New Zealand pilots are shocked by revelations that large chunks of concrete have broken off Auckland Airport's runway and say they pose a serious safety threat.

"This is extremely worrying news as runway debris can cause a range of issues for aircraft, such as a punctured fuel tank or engine failure. We are dealing with a very serious situation here and one that the airport company has been aware of for a very long time,'' said NZ Airline Pilots Association (NZALPA) president Andrew Ridling.

He is calling for an urgent escalation of steps to fix the problem and Government intervention if necessary.

"NZALPA's focus is safety - we make no apologies for that. We can no longer stand aside and wait for the right thing to happen. We have moved past that point," said Ridling a Boeing 787 captain.


He said in a worst case debris on the runway could lead to a tragedy similar to the Concorde crash in 2000 where a metal part from another plane on the runway at Paris ruptured a fuel tank in the supersonic aircraft.

Overnight the International Federation of Air Line Pilots sent out a safety bulletin warning its members to ensure they have contingencies for operating at Auckland.

"As these runway closures are not planned and are unable to be forecast, it is suggested that pilots should always carry a technical alternate for Auckland. Alternatively, consider carrying a minimum of 20 minutes extra holding fuel for arrival at Auckland," the Canada-based federation has warned its membership of more than 100,000 pilots.

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The bulletin follows yesterday's second short notice closure of the runway in two weeks because of debris on it. Flights had to be diverted in both cases. These cost airlines up to $100,000 for a widebody plane that has to fly to another city.

Ridling said there had been consultation and plans but action was needed now.

He welcomed the just-announced review by the airport company but said that a three-week delay before review results were known was concerning.

"The review also needs to be forward looking. We can't let this be about funding, or stop to argue whether the airport company has properly prioritised runway planning and maintenance.''


He said NZALPA couldn't allow the safety of pilots and of the travelling public to be put at risk in this way.

''New Zealanders expect more of their airport companies.''

The federation said the runway was deteriorating at a faster rate recently and there has been an increased risk of foreign object debris (FOD) damage.

Pieces of broken concrete up to 30cm by 30cm and 12cm thick have been reported

An airport spokeswoman said safety and security of its operation was its top priority.

''We have no tolerance for anything which may compromise this.''

Transport minister Phil Twyford's office said the matter was an operational issue for Auckland Airport but National's aviation spokesman Brett Hudson said the company needed to ensure the runway was functioning and safe.

If a regulator became involved it should be focused on a smooth investigation into what has gone wrong and help Auckland Airport address any issues from its inquiry.

The Civil Aviation Authority oversees safety of the runway and a spokesman said that although the disruptions were ''not ideal'' but it was comfortable that required contingency activities have been implemented by the airport.

The federation safety bulletin says the runway has been deteriorating over the past few years and there had been 15 short notice closures. The airport says only four in the past two years had been due to runway maintenance.

While the airport company has not released details of the problem, including the scale of repairs and where damage is occurring, the federation bulletin says large scale work is planned including replacement of the concrete slabs near touchdown zones.

"However, this work will not begin until later this year and will take some months to complete."

Auckland Airport, the largest and busiest airport in New Zealand, has been forced to close the runway for urgent maintenance twice in the two weeks.
Auckland Airport, the largest and busiest airport in New Zealand, has been forced to close the runway for urgent maintenance twice in the two weeks.

The bulletin says that because the airport has just one runway there is no contingency when it is closed at short notice.

This increased the risk when flying to Auckland without an alternative.

The runway closures due to defects in the runway surface alone have averaged 15 minutes over the past two years.

This trend suggests the runway closure time is increasing, ranging from 10-40 minutes.

Ridling said there were about 280 large slabs at the northern end of the runway which had been laid nearly 30 years ago and many were being slammed by large aircraft whose sophisticated navigation equipment meant they touched down in the same spot.

An airport spokesman said it will carry out an immediate formal review over the next three weeks.

''While the two recent closures were unrelated, Auckland Airport recognises they have
occurred in close succession with an impact on travellers and our airline partners.''

There was a current programme of planned maintenance for the runway, which includes
an annual slab replacement programme.

''Our review will also assess whether or not this programme of work should be adjusted,'' said the spokesman.

Work being done on on the runway yesterday. Photo / Supplied
Work being done on on the runway yesterday. Photo / Supplied

The review would also assess the speed of its response to reopen the runway yesterday.

''A number of flights were diverted or delayed yesterday, and we are very sorry for
inconvenience caused to travellers,'' said the spokesman.

The airport is required to physically inspect the runway 4 times in every 24-
hour period to maintain its Civil Aviation Operating Certificate.

''On occasion, Auckland Airport will temporarily close the runway outside the planned closure windows to allow closer inspection of a particular area, to remove FOD and/or to undertake maintenance if required.''

Auckland Council has a 22.4 per cent stake in the airport and Auckland mayor Phil Goff said he had spoken to the company's chief executive Adrian Littlewood.

''The unexpected closure of the airport due to maintenance issues and disruption to travellers affected by that are a concern to me.''

He said he had been assured the formal investigation would start ''forthwith.''

Wide body aircraft have take-off speeds of around 300kph. They land at speeds of about 270kph. A full load wide-body aircraft can weigh around 360 tonnes, depending on cargo load and fuel.

An airport spokeswoman said there currently no restrictions on aircraft using the runway.

There are approximately 180,000 flights per year and 500 flights per day through the airport.