Boeing has issued an operational update to 737 operators after the Lion Air crash on October 29. The Boeing statement sent to CNN said; "Boeing is providing support and technical assistance to the Indonesian National Transportation Safety Committee and other government authorities responsible for the investigation into Lion Air flight 610. 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. Whenever appropriate, Boeing, as part of its usual processes, issues bulletins or makes recommendations regarding the operation of its aircraft. On November 6, 2018, Boeing issued an Operations Manual Bulletin (OMB) directing operators to existing flight crew procedures to address circumstances where there is erroneous input from an AOA sensor. (Angle of Attack)  The investigation into Lion Air flight 610 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.” READ: Pilot on previous flight wanted to turn back. However, it is still far too early to understand what role this AOA sensor played in the tragic crash. It is understood that this is a 737 MAX problem only and there are about 200 in service. But what is a mystery is why this plane that had faults with speed /altitude sensor system on four previous flights was not pulled from service. It is not satisfactory to say that the issue was looked out checked and tested when the problem repeats itself. After two upsets the plane should have been grounded.