Northwest Airlines and the union representing its pilots have reached a tentative deal that may prevent spikes in the airline's flight cancellations like those seen in late June and late July, the airline said on Wednesday.

The airline said it obtained contractual changes on several work rules pertaining to international flying, and the settlement of outstanding grievances. In exchange, Northwest agreed to reinstate premium pay of 50 percent for all pilots for any flying over 80 hours, effective August 1.

The agreement is subject to ratification by the Northwest Air Line Pilots Association Master Executive Council.

Northwest also said it has proposed a Summer Reliability Incentive Program under which all contract employees, including pilots, will receive incentive pay equal to 15 percent of eligible earnings up to USD$1,000 if they achieve perfect attendance between August 4 and September 3.

That proposal also is subject to ratification by the pilots' union.

A Northwest spokesman said on Monday the carrier completed about 92 percent of its scheduled flights from July 27-29 compared with the rate of about 99 percent that is more typical for the airline. A surge in cancellations cost Northwest USD$25 million in lost revenue in the second quarter.

Northwest suffered the extraordinarily high cancellation rates at the end of the last two months, blaming the problem on "pilot absenteeism." The airline has not given a reason for the absences.

The Air Line Pilots Association, however, said absenteeism is not the problem. Rather, it said, the cancellations result from the airline having too few pilots to work the busy summer flying schedule.

Work rules the pilots agreed to during the carrier's 20-month bankruptcy, which ended in May, often require pilots to spend more time in the air.

Government rules permit pilots to fly longer hours, but Northwest's system has exhausted the workers, who routinely fly up to 90 hours a month, said ALPA spokesman Monty Montgomery.

Furthermore, the workers were not paid at a higher rate for working more than their required hours. The previous contract offered that incentive.

As a result, the pilots simply are not volunteering to work beyond the number of hours they are required to fly, he said.

Northwest and ALPA agreed to the new contract as part of the carrier's effort to cut is labor costs by USD$1.4 billion a year.