March 21 (UPI) -- Boeing is working on new software and training procedures for the 737 Max 8 aircraft, which has been grounded around the world after two fatal crashes.
Investigators found similarities between the March 10 crash of Ethiopian Airlines Flight 302, which killed 157 people, and October's Lion Air crash that killed 189 in Indonesia. That prompted airlines and air authorities around the world to ground the 737 Max 8 last week.
The updates to the jet's flight control software, on-board displays, flight manual and training require approval by the Federal Aviation Administration, Boeing Vice President Randy Tinseth said Thursday while speaking at a Bank of America Merrill Lynch conference.
"We have gone through steps such as working with it in a simulator, we flight tested the improvements and we are working with the FAA towards certification and we believe that will happen in coming weeks," Tinseth said.
Investigators are focusing on the stall-prevention system, which experts say forced the plane into a dive after receiving bad data from one sensor. There are no redundancies in the system.
The FBI has joined the investigation being conducted by the Department of Transportation.
That's in addition to a congressional panel set for March 27 to discuss the safety of the 737 Max 8 and aviation in general.
"Given the tragic crashes we've seen in recent weeks, I believe the United States made the right call in temporarily grounding 737 MAX fleet while the FAA validates the safety of these aircraft," said Sen. Ted Cruz, R-Texas, who chairs the subcommittee on aviation and space. "This hearing will examine the recent crashes, possible contributing factors, and ultimately, how we can ensure America's aviation industry remains the safest in the world."
Tinseth said the deaths "deeply felt throughout the organization" but he has "great confidence" in the plane.
The doomed Ethiopian Airlines and Lion Air planes lacked two safety features that could have prevented the deadly crashes. Boeing charges extra for them, so the airlines skipped that upgrade.
The optional safety features would have made it easier for pilots to determine what was going wrong when the sensors started giving erroneous readings.
Neither feature was required by the FAA.
"They're critical, and cost almost nothing for the airlines to install," said Bjorn Fehrm, an analyst at the aviation consultancy Leeham. "Boeing charges for them because it can. But they're vital for safety."