After a portion of an Alaska Airlines Boeing 737 Max 9 jetliner’s fuselage blew out in midair minutes after taking off from Portland, Ore., on Jan. 5, the Federal Aviation Administration grounded about 170 Max 9 planes, causing airlines that rely heavily on the aircraft to cancel thousands of flights and inconveniencing many passengers.

On Wednesday, the F.A.A. approved inspection and maintenance procedures for the planes, clearing the way for the grounded Max 9 planes to fly again.

Airlines said they planned to resume flying the Max 9s this week. Here’s what passengers should know about the plane and their rights if they want to avoid flying on it.

Which airlines use the Max 9?

Of the 215 Boeing Max 9 airplanes flown globally, United Airlines operates 79, the most of any airline, and Alaska has 65, according to Cirium, an aviation data provider. Their combined fleets represent about 70 percent of the Max 9 jets in service.