April 5 (UPI) -- Boeing said Friday it's found a second problem with the software for its 737 Max aircraft, but it's unrelated to the malfunction implicated in two recent crashes.
The aviation company has been studying its anti-stall Maneuvering Characteristics Augmentation System since the crashes in Ethiopia last month and Indonesia last October, which killed a combined 346 people.
After Ethiopian Airlines presented a preliminary report on Thursday, Boeing said data from the flight data recorder indicates the plane had an "erroneous angle of attack sensor input" that activated the automated system during the flight, as it had during the Indonesia flight. To ensure it won't occur again, the company is developing a software update and an expanded pilot training program for the Max fleet.
All 737 Max 8s worldwide are grounded until the modifications are tested and installed.
Boeing didn't specify what the second problem affects, but called it "a relatively minor issue" for which it already has a solution. It added upgraded software will be completed in the coming weeks. Boeing must submit the updates for Federal Aviation Administration approval.
"We're taking a comprehensive, disciplined approach, and taking the time, to get the software update right," Boeing CEO Dennis Muilenburg said in a statement. "We're nearing completion and anticipate its certification and implementation on the 737 MAX fleet worldwide in the weeks ahead. We regret the impact the grounding has had on our airline customers and their passengers."
Critics have questioned in recent weeks whether the FAA jeopardized air safety by outsourcing too much of the certification work. The FAA said Thursday in a letter to Senate Commerce, Science and Transportation Committee Chairman Sen. Roger Wicker, saying their safety inspectors working on Boeing 737 MAX certification "fully qualified."