FORT WORTH, Texas—The trial of a former Boeing Co. pilot, accused of misleading federal air-safety regulators before two 737 MAX jets crashed, began Friday.

Federal prosecutor Scott Armstrong told jurors that Mark Forkner, who was the 737 MAX’s chief technical pilot during its development, deceived his counterpart at the Federal Aviation Administration about engineering changes to a flight-control system known as MCAS, which was later blamed for the crashes.