It appears that the aircraft manufacturerk knewthat the problem exists already in 2017, long before the first fatal crash involving 737 MAX 8 aircraft operated by Lion Air . The accident claimed the lives of 189 people in October 2018.
The second fatal crash followed five months later, when the Ethiopian Airlines Boeing 737 MAX 8 crashed short after take-off, killing 157 on board
No Impact on Aircraft Safety
Boeing said that among the primary features indicators and features for the safe aircraft operations are air speed, attitude, altitude, vertical speed, heading and engine power settings. At elevated angles of attack the most important features are stick shaker and the pitch limit indicator.
For this reason, after detecting the discrepancy between the requirements and the software, Boeing followed the procedures to determine how to resolve the problem, however, came to the conclusion that “the absence of the AOA Disagree alert did not adversely impact airplane safety or operation“.
The problem was set to be fixed during the following planned display system software update, without any urgent need to initiate updates right away.
Worth highlighting that Boeing said “senior company leadership was not involved in the review and first became aware of this issue in the aftermath of the Lion Air accident”.
Importance of AOA Indicator
Investigation of both crashes is still ongoing. Only preliminary reports were released and no final reasons announced, thus, there is no evidence to say that the lack of alert function contributed to fatal accidents.
Important to note that the AOA disagree alert only worked on an aircraft if the airline had purchased an additional, optional feature, known as the AOA indicator. Nevertheless, some aviation experts are convinced that if some features on the aircraft exist, it means that this data is important in any case and should not be considered as not valuable.
Source: aviationvoice.com