United Airlines, which has 79 Boeing 737 MAX 9 aircraft, did not confirm how many planes had loose bolts.
United Airlines found loose bolts on the door plugs on several of its grounded 737 Max 9 planes days after a door plug of an Alaska Airlines plane while it was in-flight.
„Since we began preliminary inspections on Saturday, we have found instances that appear to relate to installation issues in the door plug – for example, bolts that needed additional tightening,“ United said in a statement to CBS News.