Sign up for our daily briefing

Make your busy days simpler with Axios AM/PM. Catch up on what's new and why it matters in just 5 minutes.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Catch up on coronavirus stories and special reports, curated by Mike Allen everyday

Catch up on coronavirus stories and special reports, curated by Mike Allen everyday

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Denver news in your inbox

Catch up on the most important stories affecting your hometown with Axios Denver

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Des Moines news in your inbox

Catch up on the most important stories affecting your hometown with Axios Des Moines

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Minneapolis-St. Paul news in your inbox

Catch up on the most important stories affecting your hometown with Axios Twin Cities

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Tampa Bay news in your inbox

Catch up on the most important stories affecting your hometown with Axios Tampa Bay

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Charlotte news in your inbox

Catch up on the most important stories affecting your hometown with Axios Charlotte

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

A United Airlines Boeing 737 Max 9 aircraft lands at San Francisco International Airport on March 13. Photo: Justin Sullivan/Getty Images

With the global fleet of the brand new Boeing 737 MAX jet grounded indefinitely after two deadly crashes, we're learning more about what may have brought us to this point.

Why it matters: No plane crash is ever the result of one factor alone, but rather a series of events that conspire to cause a disaster.

  • In the case of the Lion Air crash in October and the Ethiopian Airlines crash last week, the information coming from the official crash investigations is focused squarely on a system built into the aircraft to prevent it from stalling, or running out of lift.
  • Another emerging thread from the investigation is the way that the plane — which has a total of more than 5,000 standing orders from carriers worldwide — was certified to fly in the first place.

How it works: Media outlets have been shining a spotlight on how the plane came to be approved as if it was simply another version of the best-selling 737 series, despite having so many new pieces of hardware. That includes new, more powerful engines, a redesigned tail, new wing design and more, along with complex, novel software.

  • The MAX’s larger, more powerful engines are strapped farther forward on its wings compared to other 737 derivatives, which changed the aerodynamic characteristics of the plane and could push the nose upward in certain situations.
  • Boeing installed software, known as the Maneuvering Characteristics Augmentation System, or MCAS, to push the nose down and avoid a high speed stall. But this system gets its input from just a single angle of attack sensor mounted near the nose of the aircraft.
  • It's this system that is suspected of causing the two crashes, potentially due to faulty data from the angle of attack sensor.
  • Had the MCAS compared data from both of the angle of attack sensors on the plane, it could have ignored erroneous data from one of them.

Context: Despite the aerodynamic differences and new software system, many 737 pilots were not required to undergo intensive training in flight simulators, and they could instead do so on an iPad, according to the New York Times. The simulators also weren't ready when the plane began rolling out of the factory and taking to the sky.

  • The lack of simulator training was a selling point for the jet, since it meant airlines that already flew other versions of the 737 could save money on training.
  • The NYT reported that pilots at United Airlines, which flies the Boeing 737 MAX 9, were not initially trained on the MCAS system.

Meanwhile: Another strand emerging from the accident investigations concerns how deferential the FAA was to Boeing in certifying the MCAS system and other aspects of the plane's certification.

  • The Seattle Times reports that deadline pressure prodded the FAA and Boeing to delegate more safety decisions to Boeing engineers working on behalf of the FAA. That's because across the Atlantic, Boeing's arch-rival company, Airbus, was developing a similar plane, known as the Airbus A320neo.
  • The Times story also shows that the original safety assessment for the MCAS system may have misstated its full capability in moving the tail of the plane, as well as how many times it could kick in before resetting.
  • A federal grand jury issued a subpoena on March 11 to at least one person involved in the development of Boeing's 737 MAX aircraft on behalf of the Justice Department, though it remains unclear if the action is related to government scrutiny of the FAA's approval of the plane's MCAS anti-stall safety system, the Wall Street Journal reports.

What's next: Boeing has said it plans to roll out a fix to the MCAS software in April that should prevent a similar crash in the future. But it's likely that pilots will be briefed on it via additional personal computer training, since there is just one 737 MAX simulator available for training use in the U.S.

CEO Dennis Muilenburg issued a new statement on Sunday:

"While investigators continue to work to establish definitive conclusions, Boeing is finalizing its development of a previously-announced software update and pilot training revision that will address the MCAS flight control law's behavior in response to erroneous sensor inputs."

Editor's note: This story has been updated to include the WSJ report of a federal criminal investigation.

Go deeper:

Go deeper

Biden will reverse Trump's attempt to lift COVID related travel restrictions

Photo: Tasos Katopodis via Getty

The incoming Biden administration will reverse President Trump's last-minute order to lift COVID-19 related travel restrictions, Jen Psaki, the incoming White House press secretary, tweeted.

Why it matters: President Trump ordered entry bans lifted for travelers from the U.K., Ireland, Brazil and much of Europe to go into effect Jan. 26, but the Biden administration will "strengthen public health measures around international travel in order to further mitigate the spread of COVID-19," Jen Psaki said. Biden will be inaugurated on Wednesday, Jan. 20 and Trump will no longer be president by the time the order is set to go into effect.

Dominion sends cease and desist letter to My Pillow CEO Mike Lindell

Photo: Stephen Maturen/Getty Images

Dominion Voting Systems on Monday sent a cease and desist letter to My Pillow CEO Mike Lindell over his spread of misinformation related to the 2020 election.

Why it matters: Trump and several of his allies have pushed false conspiracy theories about the company, leading Dominion to take legal action. It's suing pro-Trump lawyer Sidney Powell for defamation and $1.3 billion in damages, and a Dominion employee has sued Trump himself, OANN and Newsmax.

Off the Rails

Episode 5: The secret CIA plan

Photo illustration: Aïda Amer, Sarah Grillo/Axios. Photo: Zach Gibson/Getty Images

Beginning on election night 2020 and continuing through his final days in office, Donald Trump unraveled and dragged America with him, to the point that his followers sacked the U.S. Capitol with two weeks left in his term. This Axios series takes you inside the collapse of a president.

Episode 5: Trump vs. Gina — The president becomes increasingly rash and devises a plan to tamper with the nation's intelligence command.

In his final weeks in office, after losing the election to Joe Biden, President Donald Trump embarked on a vengeful exit strategy that included a hasty and ill-thought-out plan to jam up CIA Director Gina Haspel by firing her top deputy and replacing him with a protege of Republican Congressman Devin Nunes.