German authorities extended the closure of the country’s airspace by six hours to 1800 GMT Tuesday due to the giant plume of volcanic ash, but some airlines operated flights with special permission.
Germany’s DFS air safety agency said 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.
DFS said that up to 800 flights would be granted permission to fly visually rather than relying on instruments by staying in constant contact with air traffic controllers.
“That is equal to about seven percent of the normal air traffic,” DFS spokesman Axel Raab told rolling news channel N24. “Because the aircraft will be flying according to the rules of visual flying, we can only permit a limited number to take off.”
German flag carrier Lufthansa had said earlier 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.
And Air Berlin, Germany’s number two, had said earlier that it 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.
But both airlines made the announcements before the extension of the flight ban.
On Monday, Lufthansa, which along with other European carriers criticised the shutdown, managed to carry around 15,000 people. Normally the airline operates some 1,800 flights daily.
Lufthansa announced a fresh test flight with an Airbus A340-600 from the western city of Frankfurt later Tuesday that will test the air quality beyond Germany’s borders over the course of several hours.
Scientists from the German Aerospace Centre carried out a preliminary 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 Bayerischer Rundfunk radio.
“There really is a cloud,” spokesman Andreas Schuetz said.
Further results from the test were due later 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.