The prestige of Ethiopian Airlines, one of Africa's most successful companies, and Boeing, the world's biggest planemaker and a massive US exporter, is at stake in the inquiry.
Following the Ethiopian Airlines crash - the second crash of a 737 Max 8 plane in less than five months - countries and airlines around the world grounded their 737 Max planes. "We can't provide additional comment at this stage due the ongoing investigation on the accident", Lion Air spokesman Danang Prihantoro said by phone. The jet came down in the Java Sea shortly after leaving Jakarta, Indonesia's capital.
Experts have pointed to similarities between the Lion Air crash six months ago and last week's Ethiopian Airlines crash, which killed all 157 people on board.
The automated system attempts to prevent the plane from stalling on takeoff. By that time, the investigators had already released an initial report of the accident, which relies heavily on flight data captured by the FDR.
Meanwhile, the investigation into the final minutes of Ethiopian Airlines Flight 302 turned on Tuesday to the secrets in the cockpit voice recorder as Boeing and a shaken global aviation industry hung on the outcome.
Sources said that the captain fought to climb, but the computer, still incorrectly sensing a stall, continued to push the nose down using the plane's trim system located in the tail of the aircraft.
FILE PHOTO: A seal is seen on Garuda Indonesia's Boeing 737 Max 8 airplane parked at the Garuda Maintenance Facility AeroAsia, at Soekarno-Hatta International airport near Jakarta, Indonesia, March 13, 2019. They believe it was because of a sensor that did not work correctly.
Now it appears that pilots of the penultimate flight have too struggled to control the aircraft.
Boeing has said there was a documented procedure to handle the problem. It also said the pilot and co-pilot are supposed to understand the process. When the angle of attack sensor caused the aircraft to trim the nose down, his ability to recommend a solution meant the plane arrived at its destination safely. Bloomberg reported that the crew members got help from an off-duty pilot, who was on the same flight.
The FBI's Seattle field office lies in proximity to Boeing's 737 manufacturing plant in Renton, as well as nearby offices of Boeing and Federal Aviation Administration (FAA) officials involved in the certification of the plane. Now they will seek their own answers. Fatally, the pilot and co-pilot on that day had no knowledge of how to rectify the problem.
The 31-year-old captain then asked the first officer to check the quick reference handbook, which contains checklists for abnormal events.
Various firms are reconsidering Boeing orders, and some airlines are revising profit forecasts given they now can not count on maintenance and fuel savings factored in from the MAX.
For now, regulators have grounded the existing fleet of more than 300 MAX aircraft and deliveries of almost 5,000 more-worth well over $500 billion-are on hold. Boeing's plans to sell almost 5,000 others are on hold.
The MAX, which offers cost savings of about 15 per cent on fuel, was developed for service from 2017 after the successful launch by its main rival of the Airbus A320neo.
Ethiopia's civil aviation head Wosenyeleh Hunegnaw told Reuters he expected a report on the investigation within 30 days. George Grow was the editor. Susan Shand adapted it for VOA Learning English.
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