This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

DALLAS (AP) — A former Boeing pilot was indicted Thursday by a federal grand jury on charges of deceiving safety regulators about the 737 Max jetliner, which was later involved in two deadly crashes.

The indictment charges Mark A. Forkner with giving the Federal Aviation Administration false and incomplete information about an automated flight-control system that played a role in the crashes, which killed 346 people.

Prosecutors said that because of Forkner’s alleged deception, the system was not mentioned in pilot manuals or training materials.

An attorney for Forkner did not immediately respond for comment. Boeing and the FAA declined to comment.

Forkner, 49, was charged with two counts of fraud involving aircraft parts in interstate commerce and four counts of wire fraud. Federal prosecutors said he is expected to make his first appearance in court on Friday in Fort Worth, Texas. If convicted on all counts, he could face a sentence of up to 100 years in prison.

The indictment charges that he hid information about a flight-control system that activated erroneously and pushed down the noses of Max jets that crashed in 2018 in Indonesia, and 2019 in Ethiopia. The pilots tried unsuccessfully to regain control, but both planes went into nosedives minutes after taking off.

Forkner was Boeing’s chief technical pilot on the Max program. Prosecutors said that Forkner learned about an important change to the Maneuvering Characteristics Augmentation System flight-control system in 2016, but withheld the information from the FAA. That led the agency to delete reference to MCAS from a technical report and, in turn, it didn’t appear in pilot manuals. Most pilots didn’t know about MCAS until after the first crash.

Prosecutors suggested that Forkner downplayed the power of the system to avoid a requirement that pilots undergo extensive and expensive retraining, which would increase training costs for airlines. Congressional investigators suggested additional training would have added $1 million to the price of each plane.

“In an attempt to save Boeing money, Forkner allegedly withheld critical information from regulators,” said Chad Meacham, acting U.S. attorney for the northern district of Texas. “His callous choice to mislead the FAA hampered the agency’s ability to protect the flying public and left pilots in the lurch, lacking information about certain 737 MAX flight controls.”

Forkner told another Boeing employee in 2016 that MCAS was “egregious” and “running rampant” when he tested it in a flight simulator, but he didn’t tell that to the FAA.

“So I basically lied to the regulators (unknowingly),” Forkner wrote in a message that became public in 2019.

Forkner, who lives in a Fort Worth suburb, joined Southwest Airlines after leaving Boeing, but left the airline about a year ago.

Chicago-based Boeing agreed to a $2.5 billion settlement to end a Justice Department investigation into the company’s actions. The government agreed to drop a criminal charge of conspiracy against Boeing after three years if the company carries out terms of the January 2020 settlement. The settlement included a $243.6 million fine, nearly $1.8 billion for airlines that bought the plane and $500 million for a fund to compensate families of the passengers who were killed.

Dozens of families of passengers are suing Boeing in federal court in Chicago.

Crash investigations highlighted the role of MCAS but also pointed to mistakes by the airlines and pilots. Max jets were grounded worldwide for more than a year and a half. The FAA approved the plane for flying again late last year after Boeing made changes to MCAS.