Business aircraft grounded by ash from an Icelandic volcano were back flying in Europe's skies minutes after authorities lifted widespread airspace closures Tuesday night. Charter operators and brokers have reported an exceptional flurry of bookings as displaced passengers try to beat the airline backlogs to get home. Aviation authorities reopened European airspace with the caveat that operators must perform their own risk assessment for any given operation before filing a flight plan. While operators enjoyed nearly unimpeded flying conditions over the last two days, authorities warned that for as long as Iceland’s Eyjafjallajökull volcano is active, airspace could still be subject to partial closures and restrictions. The latest meteorological maps showing current and projected ash concentrations can be found at the UK Met Office website. Aircraft operators should also confer with engine manufacturers on maintenance issues relating to possible exposure to varying levels of volcanic ash. Some have expressed concern that warranties might be invalidated by flying in these conditions and there have also been questions as to whether insurance policies might cover flights. Maintenance cost-per-hour program provider JSSI confirmed that damage to engines caused by “foreign materials,” including volcanic ash, is not covered by its support policies.