'We have not blamed the pilots': Boeing CEO

Muilenburg acknowledged errors in failing to give pilots more information on MCAS before the crashes in Ethiopia and Indonesia, as well as for failing to tell the Federal Aviation Administration for months that it made an alarm alerting pilots to a mismatch of flight data optional on the 737 MAX.

The hearing, the highest-profile congressional scrutiny of commercial aviation safety in years, adds pressure on a newly rejigged Boeing senior management team fighting to repair trust with airline customers and passengers shaken by an eight-month safety ban on its 737 MAX following the crashes.

Muilenburg's appearance marks the first time Boeing has appeared at a hearing on Capitol Hill in the year since the first fatal crash, as the company had previously resisted earlier requests to testify.