Doomed Boeing Jets Lacked 2 Safety Features That Company Sold Only as Extras


As the pilots of the doomed Boeing jets in Ethiopia and Indonesia fought to regulate their planes, they lacked two notable security options of their cockpits.

One cause: Boeing charged additional for them.

For Boeing and different plane producers, the apply of charging to improve an ordinary aircraft might be profitable. Top airways around the globe should pay handsomely to have the jets they order fitted with personalized add-ons.

Sometimes these non-obligatory options contain aesthetics or consolation, like premium seating, fancy lighting or additional bogs. But different options contain communication, navigation or security programs, and are extra elementary to the aircraft’s operations.

Many airways, particularly low-cost carriers like Indonesia’s Lion Air, have opted to not purchase them — and regulators don’t require them.

Now, within the wake of the 2 lethal crashes involving the identical jet mannequin, Boeing will make a type of security options commonplace as a part of a repair to get the planes within the air once more.

It will not be but identified what induced the crashes of Ethiopian Airlines Flight 302 on March 10 and Lion Air Flight 610 5 months earlier, each after erratic takeoffs. But investigators are whether or not a brand new software program system added to keep away from stalls in Boeing’s 737 Max collection could have been partly accountable. Faulty knowledge from sensors on the Lion Air aircraft could have induced the system, identified as MCAS, to malfunction, authorities investigating that crash suspect.

Federal prosecutors are investigating the event of the Boeing 737 Max jet, in response to an individual briefed on the matter. As a part of the federal investigation, the F.B.I. can also be supporting the Department of Transportation’s inspector common in its inquiry, stated one other particular person with information of the matter.

The Justice Department stated that it doesn’t verify or deny the existence of any investigations. Boeing declined to touch upon the inquiry.

The jet’s software program system takes readings from certainly one of two vanelike gadgets referred to as angle of assault sensors that decide how a lot the aircraft’s nostril is pointing up or down relative to oncoming air. When MCAS detects that the aircraft is pointing up at a harmful angle, it may possibly routinely push down the nostril of the aircraft in an effort to stop the aircraft from stalling.

The three American airlines that bought the 737 Max each took a different approach to outfitting the cockpits.

American Airlines, which ordered 100 of the planes and has 24 in its fleet, bought both the angle of attack indicator and the disagree light, the company said.

Southwest Airlines, which ordered 280 of the planes and counts 36 in its fleet so far, had already purchased the disagree alert option, and it also installed an angle of attack indicator in a display mounted above the pilots’ heads. After the Lion Air crash, Southwest said it would modify its 737 Max fleet to place the angle of attack indicator on the pilots’ main computer screens.

United Airlines, which ordered 137 of the planes and has received 14, did not select the indicators or the disagree light. A United spokesman said the airline does not include the features because its pilots use other data to fly the plane.

Boeing is making other changes to the MCAS software.

When it was rolled out, MCAS took readings from only one sensor on any given flight, leaving the system vulnerable to a single point of failure. One theory in the Lion Air crash is that MCAS was receiving faulty data from one of the sensors, prompting an unrecoverable nose dive.

In the software update that Boeing says is coming soon, MCAS will be modified to take readings from both sensors. If there is a meaningful disagreement between the readings, MCAS will be disabled.

Incorporating the disagree light and the angle of attack indicators on all planes would be a welcome move, safety experts said, and would alert pilots — as well as maintenance staff who service a plane after a problematic flight — to issues with the sensors.

The alert, especially, would bring attention to a sensor malfunction, and warn pilots they should prepare to shut down the MCAS if it activated erroneously, said Peter Lemme, an avionics and satellite-communications consultant and former Boeing flight controls engineer.

“In the heat of the moment, it certainly would help,” he said.



Source link Nytimes.com

Get more stuff like this

Subscribe to our mailing list and get interesting stuff and updates to your email inbox.

Leave a Reply

Your email address will not be published. Required fields are marked *

Get more stuff like this
in your inbox

Subscribe to our mailing list and get interesting stuff and updates to your email inbox.