Boeing Has Completed the Software Update for 737 MAX Planes

Boeing has completed the development of a software update for its imperiled 737 MAX jets, the plane manufacturer said in a release Thursday afternoon.

Updating the 737 MAX's software is a key step to the controversial plane returning to the skies following two deadly crashes.

The software in question controls the MAX's Maneuvering Characteristics Augmentation System (MCAS), which automatically pushes down the aircraft nose if it senses it is tipping too high, risking an aerodynamic stall. Officials have looked at the system and the software behind it possibly playing a role in two similar and MAX crashes, one on Lion Air and one on Ethiopian Airlines.

MCAS became the center of controversy after the first MAX crash on Lion Air flight 610 because pilots accused Boeing of withholding information about the system, saying they weren't told about it, nor was it included in the flight operations manual for the MAX.

Boeing maintains that its 737 MAX planes will be safe to fly with the software update to the MCAS function. The Chicago-based company said Thursday that the new software has been tested on 207 engineering trial flights totaling more than 360 hours.

Boeing CEO Dennis Muilenburg said the company is preparing for the final certification flight with the Federal Aviation Administration, one of the key next steps to rolling out the software update worldwide. The company must also provide additional information to the FAA on how pilots interact with the airplane controls and displays in different flight scenarios.

“We’re committed to providing the FAA and global regulators all the information they need, and to getting it right," Muilenburg said in the release. "We’re making clear and steady progress and are confident that the 737 MAX with updated MCAS software will be one of the safest airplanes ever to fly. The accidents have only intensified our commitment to our values, including safety, quality and integrity, because we know lives depend on what we do.”

All MAX planes have been grounded worldwide after the second fatal crash on Ethiopian Airlines in early March.

US carriers that fly the MAX, including Southwest Airlines and American Airlines, have taken their MAX fleets off flight schedules through August. It remains unclear when the jets might be cleared to fly again.