For Boeing and other aircraft manufacturers, the practice of charging to upgrade a standard plane can be lucrative. Top airlines around the world must pay handsomely to have the jets they order fitted with customized add-ons.
Sometimes these optional features involve aesthetics or comfort, like premium seating, fancy lighting or extra bathrooms. But other features involve communication, navigation or safety systems, and are more fundamental to the plane’s operations.
Many airlines, especially low-cost carriers like Indonesia’s Lion Air, have opted not to buy them — and regulators don’t require them. Now, in the wake of the two deadly crashes involving the same jet model, Boeing will make one of those safety features standard as part of a fix to get the planes in the air again.
… Boeing’s optional safety features, in part, could have helped the pilots detect any erroneous readings. One of the optional upgrades, the angle of attack indicator, displays the readings of the two sensors. The other, called a disagree light, is activated if those sensors are at odds with one another.
Boeing will soon update the MCAS software, and will also make the disagree light standard on all new 737 Max planes, according to a person familiar with the changes, who spoke on condition of anonymity because they have not been made public. The angle of attack indicator will remain an option that airlines can buy.