Boeing has admitted to knowing about a problem associated with its 737 Max 8 aircraft’s safety alert months after operators began flying the aircraft and yet failed to inform anyone about the problem. In a statement on Sunday, May 5th, Boeing added that it only informed airlines and federal regulators of the problem after the first aircraft crashed.
The safety alert in question was intended to alert pilots that a key sensor may be providing incorrect information about the aircraft’s nose pitch.
However, several months after the Max 8 made its debut in 2017, Boeing engineers realised the sensor only operated as intended if airline companies purchased an optional, additional, feature.
It was these sensors that malfunctioned during an Ocotber 2018 flight in Indonesia and again, in March, in Ethiopia. The malfunctioning software on board the aircraft forced the nose down. The pilots in both crashes were unable to regain control of the aircraft. Ultimately, some 346 people were killed in both crashes.
While it remains unclear if the warning light would have actually been able to prevent the crashes from taking place, it does raise questions of question regarding Boeing’s transparncy with regulators and customers.
Boeing reiterated that the plane was safe to fly without the sensor alert, which is called an angle-of-attack disagree light. Company representatives maintained that there were enough other gauges to inform pilots about the plane's speed, altitude, engine performance and other factors needed to fly safely.
A spokesman for the Federal Aviation Administration (FAA) said the agency was notified of the non-working warning light in November. This notification was received only after a Lion Air 737 Max crashed on October 29th in Indonesia. FAA experts determined that the non-working cockpit indicator presented a low risk.
"However, Boeing's timely or earlier communication with (airlines) would have helped to reduce or eliminate possible confusion," the spokesman said in an emailed statement. He declined to provide any additional details.
In the manuals Boeing provided to Southwest Airlines, the warning light was depicted as a standard feature just as it is on older 737s, said Southwest spokesperson Brandy King. Southwest Airlines is the biggest operator of both the Max and 737s in general.
In the aftermath of the Lion Air crash, King said Boeing representatives contacted Southwest. The manufacturer said it had discovered the lights did not work without the optional angle-of-attack indicators. As a result, Southwest began adding the optional feature too. This allowed the airline to activate the sensor-disagree warning lights on its 34 Max jets earlier this year King added. King described both features as "supplemental" and "advisory" to other information provided to pilots during flights.
The indicator was supposed to tell pilots when sensors measuring the pitch of the plane's nose appeared to conflict. This was supposed to be a sign that the sensor information was unreliable. Boeing told airlines the warning light was standard equipment on all Max jets.
But Boeing engineers quickly found out that the warning light would only operate if airlines also purchased an optional gauge that told pilots how the plane's nose was aimed in relation to the onrushing air. Boeing said the problem stemmed from software delivered to the company. A Boeing spokesman declined to name the software vendor.
In its statement on May 5th, Boeing said in-house experts had had come to the conclusion that the non-working light did not affect safety. Therefore, the company chose to fix the problem by disconnecting the alert from the optional indicators at the next planned update of cockpit display software. Boeing did not inform airlines or the FAA about this decision.
According to AP, Boeing hopes to win approval from the FAA and foreign regulators to return the Max 8 aircraft to flying duties before summer is over. When it does, the company said, the sensor warning light will be standard.
Nearly 400 Max jets were grounded across the world following the Ethiopia crash in March. Boeing is currently working to repair the software that pitched the planes' noses down based on faulty sensor readings and to provide pilots with more information about the plane's automation.