Boeing chief executive Dennis Muilenberg has reaffirmed his expectation that the company will have the grounding of Boeing 737 Max jets lifted by the end of the year.
He expects the company will deliver the 737 Max's updated software to the Federal Aviation Administration (FAA) next month.
Speaking during an investor conference hosted by Jefferies Financial Group on 7 August, Muilenburg said: "We are working through a software update.
"We still anticipate submitting that certification package to the FAA in the September timeframe and are working toward a return to service of the Max in the fourth quarter."
Muilenburg's comments come after Boeing conducted almost 500 test flights containing a new software update to its grounded 737 Max planes.
Several airlines, including American, have shown commitment to Boeing and the 737 Max aircraft with flights scheduled to resume in January.