A potential strike at Boeing’s St. Louis defense plants threatens to derail the U.S. Air Force’s most critical aviation program. Over 3,200 union workers rejected a contract offer, setting the stage for a work stoppage on August 4 that would halt work on the F-47 fighter—the centerpiece of the Next

The number of workers planning to strike is an “order of magnitude less” than the 30,000 machinists who went on strike last fall in the Pacific Northwest, CEO Kelly Ortberg said Tuesday during the company’s second quarter earnings call.

Boeing is facing yet another challenge as 32,000 members of the IAM union are threatening to strike this month if a deal isn't reached on a new contract with the company.