A pilot strike is threatening to ground flights carrying cargo for Amazon during the busy holiday season.
About 250 pilots employed by ABX Air, a subsidiary of Air Transport Services Group Inc., went on strike Tuesday morning to protest alleged staffing shortages.
Now Amazon and shipping company DHL Worldwide Express, which are both customers of ABX, will have to pay the price.
ABX operates 35 flights daily for Amazon and 45 flights a day for DHL, according to Teamsters Local 1224, the union representing the pilots.
This could cause major disruptions and delays for some Amazon customers during the busy holiday season, according to the union. Amazon did not immediately respond to a request for comment.
ABX Air President John Starkovich said the company is "notifying its customers and other affected parties about temporary interruptions in ABX's flight operations, allowing them to adjust their networks until pilots return to work and normal flight operations resume."
"We stand ready to assist our customers in any way we can to minimize any impact on their own operations during this critical holiday period," he said in a statement to Business Insider.
The company is also seeking a court order to force pilots to return to work.
"We expect the court will uphold our position that the actions taken by the union to refuse work assignments is not legal, and the issues involved constitute a minor dispute to be resolved via arbitration under terms of our current labor agreements," he said.
The pilots say they are striking because they have been forced to work "emergency assignments" during contractually obligated time off as a result of alleged understaffing.
So far this year, pilots have been scheduled to cover more than 8,000 emergency assignment days on days they should have had off, according to the union.
The striking pilots are picketing on Tuesday outside of ABX Air's headquarters in Wilmington, North Carolina and outside DHL's North American hub at Cincinnati/Northern Kentucky International Airport.
Pilots at ABX Air and four other cargo carriers that fly for DHL voted to strike earlier this year if negotiations with the company stalled.