July 5, 2022: -A malfunction in a scheduling platform let American Airlines pilots decline thousands of July assignments in one day, their union said, a headache for the airline as it attempts to underestimate flight disruptions in a successful travel season.

American said it didn’t expect the problem to affect its function during the busy July 4 holiday weekend. The union and airline are discussing additional pay for pilots whose declining trips the airline reinstated, the Allied Pilots Association said.

“As a result of this technical glitch, certain trip trading transactions were able to be processed when it shouldn’t have been permitted,” the airline said in a statement. “We already have restored the vast majority of the affected trips and do not anticipate any operational impact because of this issue.”

Over 12,000 July flights did not have either a captain, first officer, or both after pilots dropped assignments, the Allied Pilots Association said Saturday. APA said the airline reinstated about 80% of the trips.

Pilots can routinely drop or pick up trips, but time off in the summer or holidays is hard for airline employees as schedules peak to cater to strong demand.

On Saturday alone, American had more than 3,000 mainline flights scheduled, and they were 93% full, according to an internal tally. Flights left unstaffed, however, are an additional strain on any airline.

The glitch occurred during a rocky start to the Fourth of July weekend when thunderstorms and staffing issues caused thousands of U.S. flight delays and hundreds of cancellations.

A similar issue occurred in 2017 when a technology problem let American pilots take a vacation during the busy December holiday period. The carrier offered pilots 150% pay for pilots that picked up assignments.

American and its pilots’ union, whose relationship has been fraught, are in the middle of contract negotiations and the airline most recently offered nearly 17% raises through 2024.

Union president Capt. Ed Sicher, who began his term on Friday, told American’s almost 15,000 pilots Saturday night that American Airlines CEO Robert Isom said he is committed to paying an “inconvenience premium” to pilots whose trips Americans put back on their schedules after the inconvenience.

“To Mr. Isom’s credit, he contacted me four times today to commit to mitigating the damage from this debacle,” Sicher wrote on Saturday. “We started at a 200% override, although the details of this pay are still the subject of negotiations, and there is no proof of the details or the amounts.”