area of Hunga Ha'apai it appeared there was a little steam coming out," said Sue. "But then at 2:30 pm we had the met office report saying there was more volcanic activity in the area, so we decided to postpone the Saturday evening flight.

Sue said that on Friday evening they had requested permission for a Sunday flight from the Prime Minister, and they were told that, "he said, No".

Sue said that because the PM's staff could not be contacted they decided to go through the Minister of Transport, Paul Karalus, who was in New Zealand. "My staff got his cell number and I called him in the evening. We asked Paul to request a Sunday flight to minimise disruption to passengers and cargo, and he spoke to the Prime Minister on my behalf. He called back the same evening to say, no, the Prime Minister could not do it."

The reason why we wanted the Prime Minister to approve a Sunday flight was to minimise disruption to both passengers and cargo, she stressed.

Perishable

"We had four and a half tonnes of fresh perishable cargo - all fish exports that was packed and ready to go out on Saturday to the USA, Japan and New Zealand. But this cargo loses its value when it is delayed.

"We were unable to discuss the details of this problem with the Prime Minister because the current law would not allow the Sunday flight in this situation."

"I know Tonga does not allow Sunday flights but I just thought I would try anyway because it is so important for our passengers and exporters."

Therefore Saturday night flight that was due in at 7:30 pm was cancelled and this morning's flight was upgraded to a bigger aircraft, a 767, to replace it.

Sue said that Air New Zealand would reassess the situation before each flight this week. The next scheduled night flight is the Tonga to Apia to Los Angles flight on Tuesday evening.

The Hunga Ha'apai eruption started on March 17 and is located about 62 kilometres to the north of Nuku'alofa on Tongatapu. The eruption has appeared to be decreasing over the weekend