Boeing has announced it is close to completing a 737 Max software update that will address the Lion Air and Ethiopian Airlines accidents.

In a news media briefing, the company has said its updates on the anti-stall system, which may have played a part in the two disasters, had been tested and that Federal Aviation Administration (FAA) regulators had taken test flights on updated jets.

The company has also announced that an optional safety feature, the disagree light, would be made standard on new Max aircraft. The disagree light is a safety feature that activates if two key sensors on the plane do not produce the same readings.

The feature’s proposed inclusion as standard comes in the wake of recent news that the company has been selling certain features, including safety and navigation systems, as optional.

A Boeing official in Seattle said on Wednesday that the timing of the software upgrade was “100 per cent independent of the timing of the Ethiopian accident“, and the company was taking steps to make the anti-stall system “more robust”, according to an ABC report.

On Saturday, pilots from five airlines met in Renton to test how the aircraft would have responded to the Lion Air disaster and to evaluate how it performs with the updated version of the software, The Australian reported. The airlines in attendance include American, United and Southwest.

From results gathered in simulated tests, it was reported that pilots would have been overwhelmed by the Manoeuvring Characteristics Augmentation System (MCAS), which  is designed to pitch the plane down when the anti-stall technology detects an imminent stall.

The New York Times reported the pilots who simulated the MCAS malfunction were surprised by the force of the electrically powered stabiliser trim system, as it overruled the crew and relentlessly pushed the aircraft’s nose down.

The system only operates when pilots are flying manually with wing flaps retracted, just after take-off, The Australian reported.

Virgin Australia has also made arrangements to meet with Boeing regarding the safety of its 737 Max aircraft and the future of its line-up. The company currently does not have any 737 Max aircraft in its fleet.

In a written statement, Boeing CEO Dennis Muilenburg has said the company holds itself to the highest standards of safety, excellence and integrity in its work, “because the stakes could not be higher.”

“Knowing someone’s life depends on your work is an unforgettable feeling, and it’s one shared among all of us at Boeing. We hold ourselves to the highest standards of safety, excellence and integrity in our work because the stakes could not be higher,” The Boeing Company chairman, president and CEO Dennis Muilenburg said.

“With a shared value of safety, be assured that we are bringing all of the resources of The Boeing Company to bear, working together tirelessly to understand what happened and do everything possible to ensure it doesn’t happen again.”

Muilenburg’s came as a response to Ethiopian Airlines Group CEO Tewolde GebreMariam‘s own heartfelt statement that the company’s 70 year history would not be defined by a tragedy.

“It has been more than two weeks since the tragic crash of Ethiopian Airlines flight 302.  The heartbreak for the families of the passengers and crew who perished will be lasting.  This has forever changed their lives, and we at Ethiopian Airlines will feel the pain forever.  I pray that we all continue to find strength in the weeks and months ahead,” GebreMarian said.

“The people of Ethiopia feel this very deeply, too. As a state-owned airline and the flagship carrier for our nation, we carry the torch for the Ethiopian brand around the world. In a nation that sometimes is saddled with negative stereotypes, accidents like this affect our sense of pride.

“Yet this tragedy won’t define us. We pledge to work with Boeing and our colleagues in all the airlines to make air travel even safer.

“As the largest aviation group on the continent of Africa, we represent The New Spirit of Africa and will continue to move forward. We are rated as a four-star global airline with a high safety record and member of Star Alliance. That will not change.”

GebreMariam also confirmed Ethiopian Airlines’ total support of Boeing. The airline’s fleet is composed of more than two thirds Boeing aircraft.

Boeing has stressed that no final conclusions have been made about what caused the crashes of Lion Air Flight 610 in Indonesia in October and Ethiopian Airlines Flight 302 this month.

The company did not provide a timeline for the return of the 737 Max, which is currently grounded around the world. The US FAA has, however, allowed airlines to conduct flights without passengers to move 737 Max aircraft in between airports.

The allowance comes close to reports that a California bound Southwest 737 Max aircraft was forced to make an emergency landing due to an unrelated engine malfunction shortly after take-off from Orlando International Airport.

The incident is being investigated but it was not related to 737 Max anti-stall software, which is the suspected cause of the Lion Air and Ethiopian Airlines crashes.