The software believed to be linked to the catastrophic crashes of two new Boeing 737 MAX 8 planes in less than five months is getting a makeover.
Pilots from five airlines, including the three U.S. carriers that flew the MAX jets before they were grounded worldwide, tested upgrades to the flight-control system over the weekend at Boeing’s facility outside Seattle, the aircraft manufacturer confirmed.
Boeing will also host more than 200 airline pilots, technicians and regulators in an informational session Wednesday that’s among the initial steps in its attempt to get the MAX planes back in the air.
Investigators have pointed to the stall-prevention system known as MCAS – Maneuvering Characteristics Augmentation System – as a likely factor in the Oct. 29 crash of Lion Air Flight 610, which killed all 189 aboard when it plunged into the Java Sea off the coast of Indonesia.
Aviation authorities have noted clear similarities between that airplane’s movements and the path taken by Ethiopian Airlines Flight 302, which crashed March 10 just outside the capital city of Addis Ababa and took the lives of the 157 passengers and crew on board.
Both of them exhibited drastic changes in airspeed and altitude, plummeting a few minutes after takeoff as the pilots made futile attempts to return to the airport.
On Monday, Ethiopian Airlines CEO Tewolde Gebremariam told the Wall Street Journal he believes the MCAS was activated when his company’s ill-fated flight nosedived to earth, becoming the first aviation official with inside knowledge of the accident to make such a statement.
Gebremariam told the newspaper he would wait until for the results of the ongoing investigation to make a final determination.
In a statement, Gebremariam also disputed reports that the pilots of Flight 302 – veteran captain Yared Getachew and first officer Ahmed Nur Mohammed, a relative newcomer – did not have the proper training to handle the new aspects of the MAX 8.
“Contrary to some media reports, our pilots who fly the new model were trained on all appropriate simulators,” Gebremariam said. “The crews were well trained on this aircraft.”
Boeing has been under fire for installing MCAS – a counter to the new plane’s tendency to pitch up – while providing scant information about it to the pilots and declining to offer extra training. When sensing the plane may be in danger of stalling, the software automatically lowers the nose of the aircraft to help it regain speed.
That software feature relies on readings from only one of the two angle of attack sensors on the MAX, and a faulty sensor is believed to have activated MCAS on the Lion Air flight and possibly also the Ethiopian flight even though the jets were not in danger of stalling.
A Reuters report based on the contents of the cockpit voice recorder indicated the Lion Air pilots couldn’t understand why the plane insistently lurched downward, even checking a manual in a desperate attempt to regain control.
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On Saturday, pilots from Southwest, American and United airlines as well as foreign airlines Copa and Fly Dubai took simulated flights using the MCAS in its original form and with the proposed updates, and all we able to land safely, the New York Times reported.
“We had a productive session this past Saturday and plan to reach all current and many future MAX operators and their home regulators,’’ Boeing said on its website. “At the same time, we continue to work closely with our customers and regulators on software and training updates for the 737 MAX.’’
As part of the computer upgrade to the MAX series, Boeing said it would adjust MCAS so it relies on data from two sensors, and instead of repeatedly pushing the nose down, the system would do it just once and less steeply.
In apparent response to criticism, Boeing plans to add as standard feature of the MAX a warning light that illuminates when the angle of attack sensors disagree, the Seattle Times reported, adding that previously delivered planes could have it installed at no cost. Previously, that display was optional and came with an extra charge.
The Federal Aviation Authority is expected to mandate the flight-control system upgrade by April, but getting the approval from domestic and foreign regulators for MAX planes to fly again figures to take months.
This article originally appeared on USA TODAY: MAX effort: Boeing tests changes to grounded planes to get them back in the air