A Boeing 737 MAX 8 for China Southern Airlines (front) is pictured at the Boeing Renton Factory in Renton, Washington on March 12, 2019.
Jason Redmond | AFP | Getty Images
Boeing shares slipped Friday after a Reuters report said instant messages from 2016 suggest that employees misled the Federal Aviation Administration about a key safety system on the 737 Max, the plane that has been grounded since mid-March after two fatal crashes
The FAA turned over the instant messages to the US lawmakers and the Department of Transportation Inspector General, the FAA said in a statement. The FAA says Boeing discovered the messages "a few months ago" and the flight regulatory agency finds the document "concerning."
"The FAA is also disappointed that Boeing did not bring this document to our attention immediately upon its discovery," the agency said. "The FAA is reviewing this information to determine what action is appropriate."
The document was shared with lawmakers investigating the plane's certification, the FAA added.
Boeing shares were down more than 4% in midday trading , shaving 1
FAA's statement that Boeing knew about the document earlier comes amid mounting pressure on Boeing's CEO Dennis Muilenburg. Boeing is facing several investigations into the plane's design and software.
The company's board removed Muilenburg as chairman last week, saying the division of the two roles will help him focus on bringing the plane back to service. Muilenburg will face lawmakers for the first time since the crashes in a House transportation committee hearing scheduled for Oct. 30.
Boeing is scrambling to gain regulators' approval to bring the plans back to service. Investigators in both crashes – a Lion Air 737 Max that went down in Indonesia in October 2018 and an Ethiopian Airlines plane of the same model that crashed in March – implicated flight-control software in both disasters, which killed 346 people.
Boeing has developed a software fix for the software that misfired on the crashes but regulators have not yet signed off.