Boeing shares tumble Boeing shares plunged 8% on Monday after the Federal Aviation Administration ordered airlines to ground dozens of Boeing 737 Max 9 aircraft for urgent inspections. The order was issued on Saturday after a door plug blew out in the middle of an Alaska Airlines flight on Friday. The bad news kept piling on, as United Airlines said that it found loose bolts on door plugs of several Boeing 737 Max 9 planes. Markets get a tech boost Wall Street's main indexes kicked off the week with gains, boosted by tech shares.