Last night's reopening of the skies over the UK followed intense lobbying from an
airline industry that for years has resisted efforts by regulators to set a "safe" level of volcanic ash at which it is considered that
flights can continue, the Guardian can reveal.
What airlines had been afraid of was the potential damage to their reputation and finances in the event of one of their planes being lost due to dust after an all-clear had been announced, with a fear of legal actions arising from the deaths of all those who had been on board.
Unwillingness to grasp this nettle hampered what had been continuing discussions on the dust issue prior to the Eyjafjallajokull volcano erupting.
However, faced with losses running into hundreds of millions as the effect of Eyjafjallajokull spread and lingered into a sixth day, it was the airlines who began to call for the regulators to determine and set such a safe threshold, to avert the severe financial consequences of planes idle across Europe and passengers claiming refunds for cancelled journeys.
A source at the International Civil Aviation Organisation (ICAO) said of the history of the failure of efforts to agree a safe level: "The bottom line is that there is a huge liability issue for the industry here, so they have been super cautious on providing information. If they say it is safe, and there is an accident, they will get slaughtered."
The organisation has been trying since at least 2008 to get airlines and manufacturers to help establish a consensus on a safe concentration of volcanic ash.
In an indication of the pressure now put on air safety bodies, British Airways said hours before the UK's flights resumed that it hoped the UK's Civil Aviation Authority now had all the data necessary to lift the flight ban. Pointedly referring to the relaxation of restrictions by states such as Italy and the Netherlands, BA had said: "Despite the fact that airspace over most European countries is open, UK airspace remains effectively closed. We hope that on the basis of the data provided by the industry, the CAA will be in a position to direct National Air Traffic Services (Nats) to reopen UK airspace."
Airline sources said that a meeting this morning between the CAA, Nats, airline executives and the transport secretary, Lord Adonis, was "constructive" as safe flight corridors through the ash were discussed.
This week BA, easyJet and Virgin Atlantic have demanded a greater say in decisions on flight bans and air safety.
The perceived inconsistency of various European states' approaches to the volcano cloud has been one of the biggest complaints from airlines.
Ryanair, Europe's largest short-haul carrier, became the latest to reveal the scale of its losses, £5m a day, while the Emirates airline of Dubai warned of an "implosion" if restrictions were not lifted.
"Unless the states ... come in and bail these companies out, there won't be many carriers left," said Tim Clark, Emirates president. "You simply can't afford to shut down something the size of Europe."
Asked on BBC Newsnight about how much pressure the government had come under to lift the flight ban, Adonis said "They've obviously wanted to be able to fly their planes - of course they have - but that has not been the issue … the issue is the assessment of the safety authorities as to what is the safe way in which planes can fly when there is a presence of ash.
"The fact which has changed in the last week is we have had a volcanic eruption, and having to assess safe levels of ash within which planes can fly has been an urgent issue which the safety authorities have had to deal with. That's been what's changed over the last five days - it's not been pressure from the industry which has caused [it]."
The crucial change came when Nats announced that safety tests had shown aero engines "had increased tolerance levels in low ash density levels".
Nats spokesman Alex Bristol told Sky News: "We don't feel we have been under pressure from the government. Where the pressure has come has been to better understand the safety implications. Our first priority has been safety, and the reason we didn't simply lift the restrictions was because of our desire for safety."
According to the International
Air Transport Association (Iata), the crisis had cost carriers $200m (£130m) a day – most of it for European operators. A group of those airlines, including the association of budget airlines, urged the European Union to waive consumer legislation which imposes costs, including hotels for stranded passengers, during prolonged disruption; it was turning "a crisis into an economic catastrophe".
Going back into the history of attempts to set a safe level of ash, minutes of a Paris meeting in 2008 show the industry at odds with regulators. The ICAO meeting concluded that improved measurement techniques should allow progress "with regard to the definition of the lower limit on safe ash concentrations".
The ICAO complained it had "proven difficult to get formal aviation representation" at workshops on the issue organised by the UN's World Meteorological Organisation. It suggested "input of the aviation industry to this problem may have to be sought" through its sub-group on volcanoes, which has industry representatives. It asked several groups, including the International Air Transport Association, Iata, representing 230 airlines, to prepare reports for the volcano group's next meeting at Lima in Peru last month.
Minutes for that meeting show the industry did not deliver. "Iata informed the group about the strong efforts made in order to get representation from the industry ... but unfortunately these efforts had not been successful, to the disappointment of the group."
Herbert Puempel, chief of the WMO aeronautical meteorology division, who sits on the ICAO group, said the industry's reluctance was "fully understandable". "They have found it very difficult to come back with a single answer. If they have one number then it would be very low," he said. "The moment you set a limit then the lawyers will have a field day."
Iata said: "At the end of the day we are dependent on the airframe and engine manufacturers and their experts. We have encouraged them to participate." However, an aerospace industry source told the Guardian that any attempt to blame aircraft and engine makers was "passing the buck".