Flight data shows jets suffered the same failures
The Ethiopian Boeing that crashed last week suffered the same failure that brought down an Indonesian airliner of the same model in October, according to the first data from the flight recorders.
A report from the Ethiopian transport ministry strengthened suspicion that a dive commanded by a rogue stabiliser on the new Boeing 737 Max 8 ended Ethiopian Airlines Flight 302 just after take-off from Addis Ababa on March 10, killing 157 people.
All Max 8 737s were grounded last week because the Ethiopian jet had experienced a similar erratic climb as the Indonesian Lion Air Max 8 that crashed into the Java Sea, killing 189 people.
‘‘Clear similarities were noted between Ethiopian Airlines Flight 302 and Indonesian Lion Air Flight 610,’’ Dagmawit Moges, Ethiopia’s transport minister, said.
The flight data recorder, downloaded by French experts in Paris, had yielded good information, he said. ‘‘The data was successfully recovered,’’ Muse Yiheyis, an Ethiopian ministry spokesman, said. ‘‘The American team and our Ethiopian team validated it. The minister thanked the French government.’’
The data hardened belief that a faulty design involving the Boeing’s new stabiliser system, called the Manoeuvring Characteristics Augmentation System (MCAS), was at the heart of the two crashes. It has emerged from the Ethiopian wreckage that the ‘‘jackscrew’’, a heavy metal mechanism that commands the tail stabiliser, had been set in a heavy nose-down position.
Facing criticism, Boeing and the Federal Aviation Administration (FAA), its regulator, have insisted that the 737-Max met all safety standards. However, a new report yesterday quoted staff at Boeing and the FAA, who said that the MCAS system had been rushed into service with flaws that slipped through the certification process.
Boeing’s safety analysis of the jet, designed to compete with the Airbus A320, understated the power of the automated MCAS, which was designed to assist pilots in manually controlled flight. When the aircraft entered service the MCAS had power to move the stabiliser more than four times farther than was stated in the initial analysis, according to an investigation by The Seattle Times, the local paper at Boeing’s historic base. Boeing’s safety analysis, accepted by the FAA, ‘‘failed to account for how the system could reset itself each time a pilot responded, thereby missing the potential impact of the system repeatedly pushing the airplane’s nose downward,’’ the newspaper said.
A former FAA safety engineer involved in the Max 8 said: ‘‘There wasn’t a complete and proper review of the documents. The review was rushed to reach certain certification dates.’’
Peter Lemme, a former Boeing flight controls engineer, told the newspaper that although pilots were supposed to be able to use their controls to override the downward push of the MCAS ‘‘it had full authority to move the stabiliser the full amount ... Nobody should have agreed to giving it unlimited authority.’’