Prompted by the crash of a Lion Air 737 Max 8 jet in Indonesia last month, Boeing has issued a safety advisory to pilots on how to handle faulty readings from a key flight-control sensor.
“The Indonesian National Transportation Safety Committee has indicated that Lion Air Flight 610 experienced erroneous input from one of its AOA (Angle of Attack) sensors,” Boeing said in the statement. A misreading in the sensor can cause the plane to dive suddenly and confuse pilots.
All 189 people aboard Lion Air Flight 610 from Jakarta to the island of Bangka died when the plane crashed Oct. 29 just minutes after departure. Flight data shows the airplane flew erratically, just as it did on its previous three flights.
The AOA sensor provides the aircraft with a critical parameter that helps the pilots and the airplane’s software understand whether the nose is too high relative to the current of air, which can decrease airspeed and result in an aerodynamic stall.
Boeing’s safety bulletin, sent to pilots of its aircraft worldwide, provides further evidence that faulty components of the aircraft may have caused the Lion Air jet to plummet into the Java Sea.
There are already procedures in place for pilots to follow in the event of erroneous data from damaged sensors on the exterior of the aircraft, but it’s possible the Lion Air pilots didn’t have enough time to execute the procedures because the plane wasn’t able to climb more than 5,200 feet before crashing.
The Lion Air jet had three sensors feeding information to the Boeing’s flight-control software, but erroneous readings could have caused the plane’s nose to point downward in an effort to keep a flow of air under its wings.
There are currently 219 Boeing 737 Max 8 jets in operation worldwide, with an additional 4,564 on order. The model is a more fuel-efficient version of the company’s best-selling single-aisle 737 and was introduced last year, according to Reuters.