The jury in Texas acquitted Mark A. Forkner, a former Boeing technical pilot, of defrauding two of the company's customers.
Mr. Forkner was facing four counts of wire fraud, each carrying a maximum penalty of 20 years in prison. He was found not guilty by a jury in Fort Worth.
David Gerger, Mr. Forkner's lawyer, said in a statement that they had a great team and great client.
The federal government brought a criminal case against Boeing.
The Justice Department argued that Mr. Forkner lied to the F.A.A. about the flight control software used on the Max. Federal prosecutors said that Mr. Forkner downplayed the significance of the software to regulators to discourage them from requiring more pilot training.
The software was designed to push down the plane's nose in certain situations. Lion Air Flight 610 plummeted into the sea minutes after taking off from Jakarta, Indonesia, killing all 189 people on board. 157 people were killed in the crash of Ethiopian Airlines Flight 302.
Billions of dollars of losses and fines for Boeing were caused by the crashes and the global ban on the Max. The accidents caused a big blow to the company's reputation. The F.A.A. approved the Max for flight again in late 2020 after requiring Boeing to make changes to the plane, and most of the rest of the world followed suit.
The Justice Department argued that Mr. Forkner discovered in 2016 that MCAS could be activated in broader conditions than initially thought. He urged the F.A.A. to not mention MCAS in its pilot training guidance for the Max because he failed to alert federal officials of that fact.
The trial was described by Mr. Gerger as a search for a scapegoat.
Boeing agreed to pay billions of dollars in financial compensation to airlines in a settlement with the Justice Department. The families of more than a dozen crash victims recently criticized that deal and said federal officials had left them in the dark before it was announced. They want to take away protection from Boeing from further criminal prosecution.
Boeing has struggled to move past other troubles despite the fact that the Max has been back in service for more than a year. The company is working with the F.A.A to address quality concerns and has paused deliveries and slowed production of the 787.
A high-profile engine failure aboard a Boeing 777 over Colorado raised concerns about that plane before attention shifted to the manufacturer of the engine. On Monday, a Boeing plane plunged from the sky, killing 130 people.