Delays and cancellations were expected at several German airports on Monday as security workers at passenger control checkpoints hold an all-day strike over pay and conditions. At Cologne/Bonn Airport, the employees stopped work “completely” shortly after midnight, the Verdi union confirmed to dpa. Strike action is also planned at airports in Düsseldorf, Berlin, Bremen, Hanover and Leipzig. The operator of Berlin-Brandenburg Airport said passengers should contact the airlines about potential delays or cancellations and plan more time for their journey. Airport operators in Düsseldorf and Colog…