Dear all, the closure of the air space is a financial hell for the aviation industry. But on the other side I am shocked about the comments of some "professionals" here, who want to fly immediately.
First, the engines are one problem. Damage is highly possible, a complete loss is a much lower risk, but cannot be ruled out.
Second, we have a lot of other dangers, from air data system to give wrong indications up to the damage on the aircraft paint and others. Remember the Potomac Disaster, created by three problems (wrong cockpit indications giving less thrust, a contaminated wing and a pilot having no training and no idea).
The same is here. Too many factors are unknown that we cannot risk to send a full packed aircraft up. And aircraft will be always on the MTOW to get the chaos ended as quick as possible. If KLM makes a test flight with a nearly empty aircraft is one thing, but a full packed 777 on the MTOW going maybe two hours through the cloud stream is a different story.
The major problem is the uncertain, as we have not enough data. And the closure is therefore the only logical consequence, as hard as it is.