Accident investigators are trying to figure out why a Jeju Air flight belly-landed Landing gear not lowered A fire broke out at Muan International Airport in southwestern South Korea, causing the country’s worst air crash in decades, killing all but two of the 181 people on board.

Acting President of South Korea Choi Sang-mok orders a state of emergency examine national boeing company 737-800s, the type used on the fatal Jeju Air flight 7C2216.

The Boeing 737-800 is one of the most commonly used aircraft in the world and has a good safety record. It predates the Boeing 737 Max, which model participated in two fatal accidents In 2018 and 2019, all 346 people on these flights died. 737 Max is Grounded for nearly two yearsand later adjusted flight control systems related to these two accidents.

There are nearly 4,400 older Boeing 737-800 aircraft in operation worldwide, according to aviation data company Cirium. This means that this aircraft type accounts for approximately 17% of the world’s active commercial passenger aircraft fleet.

According to Cirium, the average age of the global 737-800 fleet is 13 years, with the last aircraft in the series delivered about five years ago.

Jeju Air took delivery of the plane involved in this weekend’s crash in 2017. According to Flightradar24, the plane was previously operated by European budget airline Ryanair. The plane that crashed was about 15 years old.

Aerospace experts said it was unlikely investigators would find design problems with the long-haul plane.

“The idea that they would find a design flaw at this point is almost unthinkable,” said Richard Aboulafia, managing director of aerospace consultancy AeroDynamic Advisory.

A full investigation could take more than a year, and the unusual incident raises more questions than answers, such as why the landing gear was not deployed. Even in the event of a hydraulic failure, Boeing 737-800 pilots can manually lower the landing gear.

One theory is that a bird strike may have disabled at least one engine, if not both.

“If this had happened at the altitude they were at, they might not have had time to do an emergency checklist,” said Jeff Guzzetti, a retired aviation safety investigator with the National Transportation Safety Board and the Federal Aviation Administration. , if the plane had not hit the dirt and hard wall at the end of the runway, the accident survival rate might have been higher. This area houses positioners that help guide the aircraft.

The NTSB leads the U.S. investigative team, which also includes boeing company and the FAA because the aircraft is manufactured and certified in the United States.

Under international agreements, the country where the accident occurred will lead a comprehensive investigation.

Boeing shares fell more than 4% in early trading Monday after local officials released the news. request inspection Korean Airlines operates 737-800 aircraft, but recouped earlier losses to close down 2.3%.