What Passengers Need to Know After the Boeing 737 Max 9 Incident

After an Alaska Airlines Boeing 737 Max 9 jetliner’s fuselage tore off midair on Friday and caused an emergency landing in Portland, Ore., the Federal Aviation Administration ordered the temporary grounding of some Max 9 planes until they are thoroughly inspected.

Hundreds of flights operated by Alaska Airlines and United Airlines were delayed or canceled on Saturday. It’s unclear how the grounding and ongoing inspections will impact flights in the coming days as these and other airlines grapple with concerns over a workhorse aircraft.

The Max, which comes in four variants, numbered seven through 10, is the most popular plane in Boeing’s history, accounting for a fifth of all orders placed since 1955, company data shows.

Here’s what passengers should know about the Max 9 airplane, how airlines are responding to the grounding, and how to navigate any upcoming flight delays or cancellations.

Which airlines fly the Max 9 aircraft?

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

Other operators relying on the Max 9 include Panama’s Copa Airlines, Aeromexico, Turkish Airlines, FlyDubai and Iceland Air.

The F.A.A. grounding of the Max 9 airplanes affects 171 planes operated by Alaska, United, and other airlines.

Each Max 9 can transport as many as 220 passengers, depending on seating configuration.

Are airlines continuing to fly the Max 9?

As of Saturday night, United said in a statement it had “temporarily suspended service” on select Max 9 airplanes to conduct immediate inspections required by the F.A.A. United also said that 33 of it 79 Max 9 aircraft had already received the necessary inspection.

Alaska said in a statement on Saturday afternoon that it had begun inspections early Saturday morning and had cleared 18 aircraft to return to service. The remaining inspections will completed in the next few days, the airline said.

How will the emergency affect passenger travel in the coming days?

As of Saturday evening, Alaska Airlines canceled about 141 flights, or 18 percent of those scheduled for the day, according to FlightAware, a flight tracking service. United Airlines canceled 66 flights, about 2 percent of its daily schedule. Hundreds of flights operated on Saturday by both carriers were delayed.

It is unclear how the aircraft grounding will affect flight schedules in the coming days. Both United and Alaska said they were working with affected passengers to offer alternative travel options.

I’m flying in the coming days. How do I see if I am booked on a Boeing 737 Max 9?

Travelers can typically find information about their plane type when they book their flights online, either during the seat-selection process or elsewhere on the airline’s website.

Passengers may also be able to find the aircraft type in an airline’s mobile app. For Alaska, this is available in the app’s “Details” section. Flight tracking websites, such as FlightAware, also have plane information if users search for specific flights using the flight number.

However, even if passengers know in advance what plane they are scheduled to fly on, this is always subject to change. Airlines swap out aircraft at the last minute, depending on factors such as weather and logistics.

What can passengers do if they are affected by a cancellation? Can they change itineraries?

Alaska has issued a “systemwide flexible travel policy” allowing passengers to cancel or change their flights without incurring any fees, because of the Max 9 inspections and a forecast of wintry weather in the Northeast. The airline is encouraging travelers to use the Alaska website or app themselves, rather than calling the airline’s customer service line (waits are long).

For those with upcoming flights, Alaska is directing passengers to check their flight status online. If your flight was canceled, you can get a refund or future travel credit.

United flight status updates can be found online. If a flight incurs significant delays, United will waive change fees or grant a travel credit or refund. The airline has not issued a specific waiver related to the aircraft inspections that would further relax policies.

And if your flight is delayed or canceled, you may be entitled to compensation, depending on the circumstances.

What is the history of Boeing Max planes?

Boeing Max aircraft have been dogged by catastrophe in recent years. Within a span of several months in 2018 and 2019, two Boeing Max 8 airplanes crashed, killing hundreds of passengers and crew. All Max aircraft were then grounded around the world, for nearly two years, while company engineers worked to identify the problem.

With additional reporting by Callie Holtermann and Niraj Chokshi.

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