About the data matter: not enough data, not interpreting the data correctly, using the data incorrectly, drawing the wrong conclusions from the data, gathering the wrong data and making rules based on any of these miscalculations are all symptoms of a related issue. Data is not a simple matter and over-simplifying data is dangerous. Making mistakes with data is only better that not having data in that when you misuse data you look only slightly smarter than when you didn’t have data at all, but in the end, having the wrong data has the same net result as having “no data” — you make bad decisions.

Whether in deciding how to deal with the volcanic ash in the airspace or dealing with other matters, decisions without data (whether it’s “no” data or the wrong data, etc.) is a bad idea. And, the new rules for dealing with the ash (or in the future) validate the point that they now have much better data, modeling, methods, and decision structures than before. Actually, they didn’t have *any* before — which was really the point of my post. They were making decisions without knowing on what to base their decisions. In other words, they were reacting (which is more reflexive and involuntary) instead of responding (which is more deliberate and measured).

And, just for your information, I happen to be an Aerospace Engineer and a pilot. So, before you open your mouth about what I am or am not qualified to speak on, go get your data.

Thanks for proving my point.

For example, KLM Flight 867 clearly proved that volcanic ash can and does pose an air safety risk. Since it is currently unclear at what density the ash particles become a serious hazard, it’s prudent (or “worst-case thinking”, if you prefer) to err on the side of caution and preservation of human life.

As for the decision making process, let’s stop pretending once and for all that management and decision making is the same across the board, context-free and easily canned. I don’t think knowledge and experience in CMMi, on its own, makes anyone qualified to criticize the way the Eyjafjallajökull volcano eruption was handled. It doesn’t mean you shouldn’t voice your opinion — it’s a free Internet and you do have some interesting points — but it does mean that it should be taken with more than a grain of salt. As Steve Yegge said, “Have you ever legalized marijuana?” steve-yegge.blogspot.com/2009/04/have-you-ever-legalized-marijuana.html

Ash isn’t water.

A quick Google search yielded this: http://cat.inist.fr/?aModele=afficheN&cpsidt=18291511 . They’re discussing a prototype algorithm for detecting volcanic ash with standard weather radar, and the paper is from 2006.

Again, human safety trumps economics. I’m betting that no one on board BA 9 or KLM 867 would argue with Eurocontrol’s decision.

(Also, for what it’s worth, the BA 9 example isn’t an example of “very low ash density”.)

In very low ash density, and in dry air, using RADAR to determine the scope of ash mass is just misguided.
But, we know that Eurocontrol was entirely unguided, so to be misguided about how to interpret weather RADAR isn’t a surprise.

There was a massive high pressure system over Europe and most of the eastern Atlantic on the days before, during, and after the volcano’s ejections of ash and debris. Yes, high pressure is generally dry air, but to be so dry as to render the data useless is something that didn’t seem to come into the picture — if it was even the case that it was so dry, I don’t know, I haven’t looked-up the weather data.

Also, for ash to not even show up on RADAR means the density must have been very low. Ash molecules are not smaller than water molecules, and for the density to be so low that they don’t even appear as water means the impact would have been unnoticeable.

Nonetheless, I’m not arguing that Eurocontrol *should not* have shut down the airspace. I’m sure there were several hours, if not days where there was significant ash all over the region. What I’m arguing is that it was likely shut down far longer than necessary, and, their strategy was mostly to wait and see what the volcano and the weather were going to do to the cloud rather than to work on coming up with standards and measures against them. The airlines and manufacturers took the lead on that.

Sometimes extreme decisions must be made without adequate data in order to maintain public safety. In this case, what would the headlines be saying if Eurocontrol had NOT shut down the airspace totally, and one or more aircraft had crashed? How would the public have reacted?

So, was Eurocontrol overly cautious? Perhaps.

Have airlines cut corners on maintenance to save costs at the expense of safety in the past? Do they command their pilots to fly through known turbulence in order to save on fuel costs? Were they putting immense pressure on Eurocontrol to get back into the air in order to keep revenues flowing? Yup.

Given those data, I believe that despite the disruption to the general public the decision was the most prudent under the circumstances.

Dave Rooney
Westboro Systems