In a statement issued this weekend, it’s been revealed that Boeing was aware of a flaw with the AOA disagree alert on the 737 MAX prior to the crash of Lion Air Flight 610. The manufacturer says it followed its standard procedures to resolve the issue and said that the flaw didn’t compromise safety.
Boeing was aware that there was a flaw with a safety feature on the 737 MAX before both the crash of Lion Air Flight 610 and the crash of Ethiopian Airlines Flight 302, NPR reports. It has been further revealed that the manufacturer did not relate its findings on the flaw – which pertain to an issue with the angle of attack (AOA) disagree alert – to customers and safety regulators until after the crash of JT610.
The AOA disagree alert is meant to alert pilots if an aircraft’s sensors are detecting contradicting data regarding the orientation of a plane’s nose.
In a statement on the matter on Sunday, Boeing said, “In 2017, within several months after beginning 737 MAX deliveries, engineers at Boeing identified that the 737 MAX display system software did not correctly meet the AOA disagree alert requirements.”
“When the discrepancy between the requirements and the software was identified, Boeing followed its standard process for determining the appropriate resolution of such issues. That review, which involved multiple company subject matter experts, determined that the absence of the AOA disagree alert did not adversely impact airplane safety or operation,” the company went on to say.
“Accordingly, the review concluded, the existing functionality was acceptable until the alert and the indicator could be delinked in the next planned display system software update. Senior company leadership was not involved in the review and first became aware of this issue in the aftermath of the Lion Air accident,” Boeing added.
Only after the crash of JT610 did Boeing take the matter to the Federal Aviation Administration (FAA) and, as the manufacturer said, “At that time, Boeing informed the FAA that Boeing engineers had identified the software issue in 2017 and had determined per Boeing’s standard process that the issue did not adversely impact airplane safety or operation. In December 2018, Boeing convened a Safety Review Board (SRB) to consider again whether the absence of the AOA Disagree alert from certain 737 MAX flight displays presented a safety issue.”
It was decided that this did not constitute a safety risk, a point that Boeing then communicated with the FAA.
Offering final clarification, Boeing said, “Boeing is issuing a display system software update, to implement the AOA disagree alert as a standard, standalone feature before the MAX returns to service. When the MAX returns to service, all MAX production aircraft will have an activated and operable AOA disagree alert and an optional angle of attack indicator. All customers with previously delivered MAX airplanes will have the ability to activate the AOA disagree alert.”
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