The Federal Aviation Administration discovered another potential risk in Boeing’s 737 Max 8 jets, which were grounded in the U.S. and abroad in March after 346 people died in two separate crashes involving the plane.
Reuters first reported the potential risk, which Boeing will now need to address, on Wednesday. The issue was found during a simulator test performed last week, according to the news agency, and is believed to be different from the flaws that investigators linked to the crashes earlier this year.
Details of the specific risk were not made clear in Reuters’ report, though CNN said a risk had been discovered in the computer system that could push the plane’s nose down, citing sources familiar with the testing.
The FAA confirmed later Wednesday that it had found another potential risk in the 737 Max 8 jets.
The FAA said that an independent review panel, the Technical Advisory Board, was reviewing the agency’s ongoing work on restoring the 737 Max 8’s service.
“On the most recent issue, the FAA’s process is designed to discover and highlight risks,” the FAA said.
The agency said Boeing would have to “mitigate” the new risk.
Boeing is under severe scrutiny after one of its 737 Max 8 aircraft crashed in Indonesia and another crashed in Ethiopia five months later, both times killing everyone on board. A malfunctioning anti-stall system and a design flaw in the aircraft’s flight simulator software is believed to be linked to both of the crashes.
In May, The New York Times reported that Boeing had discovered that its flight simulators could not replicate the conditions that occur when the anti-stall system malfunctions, giving pilots a false impression of how much force they would need to employ to regain control of the jet once the anti-stall system was activated.
The pilots who died in the 737 Max 8 crashes struggled to disengage the planes’ automated anti-stall software and failed to regain control of the aircraft as the anti-stall system repeatedly pushed the aircraft’s nose downward.
Following the lead of countries around the world, President Donald Trump issued an emergency order grounding all 737 Max 8 planes in the U.S. in response to the deadly crashes.
Boeing officials acknowledged there were design flaws in the simulation software in May. Last week, the company’s CEO Dennis Muilenburg also admitted that Boeing made a “mistake” by failing to tell regulators that a safety indicator in the cockpit of the Max jet didn’t work properly.
When speaking to reporters in Paris last week, Muilenburg expressed confidence that the jets would be cleared to fly later this year, according to The Associated Press.
But the FAA on Wednesday said it was not following a “prescribed timeline” to bring the jets into service.
“The [FAA] is following a thorough process, not a prescribed timeline, for returning the Boeing 737 MAX to passenger service,” the agency said. “The FAA will lift the aircraft’s prohibition order when we deem it is safe to do so.”