Updated

The union for pilots at Northwest Airlines approved an agreement on Saturday aimed at stopping the end-of-the-month cancellations that have riled the airline's passengers.

The agreement will pay pilots time-and-a-half for flying over 80 hours in a month. Their old cap of 80 hours per month was raised to 90 hours under concessions the airline won in bankruptcy court.

Flight hours refer only to the time between when the plane pushes back from the gate to when it arrives at the gate at its destination, so pilots can spend as much as twice that much time on tasks associated with the flight that do not count as flight hours.

Northwest canceled hundreds of flights at the ends of June and July because it could not find enough pilots. The airline had said more pilots than usual were not showing up for work. Pilots said a new, tougher schedule implemented under bankruptcy is pushing them too hard.

Northwest also said it would pay union workers a bonus of up to 15 percent of their pay — up to $1,000 — if they have perfect attendance between Aug. 4 and Sept. 3.

Northwest said the cost of the extra pay will be offset by the value of other work rule changes and grievance settlements. Before and during Northwest's bankruptcy reorganization that began in September 2005, it set concession amounts for each of its unions and never moved from them. Northwest emerged from bankruptcy on May 31.

Northwest said it would keep working with its unions "to explore cost-neutral ways to improve employees' work environment."