Boeing has issued an operations manual bulletin to 737 Max operators, covering air data sensors, following investigations into the crash of Lion Air flight JT610.
The manufacturer says it issued the bulletin on 6 November, directing operators to “existing flight crew procedures" to address circumstances involving erroneous angle-of-attack sensor information.
Angle-of-attack information is critical to avoiding the onset of stall conditions.
Indonesia's National Transportation Safety Committee has indicated that the ill-fated flight “experienced erroneous input" from such a sensor, says Boeing.
It stresses that issuing bulletins or recommendations, when appropriate, regarding the operation of its aircraft is a "usual process".
“The investigation into Lion Air flight 610 is ongoing and Boeing continues to co-operate fully and provide technical assistance at the request and under the direction of government authorities investigating the accident,” the manufacturer adds.
Media reports had earlier surfaced saying that Boeing was preparing to issue a service bulletin to Max operators.
The NTSC has said that it believes the crashed aircraft had been operating with airspeed indicator faults during its last four flights. It also called on Boeing and the US National Transportation Safety Board to take necessary action to prevent future cases of faulty flight system readings.
Flight JT610 had been operating from Jakarta's Soekarno-Hatta International airport to Pangkal Pinang when it crashed into the sea near the town of Karawang, claiming the lives of all 189 occupants.