More key crash evidence found
A new piece of evidence found by investigators suggests that the Ethiopian Airlines flight that crashed this week may have had a problem with a new flight control system also suspected in the crash of a Lion Air flight in Indonesia last October.
It is the second piece of information suggesting similarities between the two crashes involving Boeing 737 Max 8 jets.
Investigators found a device known as a jackscrew in the wreckage. The jackscrew, used to set the trim that raises and lowers the plane’s nose, indicated that the jet was configured to dive, according to John Cox, a former pilot and an airline safety consultant with Washington-based aviationsafety consulting firm Safety Operating Systems.
Cox, formerly the top safety official for the United States Air Line Pilots Association, said he was privately briefed on the evidence by people familiar with the investigation.
‘‘All we can say definitely is that the trim was in a position similar to the position found on the Lion Air airplane, and it would cause the nose to go down,’’ he said. ‘‘This will be consistent with a nose-down flight path, which they think is likely with the Ethiopian airplane.
‘‘It points to one central link,’’ Cox said. ‘‘We need the data from the flight data recorders. We need it as quickly as possible . . . The faster that we get that information, it will let everyone know what needs to be done.
‘‘We don’t know in fact if these accidents are related. There are some similarities.’’
Daniel Elwell, acting administrator of the US Federal Aviation Administration (FAA), cited newly refined satellite tracking data and evidence recovered from the crash site as factors in his decision to ground the jets. That data also showed similarities to the Lion Air flight.
Cox said he believed the jackscrew was the new evidence Elwell was citing.
Meanwhile, French aviation experts began work yesterday on the plane’s heavily damaged data and voice recorders.
Officials with France’s Bureau d’Enquites et d’Analyses, which has extensive experience analysing air crashes in Europe, said work to retrieve information from the flight data recorder had begun in coordination with the Ethiopian investigation team.
The data extracted from the recorders will be used to reconstruct the six-minute flight before the plane crashed in a farm field about 65km from Addis Ababa, killing all 157 passengers and crew on board.
Officials from the US National Transportation Safety Board (NTSB), the FAA, the European Union Aviation Safety Agency and Boeing also are assisting with the investigation.
Experts say it typically takes almost a month to provide a comprehensive analysis of the data in the recorders.
Former NTSB chairman Christopher Hart, who is also is a pilot, said the jackscrew, combined with data gathered from the plane’s black box, could give investigators a sense of the plane’s flying position before the crash.
In a preliminary investigation, the crash of a Lion Air Max 8 plane into the Java Sea on October 29 was attributed to a faulty sensor causing an automated system to push the plane’s nose down. The possibility that the same scenario occurred in Ethiopia has prompted precautionary groundings of the plane all over the world.
Preliminary flight data showed the Ethiopian Airlines plane in trouble almost immediately and struggling to gain altitude in the high, thin air above Addis Ababa’s airport. The plane descended and then sharply ascended, while moving at speeds far in excess of normal.
Within minutes, the pilot radioed the control tower reporting ‘‘flight control’’ problems, and was given clearance to return.
In the case of the Lion Air crash, faulty information from the angle-of-attack sensor convinced the automated system that the plane was going to stall, and pushed its nose down while the pilots wrestled to pull the aircraft up.
The result was an erratic flight path in which the plane descended and ascended repeatedly before plunging into the sea, killing all 189 passengers and crew on board.
The data from the recorders in Ethiopia could help to determine whether the potential links between the two crashes are real and related to the automated feature on the 737 Max 8. – Washington Post