(New: Details)

FRANKFURT (dpa-AFX) - Bose surprise at Frankfurt Airport: after just a few hours of operation, the newly renovated northwest runway had to be closed again. Shortly after the opening on Wednesday, Lufthansa had complained, which had noticed massive tire abrasion on its aircraft after landing. Some of the rubber tyres were even no longer serviceable, so that no more landings would be made there for safety reasons.

In the past two weeks, the 2800-meter-long concrete runway had first been cleaned of rubber abrasion and, for the first time in Frankfurt, provided with a special anti-slip surface. According to the manufacturer "Possehl Spezialbau" from Rhineland-Palatinate, the surface "Fl8Safe" made of epoxy resin and grit is said to be significantly more grippy and durable than conventional asphalt. Even in extreme weather, the surface still appears dry due to the effective drainage and enables aircraft to land safely with short braking distances.

The area of unavoidable rubber abrasion during landing is also said to be reduced by around 40 percent with "Fl8safe". During checks after landing, Lufthansa apparently found the opposite to be true. "There is massive tire abrasion on landing and an accumulation of tires that are no longer usable after landing," according to an internal memo quoted by the portal "Aero.de." Possehl did not initially comment in response to an inquiry.

Airport operator Fraport reacted immediately on Thursday and closed the runway until further notice. After an investigation, Fraport sent rollers to the "Northwest" to smooth the pavement. "This will ultimately be used to simulate landings," a company spokesman explained. It was not possible to predict how quickly the runway would be back on the grid.

Although the surface was applied for the first time in Frankfurt, it has been tried and tested at other airports in Europe, explained a Fraport spokesman. The runway specifications of the civil aviation organization ICAO are all complied with. The Vereinigung Cockpit pilots' union was generally positive about "anti-skid pavements", which make landings much safer. You can feel the delay very clearly, said pilot and VC spokesman Matthias Baier.

The northwest runway - opened only in 2011 by then-Chancellor Angela Merkel (CDU) - is actually urgently needed for upcoming summer travel, which is expected to return to pre-Corona levels on some days. Germany's largest airport does have two more runways and one runway exclusively for takeoffs. But this runway, "18 West," must be closed for safety reasons in the event of stronger northerly winds, threatening severe bottlenecks. According to Fraport, operations were running smoothly on Thursday.

During the two-week runway rehabilitation, the upper limit of aircraft movements in the airport system was capped from 94 to 84 per hour. German Air Traffic Control in Langen continues to expect significant delays if the northwest runway remains closed. Already in the past two weeks, there have been significant delays of up to 30,000 minutes a day at Frankfurt Airport during construction work, it said. Around 120 flights had been cancelled altogether during this period. Fraport already asked passengers to inform themselves about the respective status of their flights./ceb/DP/ngu