From an unknown blog:
As the crisis in European aviation continues, increasing numbers of questions are being asked about whether the disruption is necessary, as I discussed yesterday. It would be tempting to think that the closure of Europe’s skies has been caused by the unprecedented nature of the volcanic eruption. That is not necessarily true.
A meeting of the International Civil Aviation Organisation European and North Atlantic Office on 1st June 2005 discussed the issue of “Volcanic Ash and its Danger to International Civil Aviation”.
The media have been speculating that the nightmare scenario is if the current volcanic eruption in Iceland were to spread to the much larger Katla volcano. In fact, a study was carried out in 2002 that simulated the effects of such an eruption. Those meeting notes describe the outcome:
An article written by Thomas Grindle and Frank Buchanan jr, which was published in the ICAO Journal (Nr 2, 2002), provided a clear account of the effects that ash clouds could have on aircraft operations…
It was noted that up to 262 flights per day could be directly affected by a volcanic eruption or 71% of the total number of aircraft flying in Reykjavik control area. Of those, up to 99 can be airborne during the first 30 minutes of the eruption. Scottish area control centre has most of the airborne flights that are affected in their area during the first minutes but they are quickly shifted to Reykjavik control area if no changes are made. The average increase due to rerouting is 24-30 NM. The change in the number of flights, with and without an eruption, in separate control areas was analysed and revealed that there is a shift of traffic from the Reykjavik control area into the Shanwick area. Other areas have very similar traffic numbers for both scenarios. The rerouting process showed that additional aircraft would be affected, not directly by the eruption, but by aircraft being rerouted. Up to 44 aircraft could be affected in this way. In addition to this the total number of aircraft affected, in one way or the other, can be as high as 82%.
In other words, a limited impact in the vicinity of the eruption.
But of course, that was just a simulation. What about a real eruption?
Well, this discussion took place against the background of the eruption of another Icelandic volcano, Grimsvotn, in November 2004.
The meeting notes catalogue the impact of that eruption:
At least one airline cancelled a flight from New York to Moscow and several airlines were re-routed or cancelled.
So that was a much smaller eruption, right? Wrong.
The ash plume rapidly reached FL 400. The upper part of the plume entered the jet stream, which transported the ash cloud as far as the Black Sea and Turkey in a few days. In the last stage of the eruption, the ash cloud covered large parts of the European Region airspace.
In 2004, then, a major eruption that covered a large part of Europe with ash resulted in relatively minor disruption. Why then is the situation different today, six years later, when a similar eruption has caused most of Europe’s airspace to be put out of action?
A clue to the answer may lie in the conclusion of those same meeting notes from 2005:
Although an effective early warning system is in place, the EUR Region lacks an effective and robust contingency plan that would take account of safety of flight as well as the economic penalties associated with airspace closure.
Accordingly, the EUR/NAT Office of ICAO established a Task Force to develop an ATM contingency plan. The Task Force is composed of Iceland, Italy, Norway, Russian Federation, Eurocontrol, IATA and VAACs. The contingency plan, which should take due account of the economic fall out of a major volcanic eruption, would address short term and long term actions to be taken. The contingency plan should be delivered to the European Air Navigation Planning Group at their next meeting in November 2005.
That contingency plan was subsequently developed, and put into effect. (Unsurprisingly, the economic effects are not mentioned in the plan.) The first edition was issued in December 2005 You can download it here.
It was updated with a 2nd Edition in September 2009.
Thus the contingency plan that allowed the shutdown of the whole of European airspace was issued just four years ago. Right up until then, it appears that the plans did not exist to simply shut down the whole of Europe as has been done over the last few days. And yet we got by somehow. Even without that contingency plan, air transport was among the safest ways of travelling.
I would have thought the answer was obvious – Health & Safety – people hell bent on destroying life as we know it.