The previously undisclosed detail on the earlier Lion Air flight represents a new clue in the mystery of how some 737 Max pilots faced with the malfunction have been able to avert disaster while the others lost control of their planes and crashed.
According to a report from Bloomberg, the "dead head" pilot was riding in the cockpit of the same aircraft involved in the deadly crash. The data was back in Addis Ababa on Tuesday, sources familiar with the probe told Reuters.
Additionally, the Indonesia safety committee report said the plane had had multiple failures on previous flights and hadn't been properly repaired.
As the captain worked to keep the plane in the air, the jet's computer incorrectly sensed a stall and kept trying to push the plane's nose down.
New investigations are starting into the certification of the Boeing 737 Max 8 after two fatal crashes in less than six months.
The captain, 31, was at the controls of Lion Air Flight JT610 when the almost new jet took off from Jakarta.
The FAA said Wednesday it will review the information from the cockpit voice recorder and the flight data recorder from the Ethiopian Airlines accident as it becomes available.
MCAS is activated when angle of attack (AOA) sensors indicate that the airframe is in a dangerously high angle and attempts to correct it by pushing the plane nose down. This week, the company named the chief engineer of its commercial airplanes division to lead the company's role in the investigations into the October 29 crash of the Lion Air jet and the March 10 Ethiopian Airlines crash.
The FAA expects to certify Boeing's modifications and plans for pilot training in April or May, one of the people said. When flight testing revealed an issue with meeting the certification standards, they developed a fix, Maneuvering Characteristics Augmentation System (MCAS), but did not tell airline pilots about it.
As the 31-year-old captain tried in vain to find the right procedure in the handbook, the 41-year-old first officer was unable to control the plane, two of the sources said.
The Indian-born captain was silent at the end, while the Indonesian first officer said "Allahu Akbar", or "God is greatest", a common Arabic phrase in the majority-Muslim country that is used to express excitement, shock, praise or distress.
FILE PHOTO: Men unload a case containing the black boxes from the crashed Ethiopian Airlines Boeing 737 MAX 8 outside the headquarters of France's BEA air accident investigation agency in Le Bourget, north of Paris, France, March 14, 2019.
Representatives of the Justice Department, the FBI and Transportation Department declined to comment, saying they could neither confirm nor deny an investigation.
"Boeing, in developing the 737 Max 8, obviously felt intense competitive pressure to get the new aircraft to market as quickly as possible".
FAA spokesman Greg Martin would not comment on whether the agency's reputation has been hurt by its approval of the Max, the crashes or the agency's initial hesitation to ground the planes after the second crash.
The investigation expanded to include the January 2000 crash of Alaska Flight 261 that killed 88 people, which the National Transportation Safety Board later blamed on the airline's faulty maintenance practices and poor FAA oversight.