The two Boeing that fell were missing two key security measures

NEW YORK.- While the pilots of the plane from

Boeing

737 MAX 8 of Ethiopian Airlines and the Indonesian Lion Air struggled to control their planes, lacking two important safety measures in their cabins. One reason: Boeing bills them an extra fee.

For Boeing and other aircraft manufacturers, billing for a standard airplane upgrade can be lucrative. Major airlines around the world must generously pay for the jets they order to be adjusted with custom add-ons.

Sometimes these optional features involve aesthetics or comfort, such as premium seats, stylish lighting or extra bathrooms. But other features involve communication, navigation or safety systems, and are more fundamental to flight operations.

Many airlines, especially low-cost airlines such as Lion Air, have chosen not to buy them and regulators do not need them.

Now, after two fatal accidents involving the same model aircraft, Boeing will make standard one of these safety features as part of the solution allowing planes to fly again.

It is unclear what caused the crash of Ethiopian Airlines Flight 302 on March 10 and Lion Air Flight 610 five months earlier, both after irregular take-offs. But researchers are badyzing whether a new software system has been added to avoid so-called losses (
stalls) in the 737 series, Max de Boeing may be partly responsible for the tragedy.

The erroneous data from the aircraft's Lion Air sensors could have caused the malfunction of the system, called MCAS, by authorities who investigated the suspect's accident.

This software system takes measurements from two rod-shaped devices, called angle-attack sensors, that determine the direction in which the nose of the aircraft points upward or downward. low compared to the approaching air. When the MCAS detects that the aircraft is facing a dangerous angle, it can automatically lower the nose of the aircraft to prevent the aircraft from coming to a stop.

Boeing's optional security features may have helped pilots detect erroneous readings. One of the optional updates, the angle of attack indicator, indicates the readings of the two sensors. The other, called detuning light, is activated if these sensors disagree with each other.

Boeing will soon update the MCAS software and will also shed light on the disagreement on all new 737 Max devices, according to a person familiar with the changes, who spoke under cover of anonymity as they did not been made public. The angle of attack indicator will remain an option that airlines can buy.

The New York Times