An airline crash not only means the almost certain death of hundreds of passengers, but it can also have devastating consequences on the ground in terms of further casualties.
So there can be no question that the initial decision made by the European authorities to suspend flying over much of the continent in the immediate aftermath of the eruption of the volcano in Iceland was the right one.
By last night, however, there were indications that the dangers of jet planes flying through the cloud of dust appeared to have been overestimated, with several airlines – including British Airways – taking to the skies for what appeared to be successful test flights.
Defending his organisation's stance, Brian Flynn, deputy head of operations at Eurocontrol, the European Organisation for the Safety of Air Navigation, said he could understand the frustration of airlines, and that the results of test flights were being analysed.
Because of the consequences of getting the decision wrong, these matters should not be rushed, but nor should there be an undue delay as the effect that the widespread cancellation of flights across Europe is beginning to have a significant impact on the country's economy.