The European Commission publishes since March 2006 a blacklist of so called unsafe airlines at intervals of at least three months.

Which carriers are included in this list? Especially those that are unable to meet international safety standards – as for example airlines that operate with poorly-maintained or outdated aircraft. Those airlines are not allowed to carry passengers or cargo within the EU and are generally not permitted to operate within European airspace.
If a carrier is banned in one of the EU member states this ban also applies to all other EU members, Switzerland and Norway.

You can find the current blacklist here.