Boeing CEO Dennis Muilenburg said the company made a “mistake” in how it handled a problematic cockpit warning system in its 737 Max jets that led to two crashes, and killed 346 people. The Federal Aviation Administration faulted Boeing for not alerting regulators for more than year that an automated stall-prevention system on the Boeing 737 MAX 8 and MAX 9 models had issues. Muilenburg told reporters that Boeing’s communication with regulators, customers, and the public “was not consistent, and that’s unacceptable.” Pilots are angry with the company for not telling them about possible malfunctions with the implicated software before the crashes occurred. According to FAA officials the safety software can kick in and send a plane into a steep dive even if pilots are manually flying the aircraft. “We clearly had a mistake in the implementation of the alert,” Muilenburg said.

He promised transparency as they work to get the grounded Boeing 737 Max back in flight, and expressed confidence that the model would be cleared to fly again later this year. Regulators first need to approve Boeing’s long-awaited fix to the software on the model, which has been grounded worldwide for three months.