SEATTLE, United States — Pilots for the Air Transport Services Group Inc. unit that hauls packages for Amazon.com Inc. and DHL Worldwide Express were ordered back to work by a federal judge, halting a strike that threatened to disrupt holiday deliveries.

US District Judge Timothy Black in Cincinnati gave a nod to the holiday shopping rush in granting ABX Air’s request for a temporary restraining order for pilots to return to the cockpit.

“The public expects that purchases and shipments will be delivered in a timely fashion,” Black said in Wednesday’s ruling. “Absent an injunction, ABX, its customers and the public will suffer immediate, irreparable harm. Imagine Christmas without Amazon!”

The strike began Tuesday morning and forced the cancellation of dozens of flights. Julie Ford, a lawyer for the pilots union, said the union has withdrawn picket lines to comply with the order, which is effective for five days under federal law.

“The union is obviously disappointed,” Ford said in a phone interview. The pilots will make a decision on how to proceed next week, she said.

The ruling clears a major obstacle for Amazon heading into its first holiday shopping season since contracting with ATSG and another carrier to operate a fleet of cargo planes to shuttle inventory around the country. Those contracts reduced the company’s reliance on FedEx Corp. and United Parcel Service Inc.

Cyber Monday

The pilots are returning to work in time for the online shopping peak between Thanksgiving and the following Monday. Online spending in the US on Thanksgiving, Black Friday and Cyber Monday is expected to reach $8.4 billion, or 9.2 percent of all online spending in November and December, according to Adobe Systems Inc.

ABX Air spokesman Paul Cunningham and Amazon declined to immediately comment on the order. DHL didn’t immediately respond to messages seeking comment on it.

About 250 ABX Air pilots walked off the job to protest the cargo carrier’s alleged staffing shortages. ABX Air operates 35 flights a day for Amazon and 45 for DHL, according to the Airline Professionals Association, Teamsters Local 1224, which represents the pilots. ABX said in its complaint that 26 flights, loaded with 1.25 million pounds of cargo, were grounded Tuesday. By Wednesday, 75 DHL flights had been grounded, the pilots union said.

In issuing his order, the judge said the dispute qualifies as minor because it involves only the interpretation of an existing union contract. That means that it must be submitted to binding arbitration, rather than be brought to a federal court, Black said.

“ABX and the other airlines that service DHL and Amazon are facing a staffing crisis, in large part because they cannot attract and retain talented pilots with the sub-standard pay and benefits they provide,” Dan Wells, president of Teamsters Local 1224, said in a statement. “Pilots should not have to go on strike to get back provisions of a contract that was taken away from them just to ensure they have adequate rest and time with their families.”

The case is ABX Air Inc. v. International Brotherhood of Teamsters, Airline Division, 16-cv-01096, U.S. District Court, Southern District of Ohio (Cincinnati).

By Chris Dolmetsch and Spencer Soper, with assistance from Mary Schlangenstein; editors: Jillian Ward, David Glovin,Michael Hytha and Alistair Barr.