PARIS (Financial Times) -- Boeing's chief executive has admitted he was "disappointed" that it had not "crisply communicated" information learned by engineers in 2017 about a cockpit alert sensor on the troubled 737 Max aircraft.
More than 300 people died during two crashes of the plane, off Indonesia last October and in Ethiopia in March, which led to the global grounding of the jet.
Airlines have previously said that Boeing did not disclose that certain safety features on the 737 Max aircraft were not operating as they should have, including cockpit alerts designed to warn pilots about faulty sensors.
Addressing the media on the eve of the Paris Air Show and for only the second time since the second crash of the 737 Max in March, Dennis Muilenburg said Boeing's communications were an area where "we could have and should have done better".
The Boeing boss said he was "very confident there will not be another [MCAS-related] accident". He was referring to the faulty manoeuvring characteristics augmentation system that played a role in both crashes.
He insisted that the original MCAS design had been done "according to our design standards" but that Boeing had now improved the system.
The company has said previously that the proposed fix will prevent the system from repeatedly forcing the nose of the Max down under certain circumstances and will also prevent it from being triggered by only one of the two exterior sensors that measure the plane's angle with the ground.
"We are very confident in the design solution that we have come up with, said Mr Muilenburg, stressing that the "accidents continue to weigh heavily on us". They were "something we will never forget," he said. Boeing, he added, had work to do "to re-earn the public's trust".
A growing number of families whose loved ones died in the two crashes are taking legal action against the company.
Boeing and the Federal Aviation Administration face lawsuits and investigations in the US. The US Securities and Exchange Commission has opened a probe into Boeing's disclosures to investors about the Max. That is separate to a criminal investigation by US federal authorities into the initial certification of the jet as safe to fly. Mr Muilenburg said the company was co-operating with all investigations.
The company continues to work on a software fix for MCAS but Mr Muilenburg did not give a timetable as to when the Max would return to the skies. "We are making good steady progress," he said.
Global aviation safety regulators, he said, were "converging together to certify and get the Max back up in the air. We will take the time necessary to ensure that safety is paramount."
The company has initiated training and education updates around the world. Pilots at more than 90 per cent of Max customers have now flown the Max in a simulator setting.
Boeing is also working hard on improving its communications, which Mr Muilenburg admitted was an area where "we could have and should have done better".
Separately, Mr Muilenburg took a swipe at potential plans by European rival Airbus to launch a longer-range version of its single-aisle A321 jet, the A321XLR. Boeing, he said, was continuing to evaluate its own plans for a midsized jet and sticking to its original timeframe of fielding it in 2025. It had so far talked to more than 70 potential customers.
The company, he said, anticipated demand for between 4,000 and 5,000 aeroplanes which would have a range of about 5,000 nautical miles and seat between 220-270 passengers.
Airbus' proposal, said Mr Muilenburg, "is an airplane that would scratch an edge of the middle of the market but . . . ours is one that would really [target] that market".
He said the overall outlook for the commercial, defence and space market remained strong and that Boeing had raised its forecast for overall sales in the sector from $8.1tn to $8.7tn over the next 10 years.