The decisions that led to the costly shambles of Europe's airspace being closed for so long go back years.
Examining the protocol followed, the agencies involved and the resources at their disposal, it seems it wasn't volcanic ash that brought the air industry to its knees but decades of neglect, underfunding, poor planning and layers of bureaucracy behind the Government and Europe-wide response.
This, despite the fact that the ink had barely dried on an international contingency plan drawn up by the ICAO in September 2009.
The disaster may have been natural, but the mishandling was wholly man-made. So what went wrong, and why?
As the ash began creeping from Iceland to the UK the first people in the hot seat were not the air traffic controllers but eight scientists in the Met Office's London Volcano Ash Advisory Centre (LVAAC).
These specialists, called in only on an emergency basis, provide the aviation industry with forecasts on the spread of the ash and warn pilots of where it is unsafe to fly.
As they ran computer models, it seemed first the northern part and then all of the UK was going to be covered by the cloud. Yet closing down airspace, or even advising it, was not their job. They could only pass the forecasts on to NATS.
At the start of an eruption little hard data is available, and it was at this very early stage that things started to go wrong. For while computer ash dispersion simulations have good short-term accuracy, modelling errors build up and they get less and less reliable.
And models cannot give the allimportant detail of particle density which determines if it is safe to fly. Satellites and ground-based equipment can fill in some gaps but the results are unreliable. To get the detail required teams have to fly up into the path of the dust in specially equipped aircraft and collect physical evidence.
Yet here what happened and the ICAO protocol start to diverge. The UNorganisation recommends three clear phases of response: Alerting, Reactive and Proactive.
Nowhere does it suggest closing airspace completely - rather it talks of rerouting flights and a pragmatic approach based on continued measurement of ash levels.
The problem was a lack of data needed for a true judgment. In the Second World War the RAF had a large fleet of aircraft which could sample volcanic dust. This was whittled down until it flew its last meteorological flight in 1963.
There were still air-sampling V-Bombers, to measure nuclear fallout. But after these were retired by 1980 the RAF had only an adapted Canberra bomber and a Hercules transport, nicknamed 'Snoopy' by its crew.
But the Canberra was axed and in 2001 the Snoopy sold off. Decades of cuts had reduced the UK to the Met Office's two planes.
The resulting lack of data in the crisis and the difficulty of navigating through manufacturers' design parameters led the authorities to take the 'easy' option - setting an ash density safety threshold of zero.
It is hard to square this reality with Civil Aviation Authority chief executive Andrew Haines's assertion that Britain 'led the way' establishing the new ash safety threshold that led to the ban being lifted.
Arguably, the safety threshold announced on Tuesday was not new, it was merely the first to be formally established.
On Friday, CAA chairman Dame Deirdre Hutton reiterated the claim that the Association 'led the way across Europe' in an article attempting to explain why it took six days to reopen the skies, citing the engine failure of the BA flight captained by Eric Moody in 1982.
She implied this led to 'unequivocal guidance from manufacturers' that aircraft encountering volcanic ash must 'AVOID AVOID AVOID'.
But the BA incident would be very unlikely to happen now because a change of procedure - engines would be throttled back and the craft put into a descending turn, in contrast to what Captain Moody did, at the time understandably - has significantly reduced the risk of catastrophic engine failure.
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