Ash plumes ground some aircraft again

The ash cloud that has caused travel chaos around the globe is moving slower than expected over New Zealand.

Civil Aviation Authority (CAA) meteorological manager Peter Lechner said the cloud was entering New Zealand airspace and was due to cover the country this evening.

He said it will be hovering around 20,000 feet and is moving slower than expected.

Lechner said it could take two to three days to pass.

The ash, from the Puyehue-Cordon Caulle volcano, has forced Qantas and Jetstar to suspend flights.

Qantas has suspended all trans-Tasman services until further notice and Jetstar has cancelled all trans-Tasman flights and domestic New Zealand flights for the rest of the day.

Jetstar will provide an update on tomorrow's services this evening.

Pacific Blue, Aerolineas Argentinas, and Lan Chile also cancelled services yesterday.

Lechner said it was possible the cloud would lap the globe and cross over New Zealand a third time.

"It will disperse eventually - the dispersion process is underway but whether it comes around for a third time we can't tell yet."

When the cloud did disperse, it would do so horizontally, stretching out rather than falling through the atmosphere, Lechner said.

Last week Air New Zealand introduced more rigorous inspections of its planes because of the ash.

A spokesman said the airline adopted similar measures to those taken when the Iceland volcano erupted in April last year, by randomly checking aircraft for ash.

In addition to the regular plane checks before and after every flight, Air New Zealand would randomly inspect the engines with cameras.

"It's what every airline should be doing when you've got circumstances like this, just checking there is no ash around, and all the aircraft have been coming back clear."

He said eight of about 70 domestic planes were checked for ash at Auckland and Christchurch last week.

The Puyehue-Cordon Caulle volcano began erupting on June 4, belching tonnes of ash into the atmosphere and on to neighbouring Argentina.

- Dominion Post and Stuff.co.nz