Obviously the number 1 priority is always safety, but can you err too far on the side of safety?

The simple fact is that without data, you have no choice! This is not the case of people making over-safe decisions, it's about a community that was lacking even the most fundamental data to make even partially informed decisions.

Here are some points to hone in on some of those issues:

1) Incentives are not aligned: Airlines are suffering, hemorrhaging cash each day that the airspace remains restricted. The government is, by definition, conservative. Airlines are also conservative when it comes to safety issues, but the accountability vs. cash trade-off is not the same for the two parties. In the absence of established policies, this means a difference of opinion. For example, Lufthansa has strong incentives to test fly one or two specific routes to try and get some planes in the air. The German government, however, might choose to play it safe and keep the airspace closed completely. It's a defendable decision, carries lower risk, and they do not share in the cost.

2) Aircraft / Engine manufacturers who don't know their planes: Who do you think should know the most about the impact of ash on airplane engines? Why, I would think the folks who make them. Most notably GE, SNECMA, Rolls Royce, P&W on the engine side, and Boeing and Airbus on the airframe side. Everyone from Boeing to the first officer knows the plane's limits of operation when it comes to altitude, winds, convection, snow and ice, etc. This enables airlines to fly the planes to their safe limits on a daily basis, meaning the airspace doesn't shut down in mild conditions. But it is abundantly clear nobody really knows the limits of engine in ash clouds? What is the particle density that will shut down an engine? Is it different based on aircraft or engine size? Is it different at different altitudes? Does it depend on time in the ash cloud? Do different ash clouds impact engines differently? I've seen no evidence that anyone knows the answers to these questions in a way that allows us to plan around them.

3) Nobody tracks ash: It turns out it's not so easy to track the size, density, location, and movement of ash clouds. Weather radar isn't effective, and aside from spot checks, it's really hard to tell. Sounds like an epic fail to me. Surely some volcanologist, weather agency, or aviation authority should be tracking this stuff, no? It would enable planes to fly in places where ash readings were lower. It would also allow some predictability rather than repeating "the airspace will open shortly" day after day for a week.

3) Policies exist for a reason: This is a great example of what happens when there are no policies in place. Europe has become far more unified since the EU and EuroControl is one of those great organizations that coordinate airspace among most of the member countries. But EuroControl is a coordinating body, not a governmental body. As such, there is no unified decision making authority. Couple that with the fact that there were no policies in place to deal with ash clouds over the mainland. No contingency plans. No playbook to follow. We have manuals for how to deal with the most arcane events in society -- obviously we can't cover them all, but it would seem that someone would have some idea of what would happen in this scenario.

At the end of the day (as I said last week), mother nature wins. We just tip our cap and hangout another week at Heathrow. But there are graceful and not-so-graceful ways to do that.

Case in point: In 2007, JetBlue has nightmare snowstorm. Nobody gets anywhere, massive number of planes, passengers, and crew stranded. Since then, JetBlue over-compensates by canceling flights in advance. The disruption is awful in either case, but at least they handle it gracefully now because they have a plan.

In today's risk management world, it's amazing nobody had an ash plan. Here's hoping that's corrected soon. After all, last time this volcano erupted, it did so on and off for 2 years! That's a lot of canceled flights.