The investigation continues into what caused Lion Air Flight 610 and Ethiopian Airlines Flight 302 to crash five months apart from each other, killing everyone on board. There are a couple of similarities between both incidents. The flights were operated on a Boeing 737 Max 8, a new iteration of Boeing’s iconic 737, and both crashed shortly after take off. A new report mentions that both jets were missing two safety features that Boeing only sold as options to airlines.
While the formal investigation report has not been issued for either crash, the general theory links the new MCAS system to the crashes. It’s a new safety system that Boeing developed for the plane which is to prevent a stall by automatically pushing the nose down. A detailed report has already shed light on how Boeing’s safety analysis for this feature was likely flawed.
The MCAS system takes its readings from angle of attack sensors. If it detects that the plane is pointing up at a precarious angle, it can push the plane’s nose down automatically to prevent a stall. The New York Times reports that two safety features which could have prevented the faulty reading were not present on both the Ethiopian Airlines and Lion Air jets.
The first is an angle of attack indicator which shows the readings from both sensors. The other is called a disagree light and it activates when the sensors are at odds with one another. Boeing did not offer these safety features as standard. They were sold to customers as optional extras, airlines could choose whether or not they wanted to spend money on them.
It’s also pertinent to mention here that neither safety feature was mandated by the Federal Aviation Administration. With the airline industry operating on razor thin margins as it is, many have begun to question why this was left up to the airlines which are already under pressure to maximize profitability.
“They’re critical, and cost almost nothing for the airlines to install,” said aviation analyst Bjorn Fehrm, “Boeing charges for them because it can. But they’re vital for safety.” The report mentions that Boeing is now going to make the disagree light standard on all new 737 Max planes. It continues to manufacture them even though the delivered jets have been grounded across the globe.