Boeing CEO defends 737 MAX flight control software as the doubts to raise on the plane's certification process

Chicago - Boeing chief executive Dennis Muilenburg met reporters and shareholders on April 29 at the annual shareholders meeting of the company in Chicago.

At a 15-minute media briefing after the shareholder meeting, Muilenburg refused to admit that the anti-stall software of the MAX jets was faulty and said Boeing followed appropriate protocols during the design process.

Muilenburg said that Boeing was making progress to return the grounded 737 MAX jets to the service. Preliminary reports of the Lion Air and Ethiopian incidents had pointed the new anti-stall software of the aircraft as the cause of the two fatal crashes.

During the meeting, Boeing's chief executive defended the anti-stall system which was exclusively designed for the 737 MAX jets of the manufacturer.

"We've confirmed that it was designed for our standards, certified for our standards and we're confident in that process," Muilenburg said.

"It operated according to those design and certification standards. We haven't seen a technical slip or gap," Boeing's CEO added.

Muilenburg said the erroneous angle of attack (AOA) data was a common link in a series of events that caused both aircraft to crash.

"The update will make the aircraft safer going forward, I'm confident with that change it will be one of the safest airplanes ever to fly," he added.

Muilenburg also said that the Lion Air and Ethiopian pilots did not completely follow the procedures that Boeing had outlined in its training manuals in case of a malfunction in the MCAS system.

The preliminary report of the Ethiopian Flight 302 crash says the pilots switched off the electrical system connecting MCAS to the horizontal stabilizer as it was stated in the technical manuals, but they couldn't be able to regain the control of the aircraft.

Boeing has been working on a fix for the anti-stall system of the aircraft known as MCAS. The company plans to present the updated software to the civil aviation regulators and airline operators after the U.S. Federal Aviation Agency approves the changes.

The manufacturer has also designed computer-based training for pilots about the procedures to be followed in similar cases.