Ash detector trials could help ease flight restrictions

Jason Ford

News Editor

Easyjet is to trial a volcanic ash detector on one of it Airbus aircraft, with tourists and stakeholders hoping it is deployed quickly to put an end to flight restrictions.

One such stakeholder is BAA, which is set to release its monthly traffic figures later this week.

BAA’s airports were disrupted in April because of the six-day blanket ban on flights imposed by the Civil Aviation Authority due to the volcanic ash cloud from Iceland.

BAA said that the disruption caused by the ash cost the company £28m and that further impacts are expected due to the return of flight restrictions in May.

In Berlin, Giovanni Bisignani director general and CEO the International Air Transport Association (IATA) has sounded his dismay at the impact of the volcano on his industry.

Delivering his State of the Industry address at the start of the 66th IATA Annual General Meeting and World Air Transport Summit, he said ‘April gave us a vivid picture of life without aviation. Ten million people were stranded. Hotels and convention centres were empty. Seafood and flowers rotted. And just-in-time production was delayed.

‘The volcano cost the global economy $5bn—far more than the $1.8bn of lost airline revenue. The volcano’s eruption was a wake-up call. It reminded us that without air connectivity, modern life is not possible.’

Step in Easyjet chief executive Andy Harrison who said the AVOID (Airborne Volcanic Object Identifier and Detector) system to be trialed on an Airbus A340 test aircraft would be ‘the silver bullet that will make large-scale ash disruption history.’

But will it really be that easy?

Dr Colin Brown, director of Engineering at the Institution of Mechanical Engineers welcomed the trial but sounded a note of caution. His opinions can be read here.

Similarly, Dr Thurai Rahulan, lecturer in Aeronautics at Salford University said: ‘Forward Looking Infra Red (FLIR) devices have been used in military and police aircraft since the nineties. Since they generate an image based primarily – but not exclusively – on temperature differences, hot ash particles and rocks can be detected during ejection transients.

‘The international standard atmosphere temperature variation is linear with + 15 deg C at sea level to -55 deg C at 11km altitude,’ said Rahulan. ‘My guess is that the heavier stones/rocks will fall back whilst still hot whereas the light particles in suspension will cool down quickly to ambient temperature. However, the dissipation of the remnant pocket of heat energy might be slow giving time for it to be detected by an infrared scanner. Police units are normally tuned to maximise contrast (standard or reverse video) between + 15 deg C (tarmac and countryside) and + 40 deg C (human body and cooling engines). It is best not to make too many promises until results from flight tests are compared with through-ash flight measurements by instrumented aircraft.’

He went on to add that there may be drawbacks also with the redesign of the radome and indicators on the pilot display panel. The system’s power consumption, purchase and maintenance costs and certification issues also require scrutiny.

‘In addition to the trip fuel, aircraft are required to carry additional quantities for diversions, contingencies and emergencies,’ said Dr Rahulan. ‘But bad weather already creates mass diversions occasionally and hence the radar is unlikely to lead to a chaotic situation following diversion due to volcanic ash.’

Despite the numerous caveats AVOID has attracted, its also worth applauding EasyJet for taking the step to trial the technology.

In a similar vein, The Royal Academy of Engineering Awards Dinner this evening aims to celebrate the best of British engineering achievement and innovation.

Good luck to all of our readers nominated for an award.