The chief executive officer of Boeing said the United States-based aircraft maker had made a mistake in installing a faulty cockpit warning system on its 737 MAX planes, Reuters reported.

Dennis Muilenburg’s admission came after two fatal crashes over the last year.

In March, 157 people died when Ethiopian Airlines flight JT610 crashed minutes after takeoff. In October last year, 189 people died when Lion Air’s flight ET302 crashed off the coast of Indonesia.

Both crashes involved the 737 MAX model. In April, Boeing announced plans to cut back production of its 737 MAX aircraft after several countries grounded the aircraft following the crashes.

Muilenburg said on Sunday that Boeing failed to communicate “crisply” with regulators and customers, and admitted that it will take a long time for the plane maker to regain consumer confidence.

However, he defended the company’s broad engineering and design approach to the Boeing 737 MAX planes.

The chief executive said he expects the 737 MAX to return to service this year. Muilenburg added that 90 per cent of the aircraft’s customers have taken part in in simulator sessions with its upgraded MCAS software.

“Clearly, we can make improvements, and we understand that and we will make those improvements,” he said.

Muilenburg said the company is fully supporting the criminal investigation the US Department of Justice has initiated into the two crashes. (NAN)