Boeing's shares were down 1.4 percent in after-market trading Friday
The FAA, initially calling the plane "airworthy," joined the rest of the world on March 13 in grounding the Max.
At the time, Boeing said it had no plans to cut production and many analysts agreed with the decision. Jose Caiado, airline analyst for Credit Suisse said in mid-March he expected to keep the assembly lines rolling at current levels so it didn't disrupt supply chains.
"They will just have to carry that inventory on their balance sheet a little while longer, "he told CNBC.
Boeing says it hopes to have a software fix for the 737 Max in the coming weeks that it will submit to the FAA and international regulators for approval. Their review and potential certification could take several more weeks, even months, meaning the 737 could be grounded well into June, if not later. Boeing has decided it is smarter to roll fewer 737's out of its plant in Renton, Washington.
Separately, Muilenburg says the Boeing nboard of directors has formed a committee to review our company-wide policies and processes for the design and development of the airplanes we build. "