Why researchers think the two Boeing 737 crashed for similar reasons – 14/03/2019

On the basis of new satellite tracking data, US and Canadian regulators said Wednesday that there were similarities between the two Boeing 737 Max plane crashes: the one that crashed Sunday in Ethiopia, killing 157 peopleand that of the airline Lion Air which killed 189 people in Indonesia last October.

As published in New York Timesthe causes of these two accidents are under investigation. But preliminary indications show that the two planes could have been shot for the same reason: the automatic malfunction of the system called MCAS.

Clarin Bulletins

What happened today? We tell you the most important news of the day and what will happen tomorrow when you get up

Monday to Friday afternoon.

Canada's Transport Minister Marc Garneau says satellite tracking data revealed "vertical variations" on the flight of Ethiopian Airlines which reminds the sights before the accident of Indonesia in October.

The experts compared the profile of the two flights and found "parallels" in their trajectories and "variations" that "exceed a threshold of similarity with regard to the possible causes of the accident in Ethiopia". Although this is "inconclusive", it is "a sufficient similarity to cross the precautionary threshold," the minister said.

Look also

Garneau added that the new automatic control system for these aircraft, MCASI could have had a role. The MCAS was designed specifically for the 737 MAX, whose engines are heavier than the previous generation 737.

The complete data cited by the authorities have not yet been made public. Many experts do not rule out other possibilities, such as a driver error or other failing system.

But aviation experts believe that the MCAS could have been activated on the flight from Ethiopia and could have contributed to the accident. And many scholars believe that during the tragedy of October, Indonesian pilots lost the battle against the MCAS.

Perhaps because of erroneous sensor readings, the automatic system has pushed the nose of the Indonesian aircraft. The pilots countered and again looked up, but they were canceled by the system. Each interval took about 15 to 20 seconds. This led to a series of variations of altitude until the pilots were crushed.

Public data on the Ethiopian flight are less clear and complete, but they seem to show the same model.

Look also

"The oscillation of about 15 to 20 seconds it's a tell-tale sign of the possible involvement of the MCAS system, "said John Hansman, professor of aeronautics at the Mbadachusetts Institute of Technology.

He added that planes such as the Boeing 737 oscillated naturally due to turbulence and other effects. But these changes have different durations: between five and eight seconds, or a minute or more. Variations in the intervening interval of 15 seconds or more do not have an obvious explanation, he said.

"Based on the available data, there are similarities between the Lion Air cases (in Indonesia) and this case (Ethiopia) in terms of the 15-second periodicity.This would indicate a similar phenomenon.We will know more when we have a recorder of flight data, "concluded Professor Hansman.

PS