The haze is clearing

Solutions for dealing effectively with the atmospheric volcanic ash problem for aviation are slowly coming into focus.

It is clear now that almost all the data that will provide best practice for operating in ash was already available in April 2010, when Mt Eyjafjallajökull erupted, grounding Europe. However, at the time that data was in the hands of scientists, not policy makers or decision makers. As usual, it took a graphic lesson from mother nature before national aviation authorities (NAAs), departments of transport and governments were prepared to listen to what the scientists had to offer. If they had known how to use the data, 98% of the flights grounded in 2010 would have flown safely.

When they did start listening, they found there was a lot to take in. Converting practical knowledge into sound policy takes understanding, and that is never instantly available.

What is happening now at the science level, is mostly about refining ash detection technology and methodology, about proving and refining the algorithms that enable the experts to define, not only where the ash is and where it is going next, but what its local concentration is. Also emerging is the understanding of which concentrations are hazardous and harmless.

Individual airlines that have to regularly deal with ash on the routes they fly had standard operating procedures determined by practical experience. The simplest example is that of British Airways, which nearly lost a Boeing 747 over Indonesia and subsequently learned that if it flew 100nm (185km) from the visible volcanic plume, it had no problems.

However, the NAAs want more than trial and error to make policy with: they want figures, they want tests, they want confidence. The rate at which the space-based and ground-based ash surveillance methodology is being refined is accelerating now it is being taken seriously. The airborne measurement and testing programme, however, has been lagging. There are only a handful of aircraft worldwide with the capability for ash surveillance and sampling.

Enter EasyJet, with an answer for Europe - fit 100 airliners based around the continent with an ash sensor developed by Norwegians and tested by Germans. That way, not only can pilots see ash ahead and avoid it, but the sampling data needed to build confidence in the total system will gradually accumulate. Who says low-cost carriers fail to think laterally?

(This article appeared as the main Flight International leader in our issue of 13 December 2011).