Boeing announces update for 737 MAX Software

By Gokhan Ergocun

ISTANBUL (AA) - Following two air disasters months apart, Boeing on Wednesday announced an update for the Maneuvering Characteristics Augmentation System (MCAS) of 737 MAX type planes.

The update was made for providing additional layers of protection if the Angle of Attack (AOA) sensors provide erroneous data, Mike Sinnet, vice president for product development at Boeing Commercial Airplanes, said at a teleconference.

It came after many countries -- including the U.S., Turkey, Russia and Iran -- shut down their airspaces to all Boeing 737 MAX types aircraft, after two planes of the same model crashes in Ethiopia and Indonesia in less than five months.

Sinnet said MCAS, which enhances the pitch stability, is designed to activate in manual flight, with the airplane’s flaps up, at an elevated AOA.

Sinnet underlined that the MCAS software was put through hundreds of hours of analysis, laboratory testing, verification in a simulator, and it tested for in-flight certification test with Federal Aviation Administration (FAA) representatives in two flights.

"Flight control system will now compare inputs from both AOA sensors. If the sensors disagree by 5.5 degrees or more with the flaps retracted, MCAS will not activate. An indicator on the flight deck display will alert the pilots," he said.

He highlighted: "If MCAS is activated in non-normal conditions, it will only provide one input for each elevated AOA event. There are no known or envisioned failure conditions where MCAS will provide multiple inputs."

"MCAS can never command more stabilizer input than can be counteracted by the flight crew pulling back on the column. The pilots will continue to always have the ability to override MCAS and manually control the airplane," Sinnet added.

He stressed that the update eases the cabin crew's workload in non-normal flight situations.

Boeing will also add this update to the 21-day pilot training program for 737 type aircraft, he noted.

He added, after approval, the update will be accessible for all 737 MAX pilots.

On March 10, an Ethiopian Airlines Flight ET-302 crashed six minutes after takeoff from Addis Ababa Bole International Airport, killing 157 people on board.

The plane model was also involved in an October crash outside of Jakarta, Indonesia. All 189 people on board Lion Air flight JT610 were killed.