Boeing Co. is advising airlines on procedures to deal with false readings from a plane sensor that authorities say malfunctioned on a 737 Max jet that crashed off the Indonesian coast over a week ago. The operations-manual bulletin was issued Tuesday; Boeing said in a statement posted to Twitter, and tells crew to use existing guidelines when dealing with erroneous inputs from the so-called angle of attack sensor. That sensor is intended to maintain air flow over a plane’s wings but if it malfunctions can lead to an aerodynamic stall – which can cause aircraft to abruptly dive.
It was earlier reported that Boeing was said to be preparing to issue an alert to operators of the 737 Max jet in response to the investigation into the Oct. 29 crash of the Lion Air plane, which saw 189 people killed.
Under some circumstances, such as when pilots are flying manually, the Max jets will automatically try to push down the nose if they detect that an aerodynamic stall is possible, the person said. One of the critical ways a plane determines if a stall is imminent is the angle of attack measurement.
The probe into what happened with the Lion Air plane “is ongoing and Boeing continues to cooperate fully and provide technical assistance at the request and under the direction of government authorities investigating the accident,” the company said in its statement.
On Nov. 5, the Indonesian transportation-safety committee called on Boeing and the U.S. National Transportation and Safety Board “to take necessary steps to prevent similar incidents, especially on the Boeing 737 Max, which number 200 aircraft all over the world,” according to a statement.
Boeing has delivered 219 Max planes – the latest and most advanced 737 jets – since the new models made their commercial debut last year with a Lion Air subsidiary. Boeing has more than 4,500 orders for the airliners, which feature larger engines, more aerodynamic wings and an upgraded cockpit with larger glass displays. The single-aisle family is Boeing’s biggest source of profit.