German airspace closed until 1800 GMT Tuesday: authorities
German authorities extended the closure of its airspace by six hours to 1800 GMT Tuesday due to the giant plume of volcanic ash, but some airlines operated flights with special permission.
A spokeswoman for Germany's DFS air safety agency said that the flight ban was still in effect but that authorities were granting exceptions for some flights at lower altitudes.
Late Monday, the DFS had extended the no-fly period to 1200 GMT Tuesday due to the volcanic ash from Iceland in the atmosphere that has caused havoc for millions of European air passengers since last week.
Meanwhile German flag carrier Lufthansa said it planned to carry more than 15,000 passengers on some 200 flights on Tuesday, representing just over 11 percent of its normal daily schedule.
Lufthansa, Europe's biggest airline by passenger numbers, would make use of special permission to fly visually rather than relying on instruments, and stay in constant contact with air traffic controllers, a spokesman told AFP.
"Today (Tuesday) all long-haul flights with only a few exceptions as well as some intra-European and domestic flights will take place," Lufthansa said in a statement.
"During the day Lufthansa plans to expand its flight plan gradually," it added, saying that whether a flight would operate "depends on the current conditions."
It published on www.lufthansa.com a list of which flights were operating.
On Monday, the airline, which along with other European carriers criticised the shutdown, managed to carry around 15,000 people. Normally Lufthansa operates some 1,800 flights daily.
Air Berlin, Germany's number two, was confident it would have "almost a complete programme" Tuesday, with "significantly" more than the 104 flights operated on Monday, which carried 15,000 passengers, a spokeswoman told AFP.
Scientists from the German Aerospace Centre (DLR) carried out a test flight Monday and were able to see a definite brown tinge in the clouds from the volcanic ash with their bare eyes, a spokesman told Bayerische Rundfunk radio.
"There really is a cloud," spokesman Andreas Schuetz said.
Further results from the test were due later on Tuesday.
The German pilots' union Cockpit expressed concern that allowing planes to fly visually rather than relying on instruments was unsafe before the test results were known.
"Our assessment is that it cannot be safely ruled out that incidents could occur," spokesman Joerg Handwerg said on ARD public television late Monday. "Pilots feel under pressure because they feel obliged by employers to fly."
But Transport Minister Peter Ramsauer defended the decision.
"I am acting in a responsible manner," he said.
© 2010 AFP