Boeing will make standard on its troubled new airliner a safety feature that might have helped the crew of a jet that crashed shortly after takeoff last year in Indonesia, killing everyone on board.
The equipment, which had been offered as an option, alerts pilots of faulty information from key sensors. It will now be included on every 737 Max as part of changes that Boeing is rushing to complete on the jets by early next week, according to two people familiar with the changes.
The sensors measure whether the plane is pointed up, down or level in relation to the direction of onrushing air. Software on the Max can push the plane’s nose down if data from one of the sensors indicates the plane is tilted up so sharply that it could stall and fall from the sky.
In the Lion Air case, the sensors malfunctioned and gave wildly conflicting information, and the plane crashed minutes after takeoff. A preliminary report described a grim fight by the pilots to control the plane as it pitched downward more than two dozen times.
It is not known whether the same flight-control system played a role in the March 10 crash of the Ethiopian Airlines jet shortly after takeoff from Addis Ababa, but regulators say both planes had similar erratic flight paths, an important part of their decision to ground the roughly 370 Max planes around the world.
The Lion Air plane also lacked another optional feature: gauges or displays that would let pilots see at a glance the up-or-down direction of the plane’s nose. It was unclear whether such “angle of attack” or AOA gauges will also become standard equipment on the Max.
Boeing declined to say why the options were not standard equipment sooner.
Max jets flown by Lion Air and Ethiopian Airlines lacked both the sensor-disagreement warning and AOA gauges, according to the New York Times, which first reported Boeing’s decision to make the warning standard. Boeing declined to comment on details of customer orders.
The average list price for a 737 Max 8 is $121.6 million, according the company’s website, although airlines routinely receive deep discounts. Boeing charges extra for additional features but won’t discuss those numbers, calling it valuable proprietary information.
Low-cost carriers such as Indonesia’s Lion Air may be more likely than the larger airlines to turn down options to save money.