Seattle, Washington - Boeing is working on additional modifications to the flight-control system software of the 737 MAX jets.
The manufacturer decided for further changes when a new flaw was discovered in the software architecture of the 737 MAX's flight-control system in June during a simulator test that was run by the FAA.
The U.S. Federal Aviation Administration said that the new safety risk identified by the agency inspectors would need to be addressed before the aircraft return to service.
During a specific scenario, a failure in a microprocessor caused the aircraft's flight-control system to send an uncommanded movement signal to the elevator that is located on the tail.
According to a Boeing official who spoke to the Seattle Times about the issue, It took pilots too long to recognize the problem.
In the new design, both flight-control computers in the cockpit will provide data rather than one to double-check if the flight-control systems function properly.
Although there are two flight computers on the 737s, including both older models and the MAX series, only one of them is being used for each flight. The system switches to the other flight computer for the following flight.
Boeing has been working on a software fix for the aircraft's anti-stall system (MCAS), which led two deadly crashes in less than half a year.
The manufacturer plans to submit the redesigned software for the approval of international civil aviation regulators including the FAA and EASA.