Lack of planning kept airspace shut

WHEN the volcanic ash cloud covered much of Europe, the only option was to shut down the airspace, because nobody knew what else to do.

What rules there were about such an event were devised by the International Civil Aviation Organisation, a UN body, after all engines of a British Airways jumbo jet lost power when it flew through a volcanic ash cloud in Indonesia in 1982, killing all on board. It basically said that pilots should avoid volcanic ash clouds.

The other part of the exercise was a computer programme that forecast how such a cloud would move and when it would disperse. This map is in the control of the Volcanic Ash Advisory Centre based in the Met Office in London, one of several such centres around the world.

But the information missing from all this was exactly what density of volcanic ash a jet engine could cope with. Nobody knew. And because the cloud was not moving, they needed to know if it was safe to fly through any of it.

The US model was no help since they have no experience of such a large static cloud hanging over their busiest airports. They advise their airlines flying in the vicinity of such clouds on the facts of the cloud. The rest is up to the airline, but if their flight results in a crash they are liable.

So when the European Commission was called in by increasingly desperate member states on Friday last to see if they could sort out their problems, one of the things they and Eurocontrol did was to contact the aircraft and engine manufacturers. Together with all the experts a new system was worked out that divides the air into three zones — a definite no-fly zone where ash is too heavily concentrated; a 120-mile buffer zone which must be avoided; and the rest to be declared open.

This was put into force, allowing national air authorities to indicate what areas were safe and advising how to get around the unsafe parts.