United Airlines has found loose bolts and other “installation issues” on multiple 737 Max 9 aircraft, it said on Monday, referring to the Boeing model that has been grounded after a panel blew off an Alaska Airlines-operated plane mid-flight over the weekend.The industry publication Air Current reported that United found discrepant bolts on other parts on at least five panels that were being inspected following the accident. The US Federal Aviation Administration (FAA) and Boeing declined to com...