A Boeing passenger jet model, the 737 Max 9, remained grounded in the United States on Sunday as airlines awaited instructions from the plane maker and the Federal Aviation Administration on how to inspect the planes and resume service, two days after a harrowing flight raised concerns about the jet.
No one was seriously injured in the episode on an Alaska Airlines flight on Friday night in which a portion of a Max 9 fuselage blew out in midair, exposing passengers to howling wind. The plane landed safely, but the event, on a flight from Portland, Ore., to Ontario, Calif., has spooked travelers and prompted an immediate call for safety inspections on Max 9 planes with similar seat configurations.
Boeing and the F.A.A. were working to draft a message to airlines — primarily Alaska and United Airlines — with detailed instructions on how to inspect the planes, according to a person familiar with the process. Those discussions were well underway on Sunday, and the F.A.A. has final approval over the contents of the message, as is typically the case.