Boeing 737 Max 9 jetliners will carry passengers in the United States again, starting this weekend, for the first time since they were grounded after a panel blew out of the side of one of the planes.

       Alaska Airlines plans to resume flights with its Max 9s on Friday, and United aims to follow suit on Sunday. Those are the only two U.S. airlines that operate this particular model of the Boeing 737.

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       After seeing video of the frightening flight of a plane with a gaping hole in its side, passengers might reasonably be asking questions about safety.

       The Federal Aviation Administration has detailed the process that airlines must follow to inspect — and if necessary, repair — the panels called door plugs, one of which broke loose on Alaska Airlines flight 1282 on Jan. 5. The plugs are used to seal holes left for extra doors on the Max 9 when an unusually high number of seats requires more exits for safety reasons.