Boeing's Mark Forkner pilot in 2016 sent a message about the control error of the 737 MAX, but they were only made public on October 18.

According to internal messages between Boeing employees, Forkner, the former chief technical pilot of the 737 MAX aircraft, said the Flight Control Enhancement System (MCAS) had problems testing. This system is involved in two plane crashes in Indonesia and Ethiopia, killing a total of 346 people.

In messages exchanged in November 2016, Forkner said that the MCAS system in the cockpit was "very difficult to control". "I tried to keep the plane balanced at 1,200 m at a speed of 426 km / h, but the plane drove its nose madly," said Forkner.

The test pilot told his colleague that he had "essentially deceived the regulator" about the flight simulator experience, but his Boeing colleague quickly rejected it. "That's not a lie, nobody told us about this case."

In emails sent to the US Federal Aviation Administration (FAA) in March 2016, Forkner wrote that it was unnecessary to mention the MCAS system in the pilot's manual for pilots because MCAS is computer-controlled, Works explicitly and is designed to activate in very rare situations.

Pilots who used the 737 MAX later complained they were not notified of the presence of MCAS on board until the Lion Air crash in Indonesia.

The Federal Aviation Administration (FAA) yesterday asked Boeing CEO Dennis Muilenburg to "immediately" explain the delay in "related" material delivery that Boeing had discovered a few months ago.

"These messages show that Boeing has kept the damaging information confidential to FAA, which is very worrying," Peter DeFazio, chairman of the US House of Transportation Committee, wrote in a letter to the Secretary of State. US Elaine Chao information on 18/10. The FAA said it "is reviewing the information to take appropriate action".

Boeing said on October 18 that Muilenburg called FAA Administrator Steve Dickson to respond to the due diligence request and to ensure that the company "is taking every action possible to return the 737 MAX to safety." ".

The company said it passed documents containing messages from former Boeing employees to the investigating agency earlier this year. Boeing has cooperated in the investigation of the 737 MAX line of the House Transportation and Infrastructure Committee and will continue to do so in US government investigations, the company added.

Federal prosecutors supported by the FBI, the Inspector General of the Department of Transportation, the US Senate Trade Commission and a number of investigators have confirmed will ask questions to Muilenburg at the 29th hearing. /ten.

Boeing is facing the worst crisis in history, after two consecutive crashes by Ethiopian Airlines in March and Lion Air in Indonesia five months earlier. The two accidents are all related to the MCAS system, making the 737 MAX series banned from flying around the world for more than 7 months. Boeing said it suffered at least $ 8 billion in damage from the crisis.