After the FAA grounded more than 171 Boeing 737 Max 9s like the one involved in the fuselage blowout over Oregon, United Airlines reported finding loose bolts in some of its aircraft with exit door plugs, Politico reports. Inspections found loose fasteners “that appear to relate to installation issues in the door plug” and “needed additional tightening,” which is not what you want to read as you’re flying 35,000 feet above the ground.