U.S. top aircraft manufacturer Boeing Company has issued an Operations Manual Bulletin to 737 Max operators after Indonesian Lion Air Flight 610 crashed into the Java Sea last month, killing all 189 people aboard.

Boeing said in a statement released late Tuesday that it is providing support and technical assistance to the Indonesian National Transportation Safety Committee in the probe of the air crash involving a Boeing 737 Max jet that was delivered to Lion Air less than three months ago.

The manual bulletin directs 737 Max operators to "existing flight crew procedures" to address circumstances involving erroneous angle-of-attack (AOA) sensor information.

The AOA sensor is a vane installed outside of the aircraft to give pilots a visual reading of the plane's angle between the oncoming air or relative wind and a reference line on the airplane or wing. The AOA information is critical to avoiding the onset of stall conditions.

"Whenever appropriate, Boeing, as part of its usual processes, issues bulletins or makes recommendations regarding the operation of its aircraft," Boeing said.

It added that the investigation into Lion Air flight 610 is ongoing and the company continues to cooperate fully and provide technical assistance at the request of government authorities investigating the accident.

Flight JT610 was flying from Soekarno-Hatta International airport in Jakarta, capital of Indonesia, to Pangkal Pinang, the largest city on the country's Bangka Belitung Islands, when it crashed into the sea near the town of Karawang, about 51 km east of Jakarta.

Currently, more than 200 Boeing 737 Max airplanes are in service around the world.