An emergency landing of an Alaska Airlines Boeing 737 Max 9 jet in Portland, Oregon, on Friday prompted the Federal Aviation Administration to order some U.S. airlines to suspend the use of some Max 9 planes pending inspection. The order affects about 171 aircraft operated by Alaska, United and other airlines. The episode also raised troubling new questions about the safety of a work plane that has been plagued by years of problems and several fatal crashes.
No one was seriously injured in Friday's incident. The jetliner returned to Portland airport shortly after part of the plane's body broke off in mid-air, leaving a door-sized hole in the side of the plane.
A few hours after the incident, Alaska Airlines announced that it would ground all 65 Boeing 737 Max 9 aircraft in its fleet until mechanics could carefully inspect each plane. Later Saturday, the FAA ordered the temporary grounding of planes in some other airlines' fleets. United Airlines had the most affected aircraft with 79 Max 9s.
Late Saturday, Jennifer Homendy, chairwoman of the National Safety Transportation Board, the body responsible for investigating plane crashes, said that a plug on one of the plane's unneeded emergency doors came off 10 minutes from the airport while the plane was at an altitude of about 16,000 feet.
Ms. Homendy said investigators would compare the plug from a second emergency door at the other end of the hallway to the plug that burned out in hopes of figuring out what went wrong. She added that investigators would also look at things like the plane's pressurization system and maintenance records.
Jessica Kowal, a spokeswoman for Boeing, said in a statement: “We agree with and fully support the FAA's decision to require immediate inspections of 737-9 aircraft with the same configuration as the affected aircraft.”
And while the particular problem that led to Friday's scares seemed unique, Boeing's 737 Max planes have perhaps the most troubling history of any modern airliner currently in service.
What happened on Friday?
Alaska Airlines Flight 1282, carrying 171 passengers and six crew bound for Ontario, California, landed at Portland Airport 20 minutes after takeoff Friday evening.
Passengers on the flight reported hearing a loud noise before noticing part of the fuselage opening in mid-air.
In the minutes before the emergency landing, as oxygen masks hung from the ceiling and the wind howled through the gaping hole in the wall, passengers were unable to hear urgent announcements over the public address system.
The aircraft involved in Friday's incident was virtually new by commercial airline standards. It was first registered in November and had only logged 145 flights.
What is the history of the 737 Max?
Two crashes involving Boeing 737 Max 8 aircraft killed a total of 346 people in less than five months in 2018 and 2019. Both crashes were later linked to a malfunction in the system that overrode the pilot's orders.
Those crashes led to a global grounding of Boeing 737 Max planes, leaving hundreds of planes parked on tarmacs around the world for nearly two years while engineers worked to identify and resolve the problem so that regulators could restart the planes could allow.
The first crash occurred in October 2018, when a passenger plane carrying 189 people from Jakarta, Indonesia, plunged into the Java Sea just minutes after takeoff. Four months later, another 737 Max, this time from Ethiopian Airlines, crashed immediately after takeoff en route to Addis Ababa, killing all 157 people on board, including the flight's eight crew members.
Days later, President Donald J. Trump announced that American regulators would temporarily halt all Boeing 737 Max flights while investigators and Boeing tried to determine what role a software system designed to make the plane safer played in the disasters.
U.S. regulators were among the last to ban the model, but did so after pressure mounted and 42 other countries took drastic steps to prevent further crashes.
Reports from the New York Times and others eventually revealed that competitive pressures, flawed design and problematic oversight had played a role in the troubling history of the plane, Boeing's best-selling jet of all time and one with hundreds of billions of dollars in pre-orders from airlines around the world it was grounded.
What was the fallout?
Boeing agreed to pay $2.5 billion as part of a 2021 settlement with the Justice Department to resolve a criminal charge that Boeing conspired to defraud the Federal Aviation Administration, which regulates the company and its Aircraft rated.
In 2022, Boeing paid $200 million more in a deal with U.S. securities regulators over allegations that the company misled investors by blaming human error for the two fatal crashes and the company's concerns about of the aircraft was ignored.
When the planes were recertified 20 months after the crashes in Indonesia and Ethiopia, Boeing estimated that the crisis had cost the company $20.7 billion.
Which airlines use the 737 Max 9?
Part of Boeing's single-aisle 737 Max series, the Max 9 can carry up to 220 passengers, depending on seating configuration. United Airlines has 79 Max 9s in service, more than any other airline, according to Cirium, an aviation analytics firm. A total of 215 Max 9 aircraft are in use worldwide, Cirium said. United and Alaska Airlines have about a third of that.
Other companies flying the Max 9 include Copa Airlines from Panama and Aeromexico in America, SCAT Airlines from Kazakhstan, Island Air, Turkish Airlines and FlyDubai.
A spokesman for FlyDubai said the three 737 Max 9 aircraft in its fleet had completed their necessary safety checks in the last 24 months and that the company was awaiting guidance from Boeing before conducting further inspections.
What happens next?
Serious aviation safety incidents, including those that do not result in injury or loss of life, typically result in immediate reviews by regulators in the United States, the European Union and China.
Investigators look at everything: the design of the plane; its manufacturing, maintenance and inspection history; Weather; air traffic control decisions; and actions of the flight crew. They look for causes of an incident as well as lessons for aviation safety.
In the case of the Alaska Airlines incident, the aircraft was manufactured in the USA and lost a fuselage part while flying in the USA. Therefore, the National Transportation Safety Board will be the lead agency responsible for investigating the incident.
Security investigations can take many months. They involve technical experts from the government, the airline that operated the plane, unions and the aircraft manufacturer – in this case Boeing.
The FAA does not have to wait for the safety committee's report before deciding whether to ground a model aircraft or order immediate inspections. Airlines usually check their planes quickly anyway once they know what to look for.
What does the flight ban mean for air travelers?
The grounding of one of the industry's main workhorses could put a strain on travelers as airlines sometimes have to cancel flights because they lack the planes to replace the flight model.
According to FlightAware, a flight tracking website, United had canceled 253 flights, or 9 percent of its daily schedule, as of Sunday afternoon, although some of those cancellations may also have been due to poor winter weather in the Northeast.
Alaska Airlines had canceled 163 flights, or 21 percent of its schedule, as of Sunday afternoon.
Alaska has issued a “system-wide flexible travel policy” that allows passengers to cancel or change their flights without incurring fees. The airline encourages travelers to use the Alaska website or app themselves rather than calling the airline's customer service line.
United flight status updates can be found online. If a flight experiences significant delays, United will waive change fees or provide a travel credit or refund. The airline has not granted a specific exemption related to aircraft inspections that would result in further relaxation of the guidelines.
And if a flight is delayed or canceled, the traveler may be entitled to compensation, depending on the circumstances.