You could be onboard one of Boeing's most notorious planes by the end of the year.

The aircraft manufacturer has started the process to regain Federal Aviation Administration certification for its 737 Max 8 jets, Boeing CEO Dennis Muilenburg told CNBC on Monday. Boeing recently issued a software update for the aircraft's flawed anti-stall system, and now Muilenburg says it should be back in use for commercial airlines by the end of the year.

737 Max 8 planes were grounded around the world in March after two of them crashed, killing 346 people total. A series of reports later tied the crashes to other reported issues with the model's anti-stall mechanism and suggested Boeing was aware of the flawed technology but didn't move quickly to fix it.

The FAA now has to recertify the aircraft before it can get back in the air. Boeing has scheduled simulated flights with the FAA for this week, Muilenburg said, and added that "we hope to schedule the certification flight very soon." The FAA would then decide if the Max 8 planes are skyworthy. So far in the regulatory process, the FAA found that more than 300 Boeing 737 jets had faulty wing parts that need to be replaced before they can fly again.

Watch Muilenburg's whole CNBC interview below. Kathryn Krawczyk

Rev. Donna Beasley is still fighting for justice, decades after she marched through the streets of Louisville, Kentucky, with Martin Luther King, Jr.

Beasley on Wednesday joined protesters who came out in force to condemn racism and police brutality. She told MSNBC's Cal Perry that "black people have been fighting this fight for years, hundreds of years, and it's a shame that in 1962 to 2020, I'm still seeing the same thing, we're still having to fight to be treated like we're normal, regular human beings."

One thing has changed, and that's the diversity in the crowd. "I'm glad to see all the whites who are out here protesting with us as we march down the street," Beasley said. "I'm glad to see that. That's the way it should have been a long time ago, walking hand in hand, arm in arm. That's what Martin Luther King preached about and wanted, but unfortunately his dream has not been totally realized."

After so many years of protesting and demanding change, "We're just tired of the struggle," Beasley said. "We're tired of the fight. We're tired of being treated like we're subservient, that we're less than, like we're dirt under people's feet." She suggests young protesters study tactics that civil rights activists used in the 1960s, like sit-ins, and start talking with city and state leaders. "But talk is cheap," she added. "We can talk all day long, but if we get up and you go your way and I go my way and nothing's ever done, then that's just a wasted conversation."

Beasley marched with King in 1962. He would often come to Louisville because his brother, Rev. A.D. Williams King, was a religious and civil rights leader in the city, and together they would march and attend rallies. Catherine Garcia

Using a remote sensing method, scientists working in southern Mexico found an ancient structure that has a total volume exceeding Egypt's Great Pyramid of Giza.

The discovery in Aguada Fénix is the largest and oldest-known structure built by the Maya civilization, Reuters reports. A rectangular elevated platform made of clay and earth, it was built between 1000 and 800 BC, is nearly a quarter-mile wide and nine-tenths of a mile long, and stood 33 to 50 feet high.

Researchers used Light Detection and Ranging, or Lidar, to find the structure. Lidar is a remote sensing method used to examine the surface of the Earth and measure ranges. This technique uses laser light and other data recorded by an aerial system to generate three-dimensional information about the surface.

University of Arizona archeologist Takeshi Inomata led the research, published Wednesday in Nature, and told Reuters the structure is "so large horizontally, if you walk on it, it just looks like natural landscape." Researches believe it was used "for special occasions, possibly tied to calendrical cycles. The rituals probably involved processions along the causeways and within the rectangular plaza. The people also deposited symbolic objects such as jade axes in the center of the plateau." Catherine Garcia

President Trump responded to Wednesday's blistering rebuke from former Defense Secretary James Mattis by attacking the reticent retired four-star Marine general in two factually challenged tweets.

Mattis, who retired from the military in 2013, sent a statement to The Atlantic on Wednesday lambasting Trump's leadership. He argued that Trump ordered U.S. military personnel to violate the Constitution for his "bizarre photo op" in front of a church, said he hasn't offered "mature leadership," and compared Trump's content attempts to "divide us" to the Nazi "divide and conquer" ethos. "We do not need to militarize our response to protests," Mattis wrote. "We need to unite around a common purpose. And it starts by guaranteeing that all of us are equal before the law."

Trump, recycling old attacks, called Mattis "the world's most overrated general," stated incorrectly that he fired him — Mattis resigned in protest of Trump's decision to pull U.S. forces out of Syria, abandoning Kurdish allies — and claimed falsely that he was the one who gave Mattis the hated nickname "Mad Dog."

Mattis and Trump never had a great working relationship, but after resigning with a dryly critical letter, he told The Atlantic there's "a period in which I owe my silence" to the president and his former colleagues, but "it's not eternal. It's not going to be forever." The period is evidently over, and there may be more to come.

Mattis isn't the only retired military leader criticizing Trump's military deployment in the capital and threat to send active-duty troops to other cities — former Joint Chiefs chairmen Adm. Mike Mullen and Martin Dempsey criticized Trump's military response to lawful protests on Tuesday, and a former top Pentagon official, James N. Miller, resigned from the Defense Science Board in protest. Peter Weber

Tropical Storm Cristobal made landfall on Wednesday near Atasta in the Mexican state of Campeche, bringing heavy rain that is expected to last through Thursday.

The storm formed Tuesday from the remnants of Pacific Tropical Storm Amanda, which left 22 people dead in Guatemala and El Salvador. At least 138 people were evacuated from Campeche by the Mexican army, due to high floodwaters. Forecasters say Cristobal will likely become a tropical depression by Thursday, before moving back to the Gulf of Mexico on Friday.

Cristobal could reach the U.S. Gulf Coast on Sunday, but the U.S. National Hurricane Center said "the model guidance currently suggests that the atmospheric environment over the Gulf will not be very conducive for strengthening." Catherine Garcia

California Gov. Gavin Newsom (D) is calling President Trump's threat to send the military to major cities "just another zig and zag deflection from the administration."

On Monday, Trump warned that if governors and mayors didn't do enough to quell protests, he would send "thousands and thousands of heavily armed soldiers, military personnel, and law enforcement officials" to cities. Newsom brushed aside the threat, telling reporters on Wednesday, "It won't happen. It's not going to happen. We would reject it. We would push back against that."

Following requests from mayors like Eric Garcetti of Los Angeles, Newsom has deployed 2,600 California National Guard troops to some parts of the state. Catherine Garcia

AMC, the largest theater chain in the U.S., said Wednesday it may not be able to survive the coronavirus pandemic.

AMC theaters were shut down in March, and the chain said in a regulatory filing that it has enough cash to reopen all of them in the summer, but if that can't happen, it will need more money.

The company listed several concerns, including whether customers are even going to want to return to theaters during the pandemic. Since March, some new movies have been released to streaming platforms for at-home viewing, and AMC and other theater chains are worried this practice will continue in the future. Because Hollywood has stopped production on movies, it will also take time before there are full slates of new films.

Due to all of this, AMC expressed "substantial doubt" of its "ability to continue" for an extended period of time. The company has 1,000 theaters in the U.S. and Europe. Catherine Garcia