How will the problem with the Boeing 737 Max 9 affect air traffic?

As shocking as the crash on Alaska Airlines Flight 1282 last week was, federal officials initially estimated that the problem that left a gaping hole in the plane's fuselage would be relatively easy to diagnose and fix. are.

However, on Tuesday the Federal Aviation Administration said the process will take a little longer than expected. For now, all aircraft configured similarly to Flight 1282 – a recently introduced update to the wildly popular Boeing 737 – remain grounded.

That means more travelers on United and Alaska airlines will cancel their flights in the coming days. Here's what we know so far about the disruption to air travel, when it could end, and what the eventual return of these planes to service could mean for flyers – especially the nervous ones.

Which aircraft are affected?

Flight 1282 was on a modified version of the Boeing 737 Max 9, the latest in a series of revisions intended to enlarge the 737s so they could carry more passengers and generate more revenue. The Max 9s are almost 8 feet longer than the 737 Max 8s that came out a few years earlier, and if they can carry the full complement of seats, they will need an additional emergency exit between the wings and the tail.

The number of emergency exits needed depends on the number of seats, said Robert L. Ditchey, an aviation consultant based in Marina del Rey. But a few airlines ordered a modified version of the Max 9 with fewer seats, eliminating the need for additional exits. That means fewer potential tickets sold, but also fewer maintenance costs associated with the emergency door and exit slide, he said.

Instead of making a new fuselage for the alternate version, Boeing used the same one, but plugged the holes for the two additional emergency exits with a plate bolted to the frame. That's the part – known as the door plug – that blew off on Flight 1282 when the plane's interior was pressurized.

Which airlines have the planes grounded?

Boeing would not reveal its customer list, but Alaska and United Airlines are the only domestic airlines publicly identified as having the modified 737 Max 9s. United says it has 79 Max 9s, and Alaska says it has 65.

The aviation website flight radar24 named three foreign airlines operating Max 9s with door plugs: Copa Airlines, Aeromexico and Turkish Airlines.

The FAA, whose jurisdiction extends only to U.S. airlines, says it has ordered the grounding of 171 planes. That represents a small percentage of all aircraft in service in the United States. Still, neither Alaska nor United have enough planes to operate all the flights scheduled to be handled by their Max 9s, causing more than 200 cancellations every day.

United said Tuesday it was canceling 170 flights and redeploying other planes to replace Max 9s on 45 others. Alaska said it had canceled 109 flights as of 12:30 a.m. Tuesday.

How long will the planes remain on the ground?

Nothing is certain at this point, but Alaska Airlines said Wednesday it was canceling all flights on 737 Max 9s until Saturday January 13th.

The FAAs emergency airworthiness directive establish a process by which the affected aircraft can be returned to service. The aircraft would be inspected by the airlines according to FAA guidelines, and they would take whatever corrective action was necessary. The inspections would take only four to eight hours by plane, the agency estimated Saturday.

This is standard procedure for the FAA, which does not have the staff to conduct inspections itself, Ditchey said. Instead, it leaves the job to certified technicians who work for the airlines.

The delay here is reaching the point where inspections can begin.

On Tuesday, the FAA said on X.com (formerly Twitter) to begin the process of Boeing issuing instructions to the airlines on how to inspect and maintain the plugs. “Boeing provided an initial version of the instructions yesterday, which they are now revising based on feedback received,” the agency said. “Upon receipt of the revised version of Boeing's instructions, the FAA will conduct a thorough review.”

“The safety of the flying public, and not speed, will determine the timeline for returning the Boeing 737-9 Max to service,” the FAA said.

Industry analyst Bob Mann said the revised instructions likely address what the airlines discovered when they began examining the plugs in preparation for the inspections. “Most of the maintenance is like this: You go in there looking for one thing and you find three things,” he said.

How long the work will take depends on what kinds of problems are uncovered, Mann said. For example, it may be a matter of tightening the existing fasteners better, or a different type of fastener may be needed.

Still, analysts predicted the planes would be back in service within two weeks. “Nothing I've heard yet is at the level of, 'We want to redesign this,'” Mann said.

How do I know if this will affect the flight I booked?

The short answer is that you don't know for sure because the airlines can put new planes on routes after you buy your ticket. But if you go to the airline's website, you can see which type of aircraft is now assigned to your route. One thing to keep in mind is that the plane on the ground is a 737 Max 9, not a 737-900. The names are similar, but the latter is an older aircraft that was part of an earlier series of updates from Boeing.

What should I do if my flight is cancelled?

With some restrictions, Alaska is allowing passengers rebook their flights for free, and in some cases to cancel their flights for future credit. United is also allowing free rebookings for passengers on affected flights full refunds.

Paul Hudson, founder of the airline passenger advocacy group flyersrights.org, said passengers on canceled flights are entitled to a refund. “You are absolutely entitled to a refund of your ticket. You do not have to accept a voucher or a later flight,” said Hudson.

Granted, a refund for a ticket purchased well in advance likely won't cover the cost of a flight booked at the last minute. And airlines are not required to offer you an alternate flight on the same day, or to offer you a hotel room, if you are forced to stay away from home overnight during your trip within the U.S., Hudson said. These types of accommodations are subject to each airline's policy.

Hudson said that with the number of flights being canceled even when planes are not on the ground, travelers should always have a backup plan. One way to do that, he said, is to have a second, fully refundable ticket on another airline to get you to your destination in case the first flight you reserved is canceled.

Other suggestions are to build in an extra day of travel, book nonstop flights to avoid being stranded halfway to your destination, and to book flights that depart in the morning, Hudson said. “Because if your flight is canceled or delayed, you have time to make other arrangements,” he said.

Should I be concerned about flying Max 9s in the future?

The Max series hasn't exactly enjoyed a honeymoon. After the Max 8 planes were introduced, problems with an automated flight control system caused two planes to crash in Indonesia and Ethiopia, killing 346 people and prompting regulators around the world to ground the planes for at least 20 months to hold. These aircraft have been back in service in the US for approximately four years. “Once [the Max 8] was back, it did exactly what it was supposed to do,” Mann said. The same flight control system is in the rest of the Max models.

Ditchey argued that the problem with the Max 9s requires a structural change, not just stronger fasteners. This is due to the stress caused by the difference in air pressure inside and outside an aircraft.

Airlines pressurize their interiors as they climb because there isn't enough oxygen to support life in the thinner atmosphere at higher altitudes. But if a hole in the fuselage suddenly opens when a plane is high above the Earth, the higher pressure inside could cause people and objects to be ejected from the plane.

(On that note, it was a good thing that Flight 1282 had an explosion shortly after takeoff, then 16,000 feet instead of 30,000, and that there was no one in the seat next to the plug. “If you have a big gap and someone is sitting next to that gap and he or she isn't wearing a seat belt… color them out,” says Barry Schiff, an aviation safety consultant.)

Ditchey said emergency doors, like regular aircraft doors, are larger than the opening in the fuselage they fit into, causing them to be more tightly bound to the frame by internal pressure. However, the plug does not have such a 'failsafe'. A real solution, he said, would require designing the plug with a failsafe like the emergency doors.

Mann disagreed, saying that if the plug is properly secured, it should adequately transfer the stress of pressurization to the hull.

Hudson said that after the Max 8s returned to service, the airlines offered penalty-free flight changes to any passenger who did not want to fly on one of those planes. “That's all gone now,” he said.

Whether airlines will take a similar approach with the Max 9s, he said, “depends on public pressure.”