Stumo, originally from MA, is the niece of consumer activist Ralph Nader, who called for a boycott of the 737 Max on Thursday. Instead, a computer was getting erroneous readings from a sensor mounted like a weather vane on the jet's nose.
Rep. Sam Graves (R-Mo.) on the fallout from the two Boeing 737 Max plane crashes.
Boeing later acknowledged that the system had malfunctioned and apologised.
He also drew attention to the company's efforts to improve the flight control system, an effort that began after Indonesian investigators issued their preliminary report in late November. "That is extremely curious".
"Since repetitive uncommanded aircraft nose down conditions are noticed.it is recommend that the aircraft control system shall be reviewed by the manufacturer", Moges said.
"Those planes should never fly again" and consumers should boycott the jets, Nader said, speaking remotely by telephone during a press conference at the Clifford Law Offices in Chicago, where Stumo's parents also spoke.
Ethiopian Airlines CEO Tewolde GebreMariam, on his part, said he was proud of the pilots for maintaining professionalism even in such circumstances.
"We remain confident in the fundamental safety of the 737 MAX".
Ethiopian safety officials stopped short of saying the plane needs a redesign. "We are taking steps to thoroughly address this relatively minor issue and already have the solution in work to do that", Boeing told the Washington Post.
Thursday's complaint accuses Boeing of putting "profits over safety" and said the U.S. Federal Aviation Administration must also be held accountable for certifying the 737 Max. USA regulators this week demanded further improvements to a proposed fix before it could be submitted for review. To become certified to fly the Max, pilots with prior 737 experience had to do only a couple of hours of online training. Among other changes, the update will keep the safety system from kicking in when only one of the sensors detects a stall.
Manufacturers avoid halting and then resuming production as this disrupts supply chains and can cause industrial snags.
According to the report, readings from the plane's flight data recorder shows that faulty readings from a malfunctioning angle-of-attack (AOA) sensor triggered the Boeing 737 Max's Maneuvering Characteristic Augmentation System (MCAS), which is created to automatically push the nose of the plane downward.
"This accident was not survivable", said the report.
It was, he said, "apparent" that in both the Ethiopia and Indonesia flights, the software for the anti-stall system - or MCAS - was "activated in response to erroneous angle of attack information".
Boeing shares have fallen almost 10 percent since the Ethiopian Air crash. The Lion Air flight crashed last November when a faulty sensor on the plane's fuselage triggered the MCAS, sending the plane into an irreversible descent into the Java Sea, killing 189 people. Aboulafia speaks on "Bloomberg Daybreak: Australia". It " s our responsibility to eliminate this risk.
"Don't you think if Boeing knew what the fix was, we would have the fix by now?" he said.
Every plane crash typically involves multiple contributors, and the detailed Ethiopian report chronicles many factors that occurred over a matter of minutes leading to the accident. "This is territory we are going to see more of", Hart said.
However, it wasn't clear whether the Ethiopian pilots followed Boeing's recommendations to the letter. Boeing's procedures instruct pilots to leave the MCAS disconnected and continue flying manually for the rest of the flight.
But they all agreed that the speed was critical.
The preliminary report, which stops short of determining the cause of the crash, chronicles the chaotic last moments aboard the flight before it crashed.
Meanwhile, according to an initial report by Ethiopian investigators, the 737 MAX was having problems just two minutes after takeoff.
Before it picked up speed in its final dive, the plane was flying as fast as 365 knots, or 420 miles an hour - nearly twice the usual top speed at that low altitude. Nor did she or the report mention MCAS by name. Only one is used to trigger MCAS.
The Wall Street Journal reported that pilots of the Boeing 737 Max turned off a flight-control system but still couldn't get the plane to climb. The pilots fought to turn the nose of the plane up, and briefly they were able to resume climbing. He replied that it was not working. The pilots followed the "emergency checklist" but could not take back control of the aircraft, according to the report.