25 October, 2019
Indonesian investigators say a combination of design problems and other issues were to blame for a Boeing 737 Max 8 jet crashing shortly after it left Jakarta last year. The investigation found that a lack of pilot training and poor flight crew performance also were partly responsible for the crash.
All 189 people on the plane were killed.
A summary version of the final report said the pilots did not know how to react to problems in the plane's automated flight-control system.
The Indonesian government has yet to release the full report.
The investigators identified nine problems that they believe were responsible for the deadly crash.
Chief investigator Nurcahyo Utomo told reporters that, "If one of the nine had not occurred, maybe the accident wouldn't have happened."
The airplane belonged to the Indonesian company Lion Air, a low cost carrier. On October 29, 2018, the Boeing 737 Max 8 disappeared from radar after the pilots told air traffic controllers that the plane was not gaining altitude and speed as it should.
Five months later, a similar situation happened on the same kind of Boeing jet in Ethiopia. That plane also crashed, killing 157 people.
After the Ethiopian crash, Boeing was put under intense pressure to explain what had happened. Many countries barred the 737 Max 8 from their airspace.
A short time later, all Max 8 jets were banned from flying and they have yet to return to service. The problems with the jets have brought attention to the safety certification process in the United States.
What happened on the Lion Air flight?
Indonesia's National Transportation Safety Committee said the flight control system, known as the MCAS, on the Max 8 was poorly designed. It noted that the MCAS system depends on a single "angle of attack" sensor. This instrument recognizes if the plane is pointing up or down. The committee considered this a design mistake.
The head of the committee said in a statement that "The aircraft flight manual and flight crew training did not include information about MCAS."
The summary version also pointed to other problems that led to the crash.
The airplane that crashed had only been in use for two months, but days before the crash it began having problems. Workers installed a new "angle of attack" sensor in the plane while it was in Bali one day before the crash. However, the instrument had been mis-calibrated during an earlier repair. Investigators said they were unable to find out if the new sensor had been tested.
Then, soon after the Max 8 left Bali on a flight to Jakarta, the plane's instruments warned of problems related to airspeed and altitude. The captain and the co-pilot regained control of the plane by turning off the automated control system. They then continued on to Jakarta, but did not fully report the problems, the summary said. So Lion Air maintenance crews did not investigate.
Aviation expert Gerry Soejatman said that the flight from Bali to Jakarta was lucky. He said most of the blame should be placed on Boeing, the plane's manufacturer.
The American company released a statement Friday. Boeing said it was working to consider all the safety recommendations to prevent a similar problem. The company said it has redesigned the flight control system to operate using two sensors.
The U.S. Federal Aviation Administration (FAA) welcomed the recommendations from the investigation.
I'm Mario Ritter Jr..
Mario Ritter Jr. adapted this Associated Press story for VOA Learning English. George Grow was the editor.
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Words in This Story
summary – n. a shorter version of a document that gives the most important information
automate – adj. self-operating or robotic
occur – v. to happen
altitude – n. the height of something above the level of the sea
certification – n. documentation; a written guarantee
manual – n. a document or booklet that tells how to use something
install – v. to make something ready for use by putting everything in place and making changes
mis-calibrate – v. to make a bad or wrong measurement
aviation – n. related to or involving the operation of airplanes
recommendation – n. suggestion; proposal
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