The Boeing 737 MAX crashed in Indonesia had 40 seconds to cancel the faulty system at the origin of the tragedy.

A group of badysts investigating the two recent tragedies involving a Boeing 737 MAX revealed that the pilots had barely 40 seconds to cancel the automated system that caused the aircraft collapse, according to the newspaper The New York Times.

It has long been suspected that MCAS, software that controls the nose tilt of the aircraft to prevent loss of lift, had worked in error on the flights of Lion Air and Ethiopian Airlines that had fallen in October and March, causing the death of 346 people.

Boeing, the US automaker that is now under review, said it was possible to cancel this automatic process and regain full control of the aircraft, highlighting the lack of expertise of the crews involved, butDifferent tests on simulators show that the complicated process of disabling the system and correcting the tilt of the nose over time must be done in 40 seconds or less to avoid a disaster, indicated two persons participating in the surveys.

Even the test pilots who suffered in the simulator conditions similar to those of the two tragic thefts They said they were surprised by the enormous power the MCAS has over the 737 MAX.

The Increasing Maneuver Characteristics System function is to correct the nose tilt of the aircraft, or its angle of attack, avoid the "stall", the moment when the aircraft reaches a speed lower than the minimum and loses the lift, then fall as if it was a stone.

In this way, when the instruments signal that the device goes up too much, it loses speed quickly, the MCAS intervenes and automatically corrects without the driver's knowledge, by changes in the position of the lifts (the small wings in the tail of the plane).

It is thought that in the case of Lion Air flight 610 An error in the angle, attack, speed and altitude sensors provided the MCAS with incorrect information, which led to the belief that the system was stuck.. In this way, the aircraft automatically entered a dive that the pilots could not reverse.

They did not know what was going on either, since information and training on MCAS and its cancellation are very rare.

Something similar would have happened with Ethiopian Airlines Flight 302, which fell to the ground in Ethiopia shortly after takeoff, as did Flight 610 in Indonesia.

Although Boeing and the US Federal Aviation Administration (FAA) reacted slowly to the second tragedy in Ethiopia, be the last to consent to a flight ban for all 737 MAXs for future review, which airlines and some countries had already put in place, andThe manufacturer has announced a software update to resolve the problem and facilitate the MCAS cancellation process.

Currently, This procedure is not simple, but it is not impossible to achieve. If the pilot notices that the nose of the plane is falling, he can reverse it by pressing a button located on the control lever. But even if it cancels the last movement of the MCAS, it does not turn off the system, I could try again to interfere.

To avoid this, the pilot must follow two other steps:Connect the power supply to the motor that allows the MCAS to move the elevators and use a small wheel to correct the position.

In the simulations, it has been proved that all this procedure can be performed successfully in less than 40 seconds thus avoiding a tragedy. But the truth is that this was done with a much better understanding of the functioning of MCAS, in the hope that the failure would occur and likely after several trials.

The situation is very different in the air, with 200 people on board, without waiting for such failures and without proper training from the manufacturer and the airline on how to fix it.

For example, in the case of the Lion Air flight, thethe pilots used the joystick knob at least 12 times to reverse the small falls of the nose. But every time the MCAS system, He continued to receive inaccurate readings from the sensors and again tried to lower his nose.

But neither the commander nor the co-pilot knew of the existence of the MCAS, and used the button without knowing why the nose was falling again, much less how to unplug the electricity.

After the accident in Indonesia and before that in Ethiopia, Boeing sent to all its customers a bulletin explaining the procedure to follow in case of MCAS error.

But before that, the manufacturer and the FAA had agreed that the pilots did not need to know the new system, as this would generate more work and too much information before a task, the flight already too demanding.

The tragedy in Ethiopia has shown that Boeing's newsletter and efforts to make the process public were not enough. For this reason, the company is making a series of changes to the system, implementing various safeguards that must be approved by the FAA.

The most important is perhaps the requirement that the MCAS receive information on the theft of two identical sensors, and not just one as it has been until now. In this way, if the two sensors report different data, the system would be automatically canceled.

The Boeing 737 MAX comes from the factory with these two sensors as a safety measure, so many people criticized the decision that the system was only system-based, which was a serious design error.

But also the number of MCAS interventions on one will be limited, and I knowwill identify when the system will want to take the nose in one direction and the joystick will try to do it in the opposite direction, also canceling the process.