Shares of Boeing Co. dropped around 1% on Thursday after the aerospace and defense company urged airlines and other operators to check for possible loose bolts on its 737 Max jets. The fresh issue with the family of single-aisle jets may affect the planes’ rudder-control system, the Federal Aviation Administration said Thursday. The FAA is “closely monitoring” the inspections in conjunction with Boeing BA, -1.15%, it said. Boeing has warned operators to inspect “specific tie rods that control rudder movemen ...