Frankfurt Airport (FRA) operator Fraport confirmed that apron control workers, represented by the German union GdF, will extend their strike to Friday from 8 a.m. to 10 p.m. local time (ATW Daily News, Feb.16). The strike could causes cancellations and delays of more than 1,000 flights.

The GdF union, which represents about 200 runway workers, asked members to walk off the job for seven hours Thursday.

The move comes after the union failed to reach a wage agreement for the workers with airport operator Fraport.

Fraport has trained additional staff to replace striking workers and hopes that at least half of FRA’s scheduled flights will take place during the walkout.