Ethiopia’s transport minister says there were altitude fluctuations in the minutes after take-off during two doomed flights.
There are “clear similarities” between the accidents involving Ethiopian Airlines and Lion Air aircraft, Ethiopia’s transport minister has said following a study of flight data.
The Ethiopian carrier’s data recorders are currently being analysed by experts in Paris but a preliminary report on what they contain may not be released for another month.
However, a week after the latest tragedy, which like the Lion Air crash involved a new Boeing 737 MAX 8 aircraft, transport minister Dagmawit Moges pointed to altitude fluctuations in the minutes after take-off during both flights.
“Clear similarities were noted between Ethiopian Airlines Flight 302 and Indonesian Lion Air Flight 610, which would be the subject of further study during the investigation,” Ms Dagmawit told journalists on Sunday.
In both cases, flight tracking data show the planes’ altitude wavered sharply as the pilots struggled to deal with erratic climbs and descents.
Dennis Muilenburg, chairman and chief executive of Boeing, has reaffirmed that the aircraft manufacturer is supporting the investigation.
Boeing is pressing ahead with a software update that will fix the behaviour of the flight control system “in response to erroneous sensor inputs,” he added.
Meanwhile, ceremonies are taking place both in Kenya and Ethiopia to honour the victims. Burials are being conducted using earth taken from the crash site, as it could take months to identify the victims’ remains.
Minutes into the Ethiopian Airlines flight, the pilot reported difficulties and asked to return to Addis Ababa airport.
The air traffic monitor Flightradar24 says the plane’s “vertical speed was unstable after take-off”. Soon afterwards, the aircraft hit the ground at high speed.
Though the investigation is ongoing, it seems increasingly likely that it is the Maneuvering Characteristics Augmentation System (MCAS) flight control system that is behind both air disasters.
This was designed to prevent Boeing’s MAX aircraft from stalling by climbing too high too soon in certain conditions, the flight control computers automatically kicking in to stabilise the aircraft.
But in the two crashes, a malfunction appears to have forced the planes to nosedive. Analysts say that Boeing’s flight manual barely mentions the new system and how pilots should address it.