Dutch carrier KLM has thrown doubt on the risk to aircraft from European volcanic ash after finding no technical problems during a test flight conducted with a Boeing 737-800.
The airline expects to receive final results today from an inspection of the aircraft.
KLM conducted the flight in Dutch airspace, from 19:45 to 21:00 yesterday, after securing Dutch Government permission.
"No problems were encountered during the flight," says the airline. The 737 climbed to an altitude of 41,000ft during the test.
Core European airspace has been largely closed since 15 April following the eruption of the Eyjafjallajokull volcano in southwest Iceland and the dispersion of ash towards the European mainland.
"At first glance there is no reason to suspect that anything is amiss," says KLM chief Peter Hartman, who participated in the flight as an observer along with operations head Ype de Haan.
Initial technical checks in a hangar after the landing have also revealed no problems, although KLM says it will obtain final results today.
If these results confirm its expectations, the airline plans to return seven of its aircraft from Dusseldorf to Amsterdam Schiphol.
KLM is awaiting a Dutch transport ministry verdict on whether flight operations can be restored.
The carrier's test flight is likely to stir controversy over the extent of the risk to aircraft and the decision to shut airspace over the northern two-thirds of the European continent.
"We hope to receive permission as soon as possibleto start up our operation and to transport our passengers to their destinations," says Hartman.
KLM was the operator of a Boeing 747-400 which suffered multiple engine failure after encountering an ash plume from Alaska's Mount Redoubt volcano during a service to Tokyo in 1989.