Flight data has already indicated some similarities with a crash by the same model of plane during a Lion Air flight in October.
In the week ending March 15, Boeing shares sank 10.3 percent, despite a 1.5 percent gain on Friday after the Chicago-based aircraft maker said it may be done faster than expected with the software upgrade for its 737 Max aircraft. The disaster led to the worldwide grounding of the Boeing 737 MAX 8 aircraft, the plane that crashed.
Ethiopian Airlines says its pilots received special training on how to deal with the Max's anti-stall software.
The French agency said that, in addition to Boeing, teams were also attending from the U.S. National Transportation Safety Board, Federal Aviation Administration and the European Union Aviation Safety Agency. The victims of the crash came from 35 countries.
"If there were to be anything defective in terms of the plane or any of its components, then it would be possible to bring a claim against the manufacturer as well as the airline", the head of law firm Irwin Mitchell's travel litigation group, Clive Garner, said.
France's Bureau of Inquiry and Analysis for Civil Aviation Safety has confirmed that it took possession of the flight data and cockpit voice recorders on Thursday.
Boeing and US air safety regulators have been at odds over how much pilot training will be required along with the software fix, the Wall Street Journal reported on Friday. Engineers are making changes to the system created to prevent an aerodynamic stall if sensors detect that the jet's nose is pointed too high and its speed is too slow. Both crews tried to return to the airport.
The 737, which first entered service in the late 1960s, is the aviation industry's best-selling model and Boeing's top earner. Investigators examining that crash are looking at whether software created to prevent a stall might have automatically pushed the plane's nose down repeatedly.
At the rural crash site outside Addis Ababa, searchers picked through the debris.
In Ethiopia, officials have begun delivering bags of earth to family members of the 157 victims of the crash instead of the remains of their loved ones because the identification process is going to take such a long time. Including, Nine Ethiopians, 32 Kenyans, 18 Canadians and eight people each from China and Italy.
Associated Press writers Dave Koenig in Houston and Tom Krisher in Detroit contributed.