Boeing has said a software update to prevent erroneous data from triggering an anti-stall system, which is under scrutiny after the deadly nose-down crashes, would be submitted in the coming weeks.
The FAA said the group "will conduct a comprehensive review of the certification of the automated flight control system on the Boeing 737 Max aircraft" and "evaluate aspects of the 737 Max automated flight control system, including its design and pilots' interaction with the system, to determine its compliance with all applicable regulations and to identify future enhancements that might be needed".
The so-called MCAS software is at the centre of accident probes in both the crash of Ethiopian flight 302 and a Lion Air accident in Indonesia five months earlier that together killed 346 people.
That's significant because the sensor is suspected of sending faulty signals to a flight control system created to force the nose of the plane down to prevent a stall.
Although Boeing is developing a fix to its MCAS software, the US Federal Aviation Administration (FAA) has expressed confidence in MCAS. She added that an worldwide team investigating the crash includes the National Transportation Safety Board and the Federal Aviation Administration in the U.S., France's BEA and the European Union Aviation Safety Agency.
The FAA said in a statement that it is continuing to work toward a full understanding of what happened and will take appropriate action as findings become available.
Both planes had an automated system that pushed the nose down when sensor readings detected the danger of an aerodynamic stall, but it now appears that sensors malfunctioned on both planes. Incorrectly sensing a stall, the aircraft's system tried to force the nose down four separate times during the flight, in the end overpowering the flight crew's ability to keep the airplane climbing. The FAA has said it will review the software before allowing the Max to fly again.
Ethiopian investigators did not address that issue at Thursday's news conference, saying only that the pilots had done what they were supposed to. The report from Ethiopia's Aircraft Accident Investigation Bureau said the sensor problems began about a minute after the plane was cleared for takeoff.
"I'd like to reiterate our deepest sympathies are with the families and loved ones of those who lost their lives in the accident", said Boeing Commercial Airplanes President and CEO Kevin McAllister.
Following the Lion Air crash last October, Boeing issued an Operations Manual Bulletin advising airlines how to deal with "erroneous input from an AOA sensor".
"What is special about this case is that two crashes seem to have a very, very similar reason".
The subpoena to Lemme, details of which emerged Tuesday, indicates the broad scope of theJustice Department investigation into what caused the two 737 MAX crashes, requesting, "Any and all documents, records, emails, correspondence, audio or video recordings, text messages, voice messages, chats, and/or other communications, including drafts, related to the Boeing 737 Max".
"If pilots sit there and follow the rules that have been given to them by the manufacturer, then they should be able to rely on the fact that they are correct", Hasse said.
Turning the wheel is slower than the electric motors, so the pilots could have turned MCAS back on in hopes of using the electric motors to quickly point the nose up, he theorized. The later they shut it off, the less time they had to recover, he said.