A Chinese airplane with 123 passengers and nine crew members crashed on Monday in the southern province of Guangxi, and officials started conducting rescue efforts at the site of the downed aircraft.
Data from the flight tracking website FlightRadar24.com shows the China Eastern flight was traveling at about 30,000 feet at a cruising speed of 523 mph before it dropped.
The crash ignited a fire near the city of Wuzhou in Teng county, and hundreds of firefighters and rescuers were sent to the scene and the fire was extinguished, according to the state-run China Daily. The outlet also reported that a village official with the surname Zhou said that the plane had "completely disintegrated" and that he did not see any remains.
Chinese President Xi Jinping called for an "all-out effort" in rescue operations and urged that any safety hazards that could have caused the crash to be investigated.
The aircraft was a Boeing 737-800. Though Boeing has come under fire for crashes in recent years, it was the company's Boeing 737 Max that generated some of the harshest criticism.
There are differences in the aircraft, and Aerovise aviation expert Josh Verde told USA TODAY the Boeing 737-800 is a "tremendously safe airplane." Most accidents involving the plane have been runway-related.
In 2010, an Ethiopian Airlines flight, a Boeing 737-800, crashed into the Mediterranean Sea, and 98 people were killed.
Here's what we know about the Boeing 737-800:
Chinese airline crash: Search continues for 132 people on board Boeing 737 that crashed in southeast China
How many Boeing 737-800 planes are in use today?
The Boeing 737-800 has been in use for nearly 20 years, and Verde said the plane is one of the most common used around the world, primarily in the United States, Europe and Asia.
Southwest Airlines, the nation’s largest domestic carrier, flies Boeing 737s exclusively and had 728 in its fleet at the end of 2021. That included 207 Boeing 737-800s with an average age of 6 years.
American Airlines had 267 737-800s; United had 141 and Delta had 77. In total, the four major U.S. airlines have nearly 700 of the jetliners in their fleets.
Verde estimates that there are about 200 Boeing 737-800s in the air in the U.S. at any given time.
What's the difference between a Boeing 737-800 and a Boeing 737 Max?
The Boeing 737 Max was heavily scrutinized after two international planes crashed in 2018 and 2019, resulting in 346 deaths. The plane was grounded worldwide and wasn't allowed to fly until several changes were made and it was recertified by the Federal Aviation Administration, which it did in December 2020.
The aircraft is used in the United States, but David Yu, a finance professor specializing in aviation at New York University in Shanghai, told The New York Times the planes are not back in service in mainland China yet.
Anthony Brickhouse, associate professor of applied aviation sciences at Embry-Riddle Aeronautical University, told USA TODAY the key difference in the Max is that its engines are located in a different spot and the Max is more fuel-efficient.
"I would encourage people not to automatically connect the dots between what happened today and what happened back in 2018 and 2019," Brickhouse said.
Is the Boeing 737-800 safe?
The 737-800, part of Boeing's next-generation family, has had some issues in recent years. In 2019, the FAA ordered the inspection of heavily used 737 NGs for cracks in wing supports, which found several planes had wing cracks.
But Verde said the planes "don't have any ongoing areas of concern" and have had long, safe track records, alluding to how many airline companies use them today. He added the Boeing 737 Max was the first time he had seen the company cause a public scare.
"They're tremendously safe airplanes, and so the public certainly shouldn't have any concerns about getting on board one," Verde said.
Brickhouse said it's normal for people to feel uncertain about flying after a passenger plane crashes but said the jetliner is still reliable and safe, and investigations into the crash will lead to any changes being made.
What could have caused the Chinese plane to crash?
Video taken of the flight showed the plane in a straight nosedive moments before its impact, something Verde said could indicate the flight crew lost control of the plane. He said the impact would have been "tremendous," and there's no guarantee anything on the plane, including the black box, would survive.
"Systems problems or a failure of some type is typically the only time you would see a plane in that nose-down dive of attitude when you're talking about an airliner," Verde said.
"The cause of the plane crash is still under investigation, and the company will actively cooperate with relevant investigations," the airline said in a statement Monday. "The company expresses its deep condolences to the passengers and crew members who died in the plane crash."
Brickhouse, a former student trainee at the National Transportation Safety Board, said one thing that caught his attention was the aircraft's sudden drop. The plane dropped from 30,000 feet to about 9,000 feet in under three minutes.
"That's not your typical descent rate for an aircraft," he said.
There is no timetable of when it will be known what caused the crash, but Brickhouse said investigators don't focus on one piece of evidence alone, and the evidence and data will help determine what caused the crash.
Contributing: Ryan Miller, Dawn Gilbertson
Follow Jordan Mendoza on Twitter: @jordan_mendoza5.
This article originally appeared on USA TODAY: A Boeing 737 crashed in China. Are Boeing planes safe?