Dodging volcanic ash

Things are moving on.

The Icelandic volcanic ash that immobilised European aviation – and Europe’s economy – for a week in April 2010 need not have grounded us the way it did. We know that now, but at the time we didn’t. About 98% of the skies were usable, but the industry had no safe way of being sure about which bits to avoid.

That is about to change. The picture above shows partners Airbus, EasyJet, Nicarnica Aviation and Dusseldorf University of Applied Science at a briefing in Toulouse on 13 November, providing detail about the ash detection programme they are running together.

In December two years ago I visited an airstrip in Calatabiano, Sicily at the base of active volcano Mount Etna, where EasyJet and Dusseldorf University were running trials on a prototype system to allow pilots to see and avoid atmospheric volcanic ash.

The picture below shows an ultralight aircraft taking off from Calatabiano with an ash-detector pod beneath the starboard wingtip, Etna glowering in the background.

 

That was then. This is now (see below)…

 

That’s a slide displayed at the Toulouse presentation when EasyJet, Airbus and Nicarnica Aviation – partners in the AVOID (Airborne Volcanic Object Identification and Detection) test programme, at which the companies presented details to the press and the European aviation community about the proof-of-concept trials that had been completed about a week before.

The picture shows an Airbus Military A400M, loaded with a tonne of real Icelandic volcanic ash, releasing it into the atmosphere over the Bay of Biscay as it climbed in a upward spiral to create a real airborne ash-cloud about 3km across and 600ft deep.

It was a brilliant idea. The team didn’t have the time or money to travel the world waiting for an exemplar eruption that would occur just when the meteorological conditions for scientific observation and analysis were perfect, so they waited for the right conditions, and created their own ash cloud locally – but a real one in terms of the material used.

Loitering not far away were two other aircraft – an Airbus A340-300 and a Diamond DA42 diesel-powered twin.

 All three aircraft are visible here (above) as well as EasyJet’s A319.

 

The DA42′s task was to fly into the ash cloud and use its external sensors to sample the ash to check it was the same material that the A400M had dumped, and test its levels of concentration in the atmosphere.

The small twin was bristling with sensors. And since it’s not turbine-powered, its engines are safe from ash until the air filters get clogged! So it flew into the cloud – which was almost invisible to the human eye, even from close-up – and circled within it until its sampling task was complete. The crew could tell when it was in the cloud because of the rate at which its sensors were picking up ash, and they could also tell when it was approaching the cloud edges from within because the ash accumulation rate started falling.

The A340 was fitted with the AVOID pod, which is basically a smart infra-red sensor. It started rather more distant from the location at which the ash was being released, and tracked toward it.

This is the AVOID pod. It was mounted high on the forward fuselage of the A340. Nicarnica says a commercial version would not need to be external like this – it could be co-located with the embedded video cameras many airliners now have in the fin or below the nose to provide passengers with visual images.

And inside the A340, Nicarnica Aviation scientist and AVOID inventor Dr Fred Prata (see below, seated) watches the scene unfold in real time as the pod picks up pictures of the ash cloud and its concentration from about 70km distant.

And this is what they could see. Bear in mind that the concentration of the ash was extremely low, yet AVOID could not only see it clearly from up to 70km away, it could measure and display concentration levels. Analysis now going on will compare the levels detected and displayed by AVOID with the levels measured by the DA42 flying in the cloud itself. Incidentally, AVOID also showed the DA42 manoeuvring within the cloud as the A340 headed toward it.

That is my photograph of a slide on the presentation screen, so its quality is not perfect.

So how will the pilots flying commercial schedules be able to use this? Here, EasyJet demonstrates: AVOID signals can be displayed on a Class II electronic flight bag screen, in this case a Panasonic tablet computer.

But how does this ensure that the April 2010 experience is not repeated?

First, the analysis of satellite pictures showing ash drift has been improved, as has the predictive computer modelling of where the ash is, and where it is likely to drift next. The knowledge provided by these strategic tools means airlines will not launch aircraft into no-go areas.

But in the rest of the sky, possession of AVOID means pilots can skirt around ash accumulations like they do around convective cloud using weather radar.  Studies show that ash doesn’t usually fill the sky where it drifts, it tends to accumulate into clouds that pilots can navigate around.

So satellite pictures and computer modelling are the strategic tools, while AVOID is the tactical one. It completes the tool-box for aviators who need to fly when there is an ash risk.

That’s Dr Fred Prata, to my left, at the Toulouse briefing. This whole exercise began when EasyJet’s chief engineer, frustrated by the grounding in 2010, Googled atmospheric volcanic ash and discovered Fred, who had been working on the subject for years at the Norwegian Institute for Air Research. NILU then set up Nicarnica to develop and commercialise technology for the detection of volcanic ash and other airborne substances.

In 2010 Airbus became involved in the project after Airbus test pilot Manfred Birnfeld met Fred at a volcanic ash conference in Santiago, Chile. There are many active volcanoes in the Andes mountains, so South America has a real interest in this subject.

At the Toulouse briefing Airbus head of engineering Charles Champion said: “We are at the beginning of an invention which could become a useful solution for commercial aviation to prevent a large scale disruption from volcanic ash.”