Airlines have begun inspecting 312 of Boeing Co.'s 737 family of aircraft, including some of the grounded 737 Max, because they have wing components that are prone to cracking. The parts must be replaced within 10 days, U.S. regulators said.

Boeing informed the Federal Aviation Administration that so-called leading-edge slat tracks may not have been properly manufactured and pose a safety risk, the agency said in an emailed statement Sunday. The parts allow the wing to expand to create more lift during takeoff and landing. U.S. carriers reported few aircraft covered by the warning Monday and said flight schedules wouldn't be affected.

While less critical than the global grounding of its 737 Max since March, Boeing's latest production issue adds another headache for a management team trying control the fallout from two deadly crashes and get the U.S. manufacturer's top-selling plane flying again. The head of the International Air Transport Association warned airline CEOs at the industry's annual gathering this past weekend that the plane-approval process is damaged and the industry is under scrutiny.