IAA to refine ash safety restrictions

The Irish Aviation Authority said today it plans to refine its safety model in relation to volcanic ash with a view to freeing up more air space.

The IAA’s Eamonn Brennan said new restrictions, based on data from tests and analyses of aircraft operating in and around the ash plume over the last four weeks, would allow for a further reduction in the no-fly buffer zone, which is currently set at 60 kilometres.

Details of the revised restrictions were being finalised by the IAA in consultation with other European aviation authorities in conjunction with airlines and aircraft manufacturers, he said.

“What we have been doing in recent days is examining data from test flights and practical operations to see if we can refine the model further with a view to making some changes to the way we operate around the volcano,” Mr Brennan said.

“The remodelling will depend on the aircraft and the engine type,” he said.

Data from test flights in and around the ash plume and from 300,000 flights hours taken from aircraft operating in low ash areas over the last four weeks has provided significant information to aviation authorities on the safety tolerances of aircraft engines, he said.

The IAA has been criticised for relying too heavily on the VAAC (the UK Met Office’s Volcanic Ash Advisory Centre) model for evaluating ash density.

Several airlines, including Aer Lingus and Ryanair, have called for the adoption of a US-style model which establishes small no-fly zones around volcanoes.

But the IAA insists it bases its restrictions on multiple information sources and that models used in other continents were not apt for conditions here.

Mr Brennan said Iceland’s Eyjafjallajökull volcano was still emitting ash to a height of about 23,000 – 29,000 feet.

He said UK airports would be particularly badly hit today, as a 700 mile-long cloud was drifting through its airspace.

However, he said: “The outlook for the coming days is positive and the IAA does not anticipate any further restrictions relating to volcanic ash at Irish airports for at least the next 48 hours.”