German airport Deutsche Lufthansa AG was forced to cancel 67% of its flights today after pilots walked off the job. The strike, by a Unite union representing some 12,000 pilots, began this morning and is scheduled to last until Thursday. The airport management has filed suit in a Frankfurt court calling the strike 'disproportionate,' but also rejected a union proposal yesterday suggesting that a return to arbitration be scheduled if management would agree to apply pay scales equally to all employees. The suit contends that some sectors of pilots have violated no-strike clauses in their labor contracts, and says that at least some of the pilots should not be allowed to strike. Trouble is also brewing for British Airways, as the airport awaits the results of a cabin crew strike vote, that could authorize a work stoppage as soon as March 1. Strikes at both airlines are expected to be expensive - perhaps costing up to 25 million pounds/euros per day.